CN212543744U - Remote transmission type pressure transmitter - Google Patents
Remote transmission type pressure transmitter Download PDFInfo
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- CN212543744U CN212543744U CN202020845013.XU CN202020845013U CN212543744U CN 212543744 U CN212543744 U CN 212543744U CN 202020845013 U CN202020845013 U CN 202020845013U CN 212543744 U CN212543744 U CN 212543744U
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Abstract
The application provides a remote transmission type pressure transmitter which comprises a 4-20mA output circuit, a first power supply circuit, a first filter circuit, a first communication circuit, a control circuit, a second power supply circuit, a second filter circuit, a second communication circuit and a pressure sensing circuit, wherein the first power supply circuit is connected with the first power supply circuit; the 4-20mA output circuit is sequentially connected with the first power circuit, the second filter circuit and the second communication circuit, the 4-20mA output circuit is further sequentially connected with the control circuit, the first communication circuit, the second communication circuit and the pressure sensing circuit, the first filter circuit is respectively connected with the first power circuit and the first communication circuit, the first filter circuit and the second filter circuit are used for filtering power signals and then respectively supplying power to the first communication circuit and the second communication circuit, and the control circuit is used for controlling the first communication circuit and the second communication circuit to intermittently work, so that the anti-interference capability of the remote transmission type pressure transmitter and the accuracy of output 4-20mA current signals can be effectively improved.
Description
Technical Field
The application belongs to the technical field of remote transmission type pressure transmitters and relates to a remote transmission type pressure transmitter.
Background
A remote pressure transmitter is a device that converts pressure into an electrical signal for control and remote transmission. The pressure sensor can convert physical pressure parameters of gas, liquid and other media collected by the pressure sensor into standard 4-20mA electric signals, and the standard electric signals are provided for secondary instruments such as an indication alarm instrument, a recorder, a regulator and the like to carry out pressure measurement, indication and regulation. When the near end and the far end of the existing remote transmission type pressure transmitter are communicated, the near end and the far end are easily interfered by communication current pulses, and the anti-interference capability is poor.
SUMMERY OF THE UTILITY MODEL
The application aims to provide a remote transmission type pressure transmitter, and aims to solve the problems that when the near end and the far end of the existing remote transmission type pressure transmitter are communicated, the near end and the far end are easily interfered by communication current pulses, and the interference resistance is poor.
The embodiment of the application provides a remote transmission type pressure transmitter, which comprises a near end and a far end, wherein the near end comprises a 4-20mA output circuit, a first power circuit, a first filter circuit, a first communication circuit and a control circuit, and the far end comprises a second power circuit, a second filter circuit, a second communication circuit and a pressure sensing circuit;
the 4-20mA output circuit is sequentially connected with the first power supply circuit, the second filter circuit and the second communication circuit, the 4-20mA output circuit is further sequentially connected with the control circuit, the first communication circuit, the second communication circuit and the pressure sensing circuit, and the first filter circuit is respectively connected with the first power supply circuit and the first communication circuit;
the 4-20mA output circuit is used for connecting a power line to input a first power signal to supply power to the first power circuit, the first power circuit is used for converting the first power signal into a second power signal to supply power to the first filter circuit and the control circuit and converting the first power signal into a third power signal to supply power to the second power circuit, the first filter circuit is used for filtering the second power signal to obtain a first communication power signal to supply power to the first communication circuit, the second power circuit is used for converting the third power signal into a fourth power signal to supply power to the second filter circuit, the second filter circuit is used for filtering the fourth power signal to obtain a second communication power signal to supply power to the second communication circuit, and the pressure sensing circuit is used for sampling pressure data of a pressure medium to be measured and sequentially passes through the second communication circuit and the first communication circuit The control circuit is used for processing the pressure data into a pressure value, controlling the first communication circuit and the second communication circuit to work intermittently so as to maintain the voltage of the first communication power supply signal and the voltage of the second communication power supply signal to be constant, and the 4-20mA output circuit is also used for converting the pressure value into a 4-20mA current signal and outputting the 4-20mA current signal to the power line.
In one embodiment, the first filter circuit comprises a first RC filter circuit and the second filter circuit comprises a second RC filter circuit;
the input end, the first output end and the second output end of the first RC filter circuit are respectively connected with the first power supply circuit, the first communication circuit and the ground in a one-to-one correspondence manner;
and the input end, the first output end and the second output end of the second RC filter circuit are respectively connected with the second power supply circuit, the second communication circuit and the ground in a one-to-one correspondence manner.
In one embodiment, the first RC filter circuit comprises a first resistor, a first capacitor and a second capacitor, and the second RC filter circuit comprises a second resistor, a third capacitor and a fourth capacitor;
one end of the first resistor is an input end of the first RC filter circuit, the other end of the first resistor, the anode of the first capacitor and the anode of the second capacitor are connected in common to form a first output end of the first RC filter circuit, and the cathode of the first capacitor and the cathode of the second capacitor are connected in common to form a second output end of the first RC filter circuit;
one end of the second resistor is an input end of the second RC filter circuit, the other end of the second resistor, the anode of the third capacitor and the anode of the fourth capacitor are connected in common to form a first output end of the second RC filter circuit, and the cathode of the third capacitor and the cathode of the fourth capacitor are connected in common to form a second output end of the second RC filter circuit.
In one embodiment, the first power supply circuit includes a DC-DC buck circuit and a first LDO circuit, and the second power supply circuit includes a second LDO circuit;
the power input end of the DC-DC voltage reduction circuit is connected with the 4-20mA output circuit, the power output end of the DC-DC voltage reduction circuit is respectively connected with the power input end of the first LDO circuit and the power input end of the second LDO circuit, the power output end of the first LDO circuit is respectively connected with the first filter circuit and the control circuit, and the power output end of the second LDO circuit is connected with the second filter circuit;
the DC-DC voltage reduction circuit is used for inputting the first power supply signal, reducing the first power supply signal into the second power supply signal and then respectively outputting the second power supply signal to the first LDO circuit and the second LDO circuit;
the first LDO circuit is used for inputting the second power supply signal, reducing the voltage of the second power supply signal into a third power supply signal and then respectively outputting the third power supply signal to the first filter circuit and the control circuit;
the second LDO circuit is used for inputting the second power circuit, reducing the voltage of the second power circuit into a fourth power signal and outputting the fourth power signal to the second filter circuit.
