CN201616023U

CN201616023U - Signal isolation conversion output module

Info

Publication number: CN201616023U
Application number: CN2010201342751U
Authority: CN
Inventors: 周卫; 于广沅
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-03-16
Filing date: 2010-03-16
Publication date: 2010-10-27
Anticipated expiration: 2020-03-16

Abstract

The utility model relates to a signal isolation conversion output module, which comprises a bus communication processing module, a singlechip, a digital signal isolation module, a power supply isolation module, a digital-to-analogue conversion module and a signal output conditioning module and is characterized in that the bus communication processing module comprises a chip capable of transforming a TTL level being into an RS-232 level and a chip capable of transforming the TTL level into an RS-485 level; the digital signal isolation module consists of four high-speed photoelectrical coupling isolation chips; the power supply isolation module comprises an over voltage and reverse-connection prevention protective circuit, a filter circuit, a depressurization switch voltage stabilization circuit and a DC-DC isolation module power supply; and the digital-to-analogue conversion module consists of a digital-to-analogue conversion chip and a gate circuit chip. The signal isolation conversion output module can realize the reliable conversion of an RS-232 or RS-485 signal to a 4-20mA analog signal and control remote equipment more conveniently, and a whole signal control system has stronger anti-interference performance, therefore, the EMC interference on the power supply can be effectively inhibited, the control accuracy is improved, the degree of intellectualization is high, and the cost is lowered.

Description

Signal Spacing conversion output module

[technical field]

The utility model relates to commercial unit control field, relates in particular to a kind of RS-232 or the RS-485 Signal Spacing converts the simulating signal output module to.

[background technology]

Along with science and technology development, fields such as industry spot, power monitoring, Medical Devices, experimental study are also more and more to the demand of Remote Device Control.In view of attention degree to its result, and to the control accuracy of Remote Device Control module, antijamming capability, safe reliability, intelligent degree, communications protocol, mounting meanss etc. all have the higher requirement of ratio.

In common rig-site utilization, actuator and actuating equipment are all accepted the current signal of 4-20mA, and generally do not have the interface of 4-20mA simulating signal output as the computer of host computer, therefore use RS-232 or RS-485 Signal Spacing and convert the simulating signal output module to and can address this problem easily.RS-232 is most widely used a kind of serial line interface in computer and the communication industry at present.RS-232 is defined as a kind of single-ended standard that increases communication distance in the low rate serial communication.RS-232 takes uneven transmission mode, promptly so-called single-ended communication.RS-485 then not only can realize point-to-point communication mode but also can realize network savvy.

In addition, because the long Distance Transmission of signal, voltage difference between the ground wire of host computer and actuating equipment may reach tens volts, a few hectovolt or even several kilovolts, do not isolate if directly adopt digital-to-analog conversion, just have error in data, inaccurate, phenomenon such as beat, also can damage upper machine communication mouth and actuating equipment in the time of serious, so realize that the communication interface of module and mutual isolation of simulation output are inexorable trends.

[summary of the invention]

The utility model at above problem a kind of RS-232 or RS-485 communication interface have been proposed especially, isolate output analog current signal, output signal accurately, be not easy to be interfered, RS-232 or RS-485 Signal Spacing conversion output module that reliability greatly improves.

The technical solution of the utility model is: described Signal Spacing conversion output module has comprised that bus communication processing module, single-chip microcomputer, digital signal are isolated module, power supply is isolated module, digital-to-analog conversion module and signal output conditioning module.Its characteristics are, described bus communication is handled module and is included a Transistor-Transistor Logic level commentaries on classics RS-232 level chip U5 and a Transistor-Transistor Logic level commentaries on classics RS-485 level chip U6, and described digital signal is isolated module by high speed optoelectronic coupling isolating chip ISO1, ISO2, ISO3, ISO4 forms; Described power supply is isolated module and is comprised an overvoltage and anti-reverse holding circuit, filtering circuit and a step-down switching mu balanced circuit and a DC-DC isolation module power supply U; Described digital-to-analog conversion module is made up of analog-digital chip U1 and gate circuit chip U15.

Overvoltage and anti-reverse holding circuit that described power supply is isolated module comprise an anti-reverse protection diode D81 and a TVS pipe ZD81.Described filtering circuit comprises electrochemical capacitor C81 and ceramic condenser C82, and described electrochemical capacitor C81 and ceramic condenser C82 are that parallel connection is linked in the circuit.Described step-down switching mu balanced circuit comprises lowering and stabilizing blood pressure chip U8, diode D82,81, one inductance capacitance C83 of an inductance L.

What the Physical layer of described bus communication processing module adopted is RS-232 or RS-485 agreement.

The beneficial effects of the utility model are: realized the reliable conversion to the 4-20mA simulating signal of RS-232 or RS-485 signal, the control remote equipment is convenient.Because mutual isolation and isolation voltage are up to 3000VDC between RS-232 or RS-485 communication interface circuit and the simulating signal output circuit, so can not produce undesired signals such as circulation when carrying out remote signal control between the ground wire because of pressure reduction, make whole whistle control system interference free performance stronger.The present invention effectively suppress Long-distance Control interfere with each other with power supply on EMC disturb, improved the precision of control, intelligent degree height, cost is lower.Can be widely used in industrial automation equipment, industry control instrument and meter, reach other manufacturing industries, realize that RS-232 or RS-485 Signal Spacing convert simulating signal output to.

[description of drawings]

Fig. 1 is the whole principle flow chart of the utility model;

Fig. 2 (a) is that the utility model power supply is isolated module part circuit diagram;

Fig. 2 (b) is that the utility model power supply is isolated module another part circuit diagram;

Fig. 3 is the utility model signal output conditioning modular circuit figure.

