CN86104644A - The programmable logic controller system that is used for hazardous environment - Google Patents

Abstract

The programmable logic controller system that is used for hazardous environment has the unit 30 of 10, one microprocessor of a microprocessor logic controller and variable memory.This element is connected with controller, with test and update routine.Program after the test is sent in the outer non-volatile memory of hazardous environment, then this memory is taken in the hazardous environment, is installed on the controller, to make routine operation.This just allows before program is deposited non-volatile memory, test procedure, update routine on controller.Between said units and any one temporary location and the controller, by opto-isolater communication and employing serial data transmission.

Description

The programmable logic controller system that is used for hazardous environment

The present invention relates to programmable logic controller (PLC), for example, be applicable to the programmable logic controller (PLC) of industrial premises.Now general, Programmable Logic Controller is by known.Yet the present invention proposes a kind of hazardous environment that is applicable to for example the programmable logic controller system in the place of explosion danger.

The present invention proposes a kind of system that connects some unit, and it comprises:

(1) first module, it is a controller that is applicable to hazardous environment, it comprises that one is subjected to store programmed control, and can assembles the microprocessor of the non-volatile memory of this program of storage.

Unit (2) second, it comprises a variable type memory, it allows to change selectively the data that exist in each storage address under the situation of the full content of not removing this memory.

This controller and above-mentioned Unit second are designed to link together, and this controller is placed in the hazardous environment at least, and the program that this controller is stored in by (at least when initial) in the variable type memory of above-mentioned Unit second is controlled.Then, program is sent to the non-volatile memory that is assemblied on the controller.

The present invention can pack in the program that is verified and be installed in non-volatile memory on the controller and allow before carrying out routine operation the user just check on the controller and the program of using under hazardous environment, does not need trace routine after program writes non-volatile memory.Advantage of the present invention is to allow user's modification and check the program of just working again in hazardous environment.

Before the microprocessor operation of controller, the program of storing in the variable type memory of above-mentioned Unit second can copy in the easy mistake memory of controller.Controller can assemble a non-volatile memory, also can assemble one and easily lose memory (program copies to this memory from Unit second).

Be equipped with the keyboard that energy is used at hazardous environment preferably for controller and/or Unit second, so that revise the program in the variable type memory of Unit second.

Unit second is the portable unit that suitable hazardous environment uses preferably, no matter whether it is of portable form, Unit second preferably includes a microprocessor.

Portable Unit second can directly be connected with cable by electrical cnnector with being connected of controller, and this moment, the both was placed in the hazardous environment.

Another kind of connection can connect by a middle device that is also placed in the hazardous environment.At this moment this middle device can be used for the operation of supervisory control device and the supervisory control device factory under operating, and this monitoring unit can be placed on the place away from controller.

Also have a kind of connection to can be used to extend to hazardous environment inside from the outside of hazardous environment.If when Unit second can not be portable, this connection often was used.

" variable type memory " comprises easy mistake memory, and it preferably has the random access memory (RAM) (RAM) of standby power supply, with anti-lost storage content.

When the program in the modifiable memory is satisfied, it can be passed to a non-volatile memory, then this non-volatile memory is assemblied on the controller so that controller thus program control.Sending non-volatile memory to carries out beyond hazardous environment usually.

Non-volatile memory is semiconductor memory normally, just can preserve the storage content under without any the situation of power supply, and this memory can be programable read only memory (EPROM), if do not wipe the full content of memory, its content can not disappear.

What can replace EPROM is electricity variable readable memory (EAROM), can change single memory address, but the speed of rewriting is slower than the speed of reading a memory address or write among the RAM.

Usually, controller can not change the content of non-volatile storage.

Be more preferably, native system is included in outside the hazardous environment program is sent to the device that non-volatile memory is used from portable unit.This device preferably or comprise an EPROM programmer (also being the EPROM solidification device sometimes).

In order to give the EPROM convey program, preferably portable unit directly is connected with EPROM programmer.This EPROM programmer also can be used for duplicating this program, and these versions are used as backup in EPROM.It can also carry out other function, such as output is provided to printer so that the hard copy of production process table or this program copied to other peripherals by industry standard interface or main frame gets on.

Be more preferably, portable unit has battery supply, when controller is connected with portable unit, connects by one or more opto-isolaters best, to keep electric insulation.

Another advantage is, portable Unit second is a matching unit, and it comprises a keyboard, a display and a microprocessor, no matter whether portable unit is connected with controller, it can both load or changes memory.

In the arrangement of the best, controller and Unit second are to arrange like this and operation (as above summary) is sent to RAM the controller to a program from the variable memory of above-mentioned Unit second.After this, the microprocessor of controller just moves under the control of this program that is transmitted.