In one embodiment, the DC-DC voltage reduction circuit comprises a low-power DC-DC chip, a third filter circuit, an inductor and a fourth filter circuit;
the power input end and the enable end of the low-power consumption DC-DC chip and the input end of the third filter circuit are connected in common to form the power input end of the DC-DC voltage reduction circuit;
the grounding end of the low-power-consumption DC-DC chip is grounded;
the power output end of the low-power consumption DC-DC chip, one end of the inductor and the input end of the fourth filter circuit are connected together to form the power output end of the DC-DC voltage reduction circuit;
the conversion end of the low-power-consumption DC-DC chip is connected with the other end of the inductor;
the feedback end of the low-power-consumption DC-DC chip is connected with the first output end of the fourth filter circuit;
the output end of the third filter circuit and the second output end of the fourth filter circuit are grounded.
In one embodiment, the first LDO circuit comprises a first LDO chip, a fifth filter circuit, and a sixth filter circuit, the second LDO circuit comprises a second LDO chip, a seventh filter circuit, and an eighth filter circuit;
the power input end of the first LDO chip and the input end of the fifth filter circuit are connected in common to form the power input end of the first LDO circuit, the grounding end of the first LDO chip is grounded, the power output end of the first LDO chip and the input end of the sixth filter circuit are connected in common to form the power output end of the first LDO circuit, and the output end of the fifth filter circuit and the output end of the sixth filter circuit are grounded;
the power input end of the second LDO chip and the input end of the seventh filter circuit are connected in common to form the power input end of the second LDO circuit, the grounding end of the second LDO chip is grounded, the power output end of the second LDO chip and the input end of the eighth filter circuit are connected in common to form the power output end of the second LDO circuit, and the output end of the seventh filter circuit and the output end of the eighth filter circuit are grounded.
In one embodiment, the first communication circuit comprises a first low-power differential communication chip, a first self-receiving control circuit, a first current limiting circuit and a second current limiting circuit, and the second communication circuit comprises a second low-power communication chip, a second self-receiving control circuit, a third current limiting circuit and a fourth current limiting circuit;
the receiving end of the first low-power-consumption differential communication chip is connected with the control circuit, the receiver output enable end and the driver output enable end of the first low-power-consumption differential communication chip are connected with the output end of the first self-receiving control circuit, the output end of the first low-power-consumption differential communication chip is connected with the controlled end of the first self-receiving control circuit and the control circuit, the power end of the first low-power-consumption differential communication chip is connected with the first filter circuit, the positive data end and the negative data end of the first low-power-consumption differential communication chip are respectively connected with one end of the first current-limiting circuit and the first end of the second current-limiting circuit in a one-to-one correspondence manner, and the grounding end of the first low-power-consumption differential communication chip is grounded;
the input end of the first self-transmitting and self-receiving control circuit and the second end of the second current limiting circuit are connected with the first filter circuit;
the receiving end of the second low-power-consumption differential communication chip is connected with the pressure sensing circuit, the receiver output enable end and the driver output enable end of the second low-power-consumption differential communication chip are connected with the output end of the second self-receiving control circuit, the output end of the second low-power-consumption differential communication chip is connected with the controlled end of the second self-receiving control circuit and the pressure sensing circuit, the power end of the second low-power-consumption differential communication chip is connected with the second filter circuit, the positive data end and the negative data end of the second low-power-consumption differential communication chip are respectively connected with one end of the third current limiting circuit and the first end of the fourth current limiting circuit in a one-to-one correspondence manner, and the grounding end of the second low-power-consumption differential communication chip is grounded;
the input end of the second self-transmitting and self-receiving control circuit and the second end of the fourth current limiting circuit are connected with the second filter circuit;
the other end of the third current limiting circuit and the third end of the fourth current limiting circuit are respectively connected with the other end of the first current limiting circuit and the third end of the second current limiting circuit in a one-to-one correspondence mode.
In one embodiment, the first self-transmitting and self-receiving control circuit comprises a first electronic switching tube, a thirteenth resistor, a fourteenth resistor and a fifteenth resistor, and the second self-transmitting and self-receiving control circuit comprises a second electronic switching tube, a sixteenth resistor, a seventeenth resistor and an eighteenth resistor;
the output end of the first electronic switching tube and one end of the thirteenth resistor are connected together to form the output end of the first self-transmitting and self-receiving control circuit, the input end of the first electronic switching tube and one end of the fourteenth resistor are connected together to form the input end of the first self-transmitting and self-receiving control circuit, and the controlled end of the first electronic switching tube is connected with one end of the fifteenth resistor;
the other end of the thirteenth resistor is grounded, and the other end of the fourteenth resistor and the other end of the fifteenth resistor are connected together to form a controlled end of the first self-transmitting and self-receiving control circuit;
the output end of the second electronic switching tube and one end of the sixteenth resistor are connected together to form the output end of the second self-transmitting and self-receiving control circuit, the input end of the second electronic switching tube and one end of the seventeenth resistor are connected together to form the input end of the second self-transmitting and self-receiving control circuit, and the controlled end of the second electronic switching tube is connected with one end of the eighteenth resistor;
the other end of the sixteenth resistor is grounded, and the other end of the seventeenth resistor and the other end of the eighteenth resistor are connected together to form a controlled end of the second self-transmitting and self-receiving control circuit.
In one embodiment, the near end further comprises a HART communication circuit, and the far end further comprises a memory;
the HART communication circuit is respectively connected with the 4-20mA output circuit and the control circuit, and the memory is respectively connected with the second communication circuit and the pressure sensing circuit;
the 4-20mA output circuit is also used for supplying power to the HART communication circuit;
the HART communication circuit is used for being connected with a secondary instrument through the power line;
the memory is used for storing the pressure data and the temperature compensation data which are written into the memory by the secondary instrument sequentially through the HART communication circuit, the control circuit, the first communication circuit and the second communication circuit.
In one embodiment, the pressure sensing circuit includes a pressure sensor, an amplification circuit, and an analog-to-digital conversion circuit;
the amplifying circuit is respectively connected with the pressure sensor and the analog-to-digital conversion circuit, and the analog-to-digital conversion circuit is connected with the second communication circuit;
the pressure sensor is used for sampling pressure data of a measured pressure medium;
the amplifying circuit is used for amplifying the pressure data;
the analog-to-digital conversion circuit is used for performing analog-to-digital conversion on the amplified pressure data.