Wherein: 1, bus communication processing module; 2, single-chip microcomputer; 3, digital signal is isolated module; 4, power supply isolation module; 5, digital-to-analog conversion module; 6, signal output conditioning module.

[embodiment]

In order to make the purpose of this utility model, technical scheme and advantage clearer,, the utility model is further elaborated below in conjunction with drawings and Examples.

Visible with reference to the accompanying drawings the utility model has comprised that bus communication processing module 1, single-chip microcomputer 2, digital signal are isolated module 3, power supply is isolated module 4, digital-to-analog conversion module 5 and signal output conditioning module 6.Its characteristics are that described bus communication is handled module and included a Transistor-Transistor Logic level commentaries on classics RS-232 level chip U5 and a Transistor-Transistor Logic level commentaries on classics RS-485 level chip U6, is responsible for carrying out communication with host computer.Described single-chip microcomputer U2 handles the host computer signal of input, includes zero point correction, the full scale calibration, and the data layout conversion, the communications protocol setting, the baud rate setting, reset values is set or the like.When requiring to set output data, single-chip microcomputer 2 output set of number signals are isolated module 3 through digital signal and are isolated, described digital signal is isolated module 3 by high speed optoelectronic coupling isolating chip ISO1, ISO2, ISO3, ISO4 forms, and finishes the isolation of 4 way word signals.Digital signal after the isolation enters into digital-to-analog conversion module 5 and carries out digital-to-analog conversion, described digital-to-analog conversion module 5 is made up of analog-digital chip U1 and gate circuit chip U15, enters analog-digital chip U1 after the signal process gate circuit chip U15 shaping of digital signal isolation module 3 outputs is handled and converts analog voltage signal to.Analog voltage signal converts current signal to through signal output conditioning module 6, after described signal output conditioning module 6 receives analog voltage signal, enter the in-phase end of amplifier U7A behind the first-order filtering through resistance R 72 and capacitor C 73, the end of oppisite phase of amplifier is connected with resistance R 71 output terminal to ground wire and resistance R 73 to amplifier, and the amplifying circuit of being made up of amplifier U7A and resistance R 71 and resistance R 73 is with the voltage signal amplification of input.Voltage signal after the amplification is input to the in-phase end of amplifier U10B, the output terminal output current signal of amplifier U10B, resistance R 102 be used for the sampling electric current of output, amplifier U12A, amplifier U12B and resistance R 120, R121, R122, R123, R124, R125, R126, R127, R128, differential amplifier of R129 composition carry out the difference amplification to the voltage at resistance R 102 two ends, output to the end of oppisite phase of amplifier U10B then, control output current as feedback and change with input voltage.Capacitor C 104 is used for the ripple of filtering output current.

Described power supply is isolated module 4 and is comprised an overvoltage and anti-reverse holding circuit, filtering circuit and a step-down switching mu balanced circuit and a DC-DC isolation module power supply U9; modular power source U9 isolates one group of positive supply of output and one group of negative supply with the power supply signal of input, amplifier and the analog-digital chip power supply of power supply through giving output terminal after the filtering.Overvoltage, overcurrent and anti-reverse holding circuit that described power supply is isolated module comprise an anti-reverse protection diode D81 and a TVS pipe ZD81, realize the purpose that prevents that the spike undesired signal from disturbing.Described filtering circuit comprises electrochemical capacitor C81 and ceramic condenser C82, and described electrochemical capacitor C81 and ceramic condenser C82 are that parallel connection is linked in the circuit.Next be directly connected to step-down switching voltage stabilizing chip U8, switch voltage-stabilizing chip U8 and a diode D82, an inductance L 81, an electrochemical capacitor C83 forms a switch voltage-stabilizing circuit, by stable power voltage to one DC-DC isolation module power supply U9 of this switch voltage-stabilizing circuit output, modular power source U9 isolates one group of positive supply of output and one group of negative supply with the power supply signal of input, wherein positive supply process electrochemical capacitor C86 and ceramic condenser C88 filtering, and negative supply is through electrochemical capacitor C87 and ceramic condenser C89 filtering.

Claims

1. a Signal Spacing is changed output module, comprised that bus communication processing module, single-chip microcomputer, digital signal are isolated module, power supply is isolated module, digital-to-analog conversion module and signal output conditioning module, it is characterized in that, described bus communication is handled module and is included a Transistor-Transistor Logic level commentaries on classics RS-232 level chip and a Transistor-Transistor Logic level commentaries on classics RS-485 level chip, and described digital signal is isolated module and is made up of four high speed optoelectronics coupling isolating chips; Described power supply is isolated module and is comprised an overvoltage and anti-reverse holding circuit, filtering circuit and a step-down switching mu balanced circuit and a DC-DC isolation module power supply; Described digital-to-analog conversion module is made up of analog-digital chip and gate circuit chip.

2. according to the described Signal Spacing conversion of claim 1 output module, it is characterized in that, overvoltage and anti-reverse holding circuit that described power supply is isolated module comprise an anti-reverse protection diode and a TVS pipe, described filtering circuit comprises electrochemical capacitor and ceramic condenser, and described electrochemical capacitor and ceramic condenser are that parallel connection is linked in the circuit; Described step-down switching mu balanced circuit comprises lowering and stabilizing blood pressure chip, diode, inductance, inductance capacitance.

3. according to the described Signal Spacing conversion of claim 1 output module, it is characterized in that what the Physical layer of described bus communication processing module adopted is RS-232 or RS-485 agreement.