Preferably program is sent to controller from Unit second with such speed, promptly the clock speed of normal operation (at microprocessor and deposit between the memory of microprocessor executive routine the speed during direct communication) is wanted slow speed (must be accompanied by low frequency) transmission with than the microprocessor direct access memory of controller the time.The pulse that transmits is probably than longer with the pulse of normal clock speed direct access.

This transmission at a slow speed can be by being formed with the transmission of a kind of pulsed frequency also low frequency of clock frequency of the microprocessor in controller and the Unit second (promptly than).This transmission can realize by signal exchange between two unit, but often really not so, also can be serial transmission.

Transmit at a slow speed and can realize choosing further optoisolator,, between the conductor of two circuit, just can provide bigger physical space, whereby they are separated owing to chosen the distance of optoisolator.

In order further to explain the present invention, now in conjunction with following description of drawings several embodiments of the present invention by example:

Fig. 1 illustrates the each several part of system,

Fig. 2 and Fig. 3 illustrate a part of circuit of distinguishing slightly system.

Consult Fig. 1 earlier, programmable logic controller (PLC) 10 is placed among a kind of hazardous environment (may be the colliery).

According to the requirement of wanting Shi Yong Armor dress cable in explosive area, controller has been equipped with the connector (as 12,14) of multichannel input and multichannel output with Lian Jie Armor dress cable.

Controller has considerable I/O (I/O) passage, and is equipped with some interchangeable circuit boards, so that these passages and input and output attachment unit interface, these circuit boards have three kinds, and a kind of circuit board is 16 tunnel inputs and I/O channel interface.Other two kinds of circuit boards all are with controller and output channel sensor interface, and wherein a kind of circuit board provides direct drive for 16 tunnel outputs under the instruction of the microprocessor of controller.And another kind of electric current plate under the situation of band output load condition monitoring, provides direct drive for 8 tunnel outputs under the instruction of the microprocessor of controller.

It is applicable to the explosive area to controller by power supply unit 16a() power supply, this element also is the circuit board power supply of the input interface of the sensor., each output circuit plate also needs one, two additional supply unit, and each 16 channel circuit board has two circuit that work in 8 passages, and each 8 channel circuit board has two circuit that work in 4 passages.These circuit mutual insulating on electric, also with other circuit insulation of controller, each circuit design Cheng Youyi independently power supply unit 16b power supply.Use many power supply units and electric insulation each other, satisfied the requirement in explosive area.The input signal of the output driving circuit of these electric insulations transmits through optoisolator.

In controller, there is the plan of a microprocessor (CPU), one nonvolatile memory permanent assembling, the deposit operation system and a permanent assembling when program run, to be used as the RAM that working storage uses and deposits some variablees and a storehouse.In addition, controller also comprises one for connecting the connector 20 of detachable circuit board 22 usefulness.

In order to use selectively, two kinds of circuit boards are provided, a kind of plate 22a has RAM23, it can be the non-volatile memory of EPROM43 that another kind of circuit board 22b has one at least, no matter the assembling the sort of plate, memory in the storage conversion of controller microprocessor, occupy same space, plate 22a and 22b preferably identical or similar as far as possible.

There are a keyboard 32, liquid crystal (LCD) display 34, an inner microprocessor (CPU), a non-volatile memory and a RAM35 who has watchdog routine, ickel-cadmium cell 36 power supplies that this element is filled again by an independent charger 37 in portable second unit 30.Thereby this element is fully supporting.The user of this system control program of a plan of can packing into by controller 10 operation.The user can use the keyboard 32 of portable unit, pack into the RAM35 of portable unit of this control program.Then, the user is by keyboard 32 input instructions the time, with display 34 scrutiny programs.Portable unit 30 also has one or more port 38, can be connected with the many peripherals that have an EPROM programmer 42, and so just can pack program into is contained in EPROM on the circuit board 22b.

EPROM formatter 42 and battery charger 37 such peripherals never enter the explosive area.

Portable unit 30 will be put into the explosive area, links to each other with controller 10 by port 39, connects by optoisolator when these two unit connect.When data transmission, make electrical isolation between these two unit with optoisolator.Optoisolator both can be placed in the controller, also can be placed in the portable unit, and dual mode is all desirable.

Select for use optoisolator to present physically separation between two circuit, this separation is enough to satisfy the technical requirement of using in the explosive area.

When unit 10,30 connects in the explosive area, instruction of available keyboard 32 inputs, start a program (it is kept among the RAM35 of portable unit and is copied among the RAM23 on the controller circuit board 22a), then, this program is carried out by the microprocessor of controller.