The embodiment of the application provides a remote pressure transmitter, wherein a 4-20mA output circuit of the remote pressure transmitter is connected with a power line to input a first power signal to supply power to a first power circuit, the first power circuit converts the first power signal into a second power signal to supply power to a first filter circuit and a control circuit, and converts the first power signal into a third power signal to supply power to a second power circuit, the first filter circuit filters the second power signal to obtain a first communication power signal to supply power to the first communication circuit, the second power circuit converts the third power signal into a fourth power signal to supply power to the second filter circuit, the second filter circuit filters the fourth power signal to obtain a second communication power signal to supply power to a second communication circuit, and the pressure sensing circuit samples pressure data of a pressure medium to be detected and outputs the pressure data to the control circuit through the second communication circuit and the first communication circuit in sequence, the control circuit processes pressure data into a pressure value, converts the pressure data into a 4-20mA current signal through the 4-20mA output circuit and outputs the 4-20mA current signal to a power line, and also controls the first communication circuit and the second communication circuit to work intermittently to maintain the voltage of the first communication power supply signal and the voltage of the second communication power supply signal constant, so that the change of the first power supply signal caused by the change of the second power supply signal when the first communication power supply signal changes can be effectively prevented, the change of the first power supply signal caused by the change of the fourth power supply signal when the second communication power supply signal changes is prevented, the interference generated when the 4-20mA current signal changes is prevented, and the anti-interference capability of the remote transmission type pressure transmitter and the precision of the 4-20mA current signal are effectively improved.
Drawings
Fig. 1 is a schematic diagram of a first structure of a remote pressure transmitter according to an embodiment of the present disclosure;
fig. 2 is a schematic circuit diagram of a first filter circuit and a second filter circuit provided in an embodiment of the present application;
fig. 3 is a schematic circuit diagram of a first power circuit and a second power circuit provided in an embodiment of the present application;
fig. 4 is a schematic circuit diagram of a first communication circuit and a second communication circuit according to an embodiment of the present disclosure;
fig. 5 is a schematic structural diagram of a second remote pressure transmitter according to an embodiment of the present disclosure.
Detailed Description
In order to make the technical problems, technical solutions and advantageous effects to be solved by the present application clearer, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.
It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.
As shown in fig. 1, the embodiment of the present application provides a remote pressure transmitter, which includes a proximal end 100 and a distal end 200, wherein the proximal end 100 includes a 4-20mA output circuit 101, a first power circuit 102, a first filter circuit 103, a first communication circuit 104 and a control circuit 105, and the distal end 200 includes a second power circuit 202, a second filter circuit 203, a second communication circuit 204 and a pressure sensing circuit 201.
In application, the far end is in contact with the measured pressure medium, and is used for detecting pressure data of the measured pressure medium and transmitting the pressure data to the components at the near end through the serial data line. The near end is an assembly which is far away from the pressure medium to be detected, is used for being connected with a power line to input a power signal to supply power to the near end and the far end, and converts pressure data into a 4-20mA current signal and then outputs the signal through the power line. The near end and the far end are connected through a serial data line capable of transmitting data in a long distance and a power line capable of transmitting power signals.
In an application, the Serial data line may be a Serial Peripheral Interface (SPI) data line or a Universal Asynchronous Receiver/Transmitter (UART) data line. The UART data line may be an RS485, RS232, or RS422 data line.
As shown in fig. 1, the connection relationship of the components in the remote pressure transmitter provided by the present embodiment is as follows:
the 4-20mA output circuit 101 is sequentially connected with the first power supply circuit 102, the second power supply circuit 202, the second filter circuit 203 and the second communication circuit 204, the 4-20mA output circuit 101 is further sequentially connected with the control circuit 105, the first communication circuit 104, the second communication circuit 204 and the pressure sensing circuit 201, and the first filter circuit 103 is respectively connected with the first power supply circuit 102 and the first communication circuit 104.
In application, the 4-20mA output circuit is sequentially connected with the first power supply circuit, the second filter circuit and the second communication circuit through power lines capable of transmitting power signals, and the first filter circuit is also respectively connected with the first power supply circuit and the first communication circuit through the power lines capable of transmitting power signals. The power supply line may be made of any good electrical conductor, for example, the power supply line may be a copper wire, a silver wire, or an aluminum wire. The 4-20mA output circuit is connected with the control circuit, the first communication circuit, the second communication circuit and the pressure sensing circuit in sequence through serial data lines capable of transmitting data. Illustratively, the 4-20mA output circuit is connected with the control circuit through an SPI data line, the first communication circuit, the second communication circuit and the pressure sensing circuit are sequentially connected through a UART data line, and the UART data line connected between the first communication circuit and the second communication circuit is an RS485 data line.
The working principle of each component in the remote transmission type pressure transmitter provided by the embodiment is as follows:
the 4-20mA output circuit 101 is used for connecting a power line to input a first power supply signal to supply power for the first power supply circuit;
the first power circuit 102 is configured to convert the first power signal into a second power signal to supply power to the first filter circuit 103 and the control circuit 105, and convert the first power signal into a third power signal to supply power to the second power circuit 202;
the first filter circuit 103 is configured to filter the second power signal to obtain a first communication power signal, and supply power to the first communication circuit 104;
the second power supply circuit 202 is configured to convert the third power supply signal into a fourth power supply signal to supply power to the second filter circuit 203;
the second filtering circuit 203 is configured to filter the fourth power signal to obtain a second communication power signal, and supply power to the second communication circuit 204;
the pressure sensing circuit 201 is used for sampling pressure data of a detected pressure medium and outputting the pressure data to the control circuit 105 through the second communication circuit 204 and the first communication circuit 104 in sequence;
the control circuit 105 is configured to process the pressure data into a pressure value, and is further configured to control the first communication circuit 104 and the second communication circuit 204 to operate intermittently, so as to maintain the voltage of the first communication power signal and the voltage of the second communication power signal constant;
the 4-20mA output circuit 101 is also used for converting the pressure value into a 4-20mA current signal and outputting the 4-20mA current signal to a power line.
In application, the voltages of the first power signal, the third power signal and the second power signal are sequentially reduced, the voltages of the second power signal and the fourth power signal can be the same or different, the voltages of the first communication power signal and the second communication power signal can be the same or different, and the voltages of the power signals can be set according to the working voltage of a component to be powered. Specifically, the voltages of the first power signal, the second power signal, the third power signal, the fourth power signal, the first communication power signal, and the second communication power signal may be set to 12V, 3.3V, 5V, 3.3V, and 3.3V, respectively.
In application, the 4-20mA output circuit can be realized by selecting any circuit, device or chip with corresponding functions according to actual needs, for example, an AD5421 type low-power consumption chip.
In application, the first filter circuit and the second filter circuit may be implemented by using a circuit, a device or a chip having a filter function. The first filter circuit has a function of filtering the second power signal to obtain the first communication power signal, and can also filter interference generated by the power signal transmitted between the first communication circuit and the second communication circuit. Similarly, the second filter circuit can filter the interference generated by the power signal transmitted between the first communication circuit and the second communication circuit, in addition to the function of filtering the fourth power signal to obtain the second communication power signal.
In one embodiment, the first filter circuit comprises a first RC filter circuit and the second filter circuit comprises a second RC filter circuit;
the input end, the first output end and the second output end of the first RC filter circuit are respectively connected with the first power supply circuit, the first communication circuit and the ground in a one-to-one correspondence manner;
and the input end, the first output end and the second output end of the second RC filter circuit are respectively connected with the second power supply circuit, the second communication circuit and the ground in a one-to-one correspondence manner.
In application, the first RC filter circuit and the second RC filter circuit may be formed by at least one resistor and at least one capacitor.
As shown in fig. 2, in one embodiment, the first RC filter circuit includes a first resistor R1, a first capacitor C1, and a second capacitor C2, and the second RC filter circuit includes a second resistor R2, a third capacitor C3, and a fourth capacitor C4;
one end of the first resistor R1 is an input terminal VDD2 (for inputting the second power signal) of the first RC filter circuit, the other end of the first resistor R1 is connected with the anode of the first capacitor C1 and the anode of the second capacitor C2 in common to form a first output terminal SVDD1 (for outputting the first communication power signal) of the first RC filter circuit, and the cathode of the first capacitor C1 and the cathode of the second capacitor C2 are connected in common to form a second output terminal (for grounding) of the first RC filter circuit;
one end of the second resistor R2 is an input terminal VDD4 (for inputting a fourth power signal) of the second RC filter circuit, the other end of the second resistor R2 is connected to the anode of the third capacitor C3 and the anode of the fourth capacitor C4 in common to form a first output terminal SVDD2 (for outputting a second communication power signal) of the second RC filter circuit, and the cathode of the third capacitor C3 and the cathode of the fourth capacitor C4 are connected in common to form a second output terminal (for grounding) of the second RC filter circuit.
In an application, the first power circuit may be implemented by a circuit, a device, or a chip having two-stage voltage drop functions, for example, the first power circuit may include two cascaded DC-DC (Direct-current-Direct-current) voltage dropping circuits, two cascaded LDO (low dropout regulator) circuits, or one DC-DC voltage dropping circuit and one LDO circuit. The second power circuit may be implemented by a circuit, a device or a chip with a first voltage drop function, for example, the first power circuit may include a DC-DC voltage drop circuit or an LDO circuit.
In one embodiment, the first power supply circuit includes a DC-DC buck circuit and a first LDO circuit, and the second power supply circuit includes a second LDO circuit;
the power input end of the DC-DC voltage reduction circuit is connected with the 4-20mA output circuit, the power output end of the DC-DC voltage reduction circuit is respectively connected with the power input end of the first LDO circuit and the power input end of the second LDO circuit, the power output end of the first LDO circuit is respectively connected with the first filter circuit and the control circuit, and the power output end of the second LDO circuit is connected with the second filter circuit;
the DC-DC voltage reduction circuit is used for inputting the first power supply signal, reducing the first power supply signal into the second power supply signal and then respectively outputting the second power supply signal to the first LDO circuit and the second LDO circuit;
the first LDO circuit is used for inputting the second power supply signal, reducing the voltage of the second power supply signal into a third power supply signal and then respectively outputting the third power supply signal to the first filter circuit and the control circuit;
the second LDO circuit is used for inputting the second power circuit, reducing the voltage of the second power circuit into a fourth power signal and outputting the fourth power signal to the second filter circuit.
In application, the DC-DC voltage reducing circuit may be specifically implemented by a low power consumption DC-DC chip, and the first LDO circuit and the second LDO circuit may be specifically implemented by LDO chips.
As shown in fig. 3, in one embodiment, the DC-DC voltage reduction circuit includes a low power consumption DC-DC chip U1, a third filter circuit 1021, an inductor L1, and a fourth filter circuit 1022;
the power input end VIN and the enable end EN of the low-power consumption DC-DC chip U1 are connected with the input end of the third filter circuit 1021 to form a power input end VDD1 (used for inputting a first power signal) of the DC-DC voltage reduction circuit;
the grounding end GND of the low-power-consumption DC-DC chip U1 is grounded;
a power output terminal VOUT of the low-power consumption DC-DC chip U1, one end of the inductor L1, and an input terminal of the fourth filter circuit 1022 are commonly connected to form a power output terminal VDD3 (for outputting a third power signal) of the DC-DC voltage reduction circuit;
the switching end SW of the low-power-consumption DC-DC chip U1 is connected with the other end of the inductor L1;
a feedback terminal FB of the low power consumption DC-DC chip U1 is connected to a first output terminal of the fourth filter circuit 1022;
an output terminal of the third filter circuit 1021 and a second output terminal of the fourth filter circuit 1022 are grounded.
In application, the low-power consumption DC-DC chip can be a TSP62122 type chip. The third filter circuit may be formed by at least two capacitors connected in parallel between the power input terminal of the low power consumption DC-DC chip and ground, and the fourth filter circuit may be an RC filter circuit formed by at least one resistor and at least one capacitor.
The third filter circuit 1021 is exemplarily shown in fig. 3 to include a fifth capacitor C5 and a sixth capacitor C6 connected in parallel between the power input terminal VIN of the low power consumption DC-DC chip U1 and the ground;
the fourth filter circuit comprises a third resistor R3, a fourth resistor R4 and a seventh capacitor C7, one end of the third resistor R3 and one end of the seventh capacitor C7 are connected in common to form an input end of the fourth filter circuit 1022, the other end of the third resistor R3, one end of the fourth resistor R4 and one end of the seventh capacitor C7 are connected in common to form a first output end of the fourth filter circuit 1022, and the other end of the fourth resistor R4 forms a second output end of the fourth filter circuit 1022.