Usage is as follows:

Designated program is packed among the RAM35 by keyboard or other peripherals such as EPROM programmer.Then portable unit 30 is taken to the explosive area of controller 10 being installed and RAM plate 22a being housed, in the RAM23 of program copy to the plate 22a, (promptly moving this program by controller checks to check designated program then, yet in this stage, the controller function system also allows by the direct input instruction of the keyboard of portable unit).

In the inspection period, can revise the program among the RAM35.At the scene, if necessary, can be in RAM23, to check this program the program copy of having revised.When program has arrived final version, unit 30 is taken out from the explosive area, receive on the EPROM programmer 42, program copy to EPROM43, EPROM43 brings the explosive area into, and changes plate 22a after being contained on the plate 22b, so just the final version of user's program as director demon, this program is kept among the EPROM of plate 22b.

Should pay attention to providing the change of program can utilize this system more fully, can also make full use of the matching performance of portable unit like this at the scene, explosive area.

The program of controller 10 and portable unit 30 and their operating system is design like this, promptly any one microprocessor all can not be from the memory of another unit direct access.Apparently, is a kind of very suitable technology by the interface between two unit to the direct access of memory, yet, we have found that and to avoid this technology, no longer design these unit, but, copy in the memory of controller and go the program design among the RAM35 must be utilized the method for serial data transmission.Slower transfer rate allows to use optoisolator at a slow speed, and making has bigger actual separation between the circuit.

RAM35 is preferably cmos type, because this RAM is low in energy consumption.CMOS type RAM is also preferably adopted in other places in system.In fact, all chips (comprising microprocessor) all are CMOS(complementary type Metal-oxide-semicondutors) type.

Portable unit 30 as shown in the figure, and two independently port 38 and one ports 39 are independently arranged, and port is the least possible, might be only with a port with three port functions.

Portable unit 30 can have a slice and RAM35 to divide the RAM chip of opening to be used for depositing some variablees and a storehouse.In other words, this usefulness is done in the address of some in RAM35.

Interchangeable circuit board 22a, 22b except interchangeable RAM and non-volatile memory are housed, preferably lack dress and even do not adorn parts.; can load onto additional parts easily on it; these parts are copied the sum of the circuit board that needs with the minimizing controller on two plates, so these circuit boards can have the operating system program that deposits controller in, the ROM of address decoding logic and the chip of microprocessor.

In this development phase, exist program among the RAM35 can expect the point of interruption of taking measures to realize single-step operation, resting on some appointments, or other diagnostic functions (these functions disappeared before copying to EPROM immediately).Circuit board 22a can have the hardware that single-step operation is used, but circuit board 22b does not need this function, can save.

Fig. 2 and system shown in Figure 3 can be contained in RAM23 or non-volatile memory (as EPROM43) on the labour-saving socket of controller except circuit board 22a, the 22b that exchanges is not used to.

Fig. 2 illustrates a part of circuit of controller.Another part circuit (as time clock take place, the connection of the memory of conversion input and output) can be microprocessor microcontroller architecture, general.

As shown in Figure 2, controller 10 comprises that one is connected with address bus A with data bus D and removes three topmost address wires 51 in the microprocessor 50(bus, outside 52 and 53, all the other each lines do not draw), ROM54(ROM54 who links to each other with address bus with data bus operating system of leaving microprocessor in is watchdog routine) one deposit the RAM55 of some variablees and a storehouse, labour-saving socket 56(as working storage and be used for laying a sheet RAM chip 23 or non-volatile memory such as EPROM chip 43), as shown in the figure.Article two, topmost address wire 52,53 link to each other with one 2/4 coding chip 58, this chip also selects (CS) pin to link to each other with the chip of ROM54 and RAM55, and this chip also links to each other with that terminals of " accepting chip selection (CS) pin line of RAM23 or non-volatile memory 43 " on the socket 56.

The wiring of coding chip has determined that it is with three lines in four lines after the decoding that microprocessor is alternately chosen memory, chooses memory sheet and working storage RAM55 in ROM54, the socket continuously.A remaining line is used for storing the I/O of conversion.

Those terminals of reading " accepting the exportable pin line of RAM23 or EPROM43 " on exportable (DE) pin and socket 56 that (RD) control line is connected to RAM chip 55 from microprocessor.

In order to make socket can accept the line of RAM23 chip or EPROM chip 43, circuit should be designed to adopt chip-shaped circuit, and RAM has the various functions of being implemented by identical pin with the EPROM chip.Usually the EPROM and the RAM chip of commercial identical memory capacity all have a lot of function (as: data line, address wire and chip are selected), and implement its function on corresponding pin.

With regard to pin, be that different, socket 56 line end correspondingly can come wiring by interlock selector switch 60 for the pin function of RAM and EPROM.