As shown in fig. 3, in one embodiment, the first LDO circuit includes a first LDO chip U2, a fifth filter circuit 1023, and a sixth filter circuit 1024, and the second LDO circuit includes a second LDO chip U3, a seventh filter circuit 2021, and an eighth filter circuit 2022;
the power input end IN of the first LDO chip U2 and the input end of the fifth filter circuit 1023 are connected IN common to form a power input end VDD3 (for inputting a third power signal) of the first LDO circuit, the ground end GND of the first LDO chip U2 is grounded, the power output end OUT of the first LDO chip U2 and the input end of the sixth filter circuit 1024 are connected IN common to form a power output end VDD2 (for outputting a second power signal) of the first LDO circuit, the enable end EN and the dead pin NC of the first LDO chip U2 are empty, and the output end of the fifth filter circuit 1023 and the output end of the sixth filter circuit 1024 are grounded;
the power input end IN of the second LDO chip U3 and the input end of the seventh filter circuit 2021 are connected IN common to form a power input end VDD3 (for inputting a third power signal) of the second LDO circuit, the ground end GND of the second LDO chip U3 is grounded, the power output end OUT of the second LDO chip U3 and the input end of the eighth filter circuit 2022 are connected IN common to form a power output end VDD4 (for outputting a fourth power signal) of the second LDO circuit, the enable end EN and the dead pin NC of the second LDO chip U3 are idle, and the output end of the seventh filter circuit 2021 and the output end of the eighth filter circuit 2022 are grounded.
In application, the first LDO chip and the second LDO chip may be specifically XC6201P332M type chips. The fifth filter circuit and the seventh filter circuit may be formed by at least two capacitors connected in parallel between the power output terminal of the low power consumption DC-DC chip and ground, the sixth filter circuit may be formed by at least two capacitors connected in parallel between the power output terminal of the first LDO chip and ground, and the eighth filter circuit may be formed by at least two capacitors connected in parallel between the power output terminal of the second LDO chip and ground.
The fifth filter circuit 1023 exemplarily shown IN fig. 3 includes an eighth capacitor C8 and a ninth capacitor C9 connected IN parallel between the power input terminal IN of the first LDO chip U2 and ground;
the sixth filter circuit 1024 includes a tenth capacitor C10 and an eleventh capacitor C11 connected in parallel between the power output terminal OUT of the first LDO chip U2 and ground;
the seventh filter circuit 2021 includes a twelfth capacitor C12 and a thirteenth capacitor C13 connected IN parallel between the power input terminal IN of the second LDO chip U3 and ground;
the eighth filter circuit 2022 includes a fourteenth capacitor C14 and a fifteenth capacitor C15 connected in parallel between the power output terminal OUT of the second LDO chip U3 and ground.
In application, the first communication circuit and the second communication circuit may be implemented by using a circuit, a device, or a chip having a remote data transmission function, for example, a low power consumption differential communication chip, specifically, an SN65HVD3082 type low power consumption RS485 communication chip may be used.
As shown in fig. 4, in one embodiment, the first communication circuit 104 includes a first low power consumption differential communication chip U4, a first self-receiving control circuit 1041, a first current limiting circuit 1042 and a second current limiting circuit 1043, and the second communication circuit 204 includes a second low power consumption communication chip U5, a second self-receiving control circuit 2041, a third current limiting circuit 2042 and a fourth current limiting circuit 2043;
a receiving end R of the first low-power-consumption differential communication chip U4 is connected with the control circuit 105, a receiver output enable end/RE and a driver output enable end DE of the first low-power-consumption differential communication chip U4 are connected with an output end of the first self-receiving control circuit 1041, an output end D of the first low-power-consumption differential communication chip U4 is connected with a controlled end TXD1 and the control circuit 105 of the first self-receiving control circuit 1041, a power supply end VCC (SVDD1) of the first low-power-consumption differential communication chip U4 is connected with the first filter circuit 103, a data positive end a and a data negative end B of the first low-power-consumption differential communication chip U4 are respectively connected with one end of the first current-limiting circuit 1042 and a first end of the second current-limiting circuit 1043 in a one-to-one correspondence, and a ground end GND of the first low-power-consumption differential communication chip U4;
an input end SVDD1 of the first self-receiving and self-transmitting control circuit 1041 and a second end SVDD1 of the second current limiting circuit 1043 are connected with the first filter circuit 103;
a receiving end R of the second low-power-consumption differential communication chip U5 is connected with the pressure sensing circuit 201, a receiver output enable end/RE and a driver output enable end DE of the second low-power-consumption differential communication chip U5 are connected with an output end of the second self-receiving control circuit 2041, an output end of the second low-power-consumption differential communication chip U5 is connected with a controlled end TXD2 and the pressure sensing circuit 201 of the second self-receiving control circuit 2041, a power supply end VCC (SVDD2) of the second low-power-consumption differential communication chip U5 is connected with the second filter circuit 203, a data positive end a and a data negative end B of the second low-power-consumption differential communication chip U5 are respectively connected with one end of the third current limiting circuit 2042 and a first end of the fourth current limiting circuit 2043 in a one-to-one correspondence, and a ground GND end of the second low-power-consumption differential communication chip U5 is grounded;
an input end SVDD2 of the second self-receiving control circuit 2041 and a second end SVDD2 of the fourth current limiting circuit 2043 are connected with the second filter circuit 203;
the other end RS485-A of the third current limiting circuit 2042 and the third end RS485-B of the fourth current limiting circuit 2043 are respectively connected with the other end RS485-A of the first current limiting circuit 1042 and the third end RS485-B of the second current limiting circuit 1043 in a one-to-one correspondence manner.
In application, the first to fourth current limiting circuits may be constituted by at least one resistor.
Fig. 4 exemplarily shows that the first current limiting circuit 1042 includes a fifth resistor R5 and a sixth resistor R6, one end of the fifth resistor R5 is grounded, the other end of the fifth resistor R5 and one end of the sixth resistor R6 are commonly connected to form one end of the first current limiting circuit 1042, and the other end of the sixth resistor R6 forms the other end RS485-a of the first current limiting circuit 1042;
the second current limiting circuit 1043 comprises a seventh resistor R7 and an eighth resistor R8, one end of the seventh resistor R7 forms a second end SVDD1 of the second current limiting circuit 1043, the other end of the seventh resistor R7 and one end of the eighth resistor R8 are connected in common to form a first end of the second current limiting circuit 1043, and the other end of the eighth resistor R8 forms a third end RS485-B of the second current limiting circuit 1043;
the third current limiting circuit 2042 includes a ninth resistor R9 and a tenth resistor R10, one end of the ninth resistor R9 is grounded, the other end of the ninth resistor R9 and one end of the tenth resistor R10 are commonly connected to form one end of the second current limiting circuit 2042, and the other end of the tenth resistor R10 forms the other end RS485-a of the second current limiting circuit 2042;
the fourth current limiting circuit 2043 includes an eleventh resistor R11 and a twelfth resistor R12, one end of the eleventh resistor R11 forms a second end SVDD2 of the fourth current limiting circuit 2043, the other end of the eleventh resistor R11 and one end of the twelfth resistor R12 are commonly connected to form a first end of the fourth current limiting circuit 2043, and the other end of the twelfth resistor R12 forms a third end RS485-B of the fourth current limiting circuit 2043.
As shown in fig. 4, in one embodiment, the first self-receiving control circuit 1041 includes a first electronic switch Q1, a thirteenth resistor R13, a fourteenth resistor R14 and a fifteenth resistor R15, and the second self-receiving control circuit 2041 includes a second electronic switch Q2, a sixteenth resistor R16, a seventeenth resistor R17 and an eighteenth resistor R18;
the output end of the first electronic switching tube Q1 and one end of the thirteenth resistor R13 are connected together to form the output end of the first self-receiving control circuit 1041, the input end of the first electronic switching tube Q1 and one end of the fourteenth resistor R14 are connected together to form the input end SVDD1 of the first self-receiving control circuit 1041, and the controlled end of the first electronic switching tube Q1 is connected with one end of the fifteenth resistor R15;
the other end of the thirteenth resistor R13 is grounded, and the other end of the fourteenth resistor R14 and the other end of the fifteenth resistor R15 are commonly connected to form a controlled end TXD1 of the first self-generating and self-receiving control circuit 1041;
the output end of the second electronic switching tube Q2 and one end of the sixteenth resistor R16 are connected together to form the output end of the second self-receiving control circuit 2041, the input end of the second electronic switching tube Q2 and one end of the seventeenth resistor R17 are connected together to form the input end SVDD2 of the second self-receiving control circuit 2041, and the controlled end of the second electronic switching tube Q2 is connected with one end of the eighteenth resistor R18;
the other end of the sixteenth resistor R16 is grounded, and the other end of the seventeenth resistor R17 and the other end of the eighteenth resistor R18 are commonly connected to form a controlled terminal TXD2 of the second self-receiving and transmitting control circuit 2041.
In application, the first electronic switch tube and the second electronic switch tube can select any type of transistor according to actual needs, for example, a field effect transistor or a triode. Fig. 4 exemplarily shows that the first electronic switch Q1 and the second electronic switch Q2 are both PNP transistors.
As shown in fig. 5, in one embodiment, the near end 100 further comprises a HART (Highway Addressable Remote transmitter) communication circuit 106, and the far end 200 further comprises a memory 205;
the HART communication circuit 106 is respectively connected with the 4-20mA output circuit 101 and the control circuit 105, and the memory 205 is respectively connected with the second communication circuit 204 and the pressure sensing circuit 201;
the 4-20mA output circuit 101 is also used for supplying power to the HART communication circuit 106;
the HART communication circuit 106 is used to connect the secondary instrument through the power line;
the memory 205 is used for storing pressure data and temperature compensation data which are written into the memory 205 by the secondary instrument sequentially through the HART communication circuit 106, the control circuit 105, the first communication circuit 104 and the second communication circuit 204.
In application, the HART communication circuit can be implemented by selecting any circuit, device or chip with corresponding function according to actual needs, for example, an AD5700 type low power consumption chip. The HART communication circuit and the 4-20mA output circuit can be connected with a power line through a two-wire system connecting wire. The memory may be a non-volatile memory (NVM), such as a ferroelectric memory (FRAM).
In Application, the control Circuit may be a Central Processing Unit (CPU), other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf Programmable Gate Array (FPGA) or other Programmable logic device, a discrete Gate or transistor logic device, a discrete hardware component, and the like. The general purpose processor may be a Microprocessor (MCU) or the processor may be any conventional processor or the like. The control of the first communication circuit and the second communication circuit to operate intermittently means that the first communication circuit and the second communication circuit are controlled to operate for a second preset time every interval of a first preset time, the first preset time and the second preset time can be set to be the same or different time lengths according to actual needs, for example, the first preset time and the second preset time can be 5 minutes.
In application, the secondary instrument can be an HART manual operator, an indication alarm instrument, a recorder, a regulator and the like. The pressure data sampled by the pressure sensing circuit at different temperatures have different errors, and the temperature compensation data are used for carrying out error compensation on the pressure data sampled by the pressure sensing circuit at different temperatures, so that the error of the pressure data is within the allowed maximum error range, and the precision and the accuracy of the pressure data output by the remote pressure transmitter are improved. The pressure data and the temperature compensation data are stored in the memory, so that a user can call the historical stored pressure data at any time when needed through the secondary instrument to analyze the pressure change condition of the pressure medium to be detected, and can call the temperature compensation data to perform error compensation when the error of the pressure data is not within the allowed maximum error range.
As shown in fig. 5, in one embodiment, the pressure sensing circuit 201 includes a pressure sensor 2011, an amplification circuit 2012, and an analog-to-digital conversion circuit 2013;
the amplifying circuit 2012 is respectively connected with the pressure sensor 2011 and the analog-to-digital conversion circuit 2013, and the analog-to-digital conversion circuit 2013 is connected with the second communication circuit 204;
the pressure sensor 2011 is used for sampling pressure data of the measured pressure medium;
the amplifying circuit 2012 is used for amplifying the pressure data;
the analog-to-digital conversion circuit 2013 is used for performing analog-to-digital conversion on the amplified pressure data.
In application, the pressure sensor can be a pressure sensor capable of sampling the measured pressure medium according to the type adaptability of the measured pressure medium, for example, when the measured pressure medium is solid, the pressure sensor can be a force balance type pressure sensor; when the pressure medium to be measured is gas or liquid, the pressure sensor can be a capacitance type, inductance type, strain type or frequency type pressure sensor.
In application, the amplifying circuit can be implemented by selecting any circuit, chip or device with a signal amplifying function according to actual needs, for example, an amplifier.
In application, an analog-to-digital conversion (ADC) circuit may be implemented by selecting any circuit, chip or device with an ADC function according to actual needs, for example, an ADS122C04 type ADC sampling chip with low power consumption.