In an example shown, when switch during at lower position, pin 61 links to each other with (WR) control line of writing of microprocessor.When switch during in the high position, it links to each other with address wire 51.This just can be applicable to RAM and EPROM respectively.

Correspondingly, another pin 62 links to each other with address wire 51 or power source voltage Vcc.

Though the wiring of not drawing socket 56, but the on line principle of several terminals by selector switch also can be used for making socket to accept the memory that multicapacity more varies in size, as 8 8K and 8 32K, two kinds of dual inline type (DIL) socket bags (it has under any circumstance, many pins that function is identical) that all are applicable to 28 pin.

Being suitable for the EPROM chip of commercial memory chip 27C64 and 27C256 and 6264 and 65256 RAM chip is exactly example.

RAM55 has a rechargeable standby power supply (not having picture), so that preserve the content of its storage when power fail, primary power cource charges to standby power supply automatically by a diode, in order to keep very limited standby power supply.When the primary power cource fault, do not select RAM55 for use.This will be plugged between the chip selection pin of code translator 58 and RAM55 by a three-state buffer 64() guarantee that when impact damper was powered by standby power supply, " starting " pin of impact damper linked to each other with the primary power cource voltage vcc.If the primary power cource fault, then impact damper is not just worked, and it is output as high impedance, and by resistance 65 backup power source voltage V _BVAdd.

Fig. 3 illustrates the circuit that portable unit uses, the same with controller, portable unit 30 have 70 1 of microprocessor to link to each other with data bus D, address bus A and 71,72,73 and ROM74(Fig. 3 of deposit operation system in three the topmost address wire labels that only draw be 71,72,73), the part of a RAM76(RAM who also links to each other with address bus with data bus is as working storage, another part is used for storing user's program), that link to each other with " chip selection " pin, 2 lines/4 line code translators 78.Microprocessor 70 can alternately be selected rom memory 74 and RAM76, and this selection is to finish by two continuous selection wires in four lines after the decoding.

Portable unit have among a keyboard 32 and a display 34(Fig. 3 do not draw), they are connected with the input/output end port of microprocessor 70.If microprocessor used it not have such input/output end port in the past, keyboard will link to each other with microprocessor by a universal peripheral interface adapter with display.

Fig. 2 and Fig. 3 also show the method that is connected between this portable unit and the controller.

The pin that microprocessor 50,70 all promising serial data input and output are used (the serial data input and output of other microprocessor can link to each other with microprocessor, independently universal asynchronous receiver/transmitter (UART) (UART) provides) by one.

Portable unit comprises a pair of optoisolator 80,82.The serial data of microprocessor 70 output 84 links to each other with the diode of isolator 80, and the transistor AND gate serial input 86 of isolator 82 is continuous.

The transistor of the diode of isolator 82 and isolator 80 by 4 pins of a socket 90 to the controller 10 weak point and the jumper cable of flexible is connected on 4 pins of socket 88, socket 90 is connected to the power supply of controller and the serial data input and output pin of microprocessor 50, when connecting by jumper cable with convenient socket 88,90, the serial output 94 of microprocessor 50 links to each other with the serial input 86 of microprocessor 70 by isolator 80, and serial output 84 links to each other with the input 96 of microprocessor 50 by isolator 82.

Like this wiring can be between portable unit 30 and controller 10 without any under the condition that is connected on directly electric, between two microprocessor, carry out the transmission and the signal exchange of serial data.

Being connected of " advancing " of input and output 84,86,94,96 and " going out " all will be by amplifying impact damper 98.The pin of socket 88 and socket 90 respective pin are represented with label 1,2,4,5.

The transfer rate of serial data is per second 500 bits or lower, and the clock frequency of microprocessor can be 1 megahertz or higher.Therefore, sustainable hundreds of the clock period of each pulse of serial link.

Microprocessor 50 has a pin one 00 of linking the input/output end port of switch 102, and switch 102 can be controlled pin 100 and connect power source voltage Vcc or ground connection.

If this switch is to put controller 10 in " free running mode " or " debud mode ".During energized, operating system begins with initial value, then, and test pin 100 and corresponding each shunt.If switch 102 places " free running mode ", microprocessor is then carried out any program in the memory that is contained on the socket 56.If switch 102 places " debud mode ", operating system is then waited for from portable unit 30 and being sent, by an instruction of serial link transmission.

Fig. 2 is very similar to the system that Fig. 1 is adopted with the system that Fig. 3 is adopted.

After a program was packed into by the keyboard of portable unit, this element just was connected on the controller 10.Socket 56 planted agents of controller RAM chip 23 is housed in this stage, switch 102 should place " debud mode ", and this program is on RAM76 copies to