The embodiment of the application provides a remote pressure transmitter, wherein a 4-20mA output circuit of the remote pressure transmitter is connected with a power line to input a first power signal to supply power to a first power circuit, the first power circuit converts the first power signal into a second power signal to supply power to a first filter circuit and a control circuit, and converts the first power signal into a third power signal to supply power to a second power circuit, the first filter circuit filters the second power signal to obtain a first communication power signal to supply power to the first communication circuit, the second power circuit converts the third power signal into a fourth power signal to supply power to the second filter circuit, the second filter circuit filters the fourth power signal to obtain a second communication power signal to supply power to a second communication circuit, and the pressure sensing circuit samples pressure data of a pressure medium to be detected and outputs the pressure data to the control circuit through the second communication circuit and the first communication circuit in sequence, the control circuit processes pressure data into a pressure value, converts the pressure data into a 4-20mA current signal through the 4-20mA output circuit and outputs the 4-20mA current signal to a power line, and also controls the first communication circuit and the second communication circuit to work intermittently to maintain the voltage of the first communication power supply signal and the voltage of the second communication power supply signal constant, so that the change of the first power supply signal caused by the change of the second power supply signal when the first communication power supply signal changes can be effectively prevented, the change of the first power supply signal caused by the change of the fourth power supply signal when the second communication power supply signal changes is prevented, the interference generated when the 4-20mA current signal changes is prevented, and the anti-interference capability of the remote transmission type pressure transmitter and the precision of the 4-20mA current signal are effectively improved; the remote transmission type pressure transmitter is realized by adopting various low-power chips, so that the power consumption of the remote transmission type pressure transmitter can be effectively reduced; the communication between the near end and the far end is realized by adopting an RS485 data line, the transmission distance is long, and the anti-interference capability is strong.
The above-mentioned embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.
Claims (10)
1. A remote transmission type pressure transmitter is characterized by comprising a near end and a far end, wherein the near end comprises a 4-20mA output circuit, a first power supply circuit, a first filter circuit, a first communication circuit and a control circuit, and the far end comprises a second power supply circuit, a second filter circuit, a second communication circuit and a pressure sensing circuit;
the 4-20mA output circuit is sequentially connected with the first power supply circuit, the second filter circuit and the second communication circuit, the 4-20mA output circuit is further sequentially connected with the control circuit, the first communication circuit, the second communication circuit and the pressure sensing circuit, and the first filter circuit is respectively connected with the first power supply circuit and the first communication circuit;
the 4-20mA output circuit is used for connecting a power line to input a first power signal to supply power to the first power circuit, the first power circuit is used for converting the first power signal into a second power signal to supply power to the first filter circuit and the control circuit and converting the first power signal into a third power signal to supply power to the second power circuit, the first filter circuit is used for filtering the second power signal to obtain a first communication power signal to supply power to the first communication circuit, the second power circuit is used for converting the third power signal into a fourth power signal to supply power to the second filter circuit, the second filter circuit is used for filtering the fourth power signal to obtain a second communication power signal to supply power to the second communication circuit, and the pressure sensing circuit is used for sampling pressure data of a pressure medium to be measured and sequentially passes through the second communication circuit and the first communication circuit The control circuit is used for processing the pressure data into a pressure value, controlling the first communication circuit and the second communication circuit to work intermittently so as to maintain the voltage of the first communication power supply signal and the voltage of the second communication power supply signal to be constant, and the 4-20mA output circuit is also used for converting the pressure value into a 4-20mA current signal and outputting the 4-20mA current signal to the power line.
2. The remote pressure transmitter of claim 1 wherein the first filter circuit comprises a first RC filter circuit and the second filter circuit comprises a second RC filter circuit;
the input end, the first output end and the second output end of the first RC filter circuit are respectively connected with the first power supply circuit, the first communication circuit and the ground in a one-to-one correspondence manner;
and the input end, the first output end and the second output end of the second RC filter circuit are respectively connected with the second power supply circuit, the second communication circuit and the ground in a one-to-one correspondence manner.
3. The remote pressure transmitter of claim 2 wherein the first RC filter circuit comprises a first resistor, a first capacitor, and a second capacitor, and the second RC filter circuit comprises a second resistor, a third capacitor, and a fourth capacitor;
one end of the first resistor is an input end of the first RC filter circuit, the other end of the first resistor, the anode of the first capacitor and the anode of the second capacitor are connected in common to form a first output end of the first RC filter circuit, and the cathode of the first capacitor and the cathode of the second capacitor are connected in common to form a second output end of the first RC filter circuit;
one end of the second resistor is an input end of the second RC filter circuit, the other end of the second resistor, the anode of the third capacitor and the anode of the fourth capacitor are connected in common to form a first output end of the second RC filter circuit, and the cathode of the third capacitor and the cathode of the fourth capacitor are connected in common to form a second output end of the second RC filter circuit.
4. The remote pressure transmitter of any of claims 1-3, wherein the first power circuit comprises a DC-DC buck circuit and a first LDO circuit, and the second power circuit comprises a second LDO circuit;
the power input end of the DC-DC voltage reduction circuit is connected with the 4-20mA output circuit, the power output end of the DC-DC voltage reduction circuit is respectively connected with the power input end of the first LDO circuit and the power input end of the second LDO circuit, the power output end of the first LDO circuit is respectively connected with the first filter circuit and the control circuit, and the power output end of the second LDO circuit is connected with the second filter circuit;
the DC-DC voltage reduction circuit is used for inputting the first power supply signal, reducing the first power supply signal into the second power supply signal and then respectively outputting the second power supply signal to the first LDO circuit and the second LDO circuit;
the first LDO circuit is used for inputting the second power supply signal, reducing the voltage of the second power supply signal into a third power supply signal and then respectively outputting the third power supply signal to the first filter circuit and the control circuit;
the second LDO circuit is used for inputting the second power circuit, reducing the voltage of the second power circuit into a fourth power signal and outputting the fourth power signal to the second filter circuit.
5. The remote pressure transmitter of claim 4 wherein the DC-DC voltage reduction circuit comprises a low power DC-DC chip, a third filter circuit, an inductor, and a fourth filter circuit;
the power input end and the enable end of the low-power consumption DC-DC chip and the input end of the third filter circuit are connected in common to form the power input end of the DC-DC voltage reduction circuit;
the grounding end of the low-power-consumption DC-DC chip is grounded;
the power output end of the low-power consumption DC-DC chip, one end of the inductor and the input end of the fourth filter circuit are connected together to form the power output end of the DC-DC voltage reduction circuit;
the conversion end of the low-power-consumption DC-DC chip is connected with the other end of the inductor;
the feedback end of the low-power-consumption DC-DC chip is connected with the first output end of the fourth filter circuit;
the output end of the third filter circuit and the second output end of the fourth filter circuit are grounded.
6. The remote pressure transmitter of claim 4, wherein the first LDO circuit comprises a first LDO chip, a fifth filter circuit, and a sixth filter circuit, and the second LDO circuit comprises a second LDO chip, a seventh filter circuit, and an eighth filter circuit;
the power input end of the first LDO chip and the input end of the fifth filter circuit are connected in common to form the power input end of the first LDO circuit, the grounding end of the first LDO chip is grounded, the power output end of the first LDO chip and the input end of the sixth filter circuit are connected in common to form the power output end of the first LDO circuit, and the output end of the fifth filter circuit and the output end of the sixth filter circuit are grounded;
the power input end of the second LDO chip and the input end of the seventh filter circuit are connected in common to form the power input end of the second LDO circuit, the grounding end of the second LDO chip is grounded, the power output end of the second LDO chip and the input end of the eighth filter circuit are connected in common to form the power output end of the second LDO circuit, and the output end of the seventh filter circuit and the output end of the eighth filter circuit are grounded.
7. The remote pressure transmitter according to any one of claims 1 to 3, wherein the first communication circuit comprises a first low power consumption differential communication chip, a first self-receiving control circuit, a first current limiting circuit and a second current limiting circuit, and the second communication circuit comprises a second low power consumption communication chip, a second self-receiving control circuit, a third current limiting circuit and a fourth current limiting circuit;
the receiving end of the first low-power-consumption differential communication chip is connected with the control circuit, the receiver output enable end and the driver output enable end of the first low-power-consumption differential communication chip are connected with the output end of the first self-receiving control circuit, the output end of the first low-power-consumption differential communication chip is connected with the controlled end of the first self-receiving control circuit and the control circuit, the power end of the first low-power-consumption differential communication chip is connected with the first filter circuit, the positive data end and the negative data end of the first low-power-consumption differential communication chip are respectively connected with one end of the first current-limiting circuit and the first end of the second current-limiting circuit in a one-to-one correspondence manner, and the grounding end of the first low-power-consumption differential communication chip is grounded;
the input end of the first self-transmitting and self-receiving control circuit and the second end of the second current limiting circuit are connected with the first filter circuit;
the receiving end of the second low-power-consumption differential communication chip is connected with the pressure sensing circuit, the receiver output enable end and the driver output enable end of the second low-power-consumption differential communication chip are connected with the output end of the second self-receiving control circuit, the output end of the second low-power-consumption differential communication chip is connected with the controlled end of the second self-receiving control circuit and the pressure sensing circuit, the power end of the second low-power-consumption differential communication chip is connected with the second filter circuit, the positive data end and the negative data end of the second low-power-consumption differential communication chip are respectively connected with one end of the third current limiting circuit and the first end of the fourth current limiting circuit in a one-to-one correspondence manner, and the grounding end of the second low-power-consumption differential communication chip is grounded;
the input end of the second self-transmitting and self-receiving control circuit and the second end of the fourth current limiting circuit are connected with the second filter circuit;
the other end of the third current limiting circuit and the third end of the fourth current limiting circuit are respectively connected with the other end of the first current limiting circuit and the third end of the second current limiting circuit in a one-to-one correspondence mode.
8. The remote pressure transmitter of claim 7 wherein the first self-transmitting and self-receiving control circuit comprises a first electronic switch, a thirteenth resistor, a fourteenth resistor and a fifteenth resistor, and the second self-transmitting and self-receiving control circuit comprises a second electronic switch, a sixteenth resistor, a seventeenth resistor and an eighteenth resistor;
the output end of the first electronic switching tube and one end of the thirteenth resistor are connected together to form the output end of the first self-transmitting and self-receiving control circuit, the input end of the first electronic switching tube and one end of the fourteenth resistor are connected together to form the input end of the first self-transmitting and self-receiving control circuit, and the controlled end of the first electronic switching tube is connected with one end of the fifteenth resistor;
the other end of the thirteenth resistor is grounded, and the other end of the fourteenth resistor and the other end of the fifteenth resistor are connected together to form a controlled end of the first self-transmitting and self-receiving control circuit;
the output end of the second electronic switching tube and one end of the sixteenth resistor are connected together to form the output end of the second self-transmitting and self-receiving control circuit, the input end of the second electronic switching tube and one end of the seventeenth resistor are connected together to form the input end of the second self-transmitting and self-receiving control circuit, and the controlled end of the second electronic switching tube is connected with one end of the eighteenth resistor;
the other end of the sixteenth resistor is grounded, and the other end of the seventeenth resistor and the other end of the eighteenth resistor are connected together to form a controlled end of the second self-transmitting and self-receiving control circuit.
9. The remote pressure transmitter of any of claims 1-3, wherein the proximal end further comprises HART communication circuitry and the distal end further comprises memory;
the HART communication circuit is respectively connected with the 4-20mA output circuit and the control circuit, and the memory is respectively connected with the second communication circuit and the pressure sensing circuit;
the 4-20mA output circuit is also used for supplying power to the HART communication circuit;
the HART communication circuit is used for being connected with a secondary instrument through the power line;
the memory is used for storing the pressure data and the temperature compensation data which are written into the memory by the secondary instrument sequentially through the HART communication circuit, the control circuit, the first communication circuit and the second communication circuit.
10. The remote pressure transmitter of any one of claims 1 to 3 wherein the pressure sensing circuit comprises a pressure sensor, an amplifying circuit and an analog-to-digital conversion circuit;
the amplifying circuit is respectively connected with the pressure sensor and the analog-to-digital conversion circuit, and the analog-to-digital conversion circuit is connected with the second communication circuit;
the pressure sensor is used for sampling pressure data of a measured pressure medium;
the amplifying circuit is used for amplifying the pressure data;
the analog-to-digital conversion circuit is used for performing analog-to-digital conversion on the amplified pressure data.
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| CN202020845013.XU CN212543744U (en) | 2020-05-19 | 2020-05-19 | Remote transmission type pressure transmitter |
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| CN202020845013.XU CN212543744U (en) | 2020-05-19 | 2020-05-19 | Remote transmission type pressure transmitter |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN116399421A (en) * | 2023-04-14 | 2023-07-07 | 河北巨波科技有限公司 | 80G frequency modulation radar liquid level gauge |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN116399421A (en) * | 2023-04-14 | 2023-07-07 | 河北巨波科技有限公司 | 80G frequency modulation radar liquid level gauge |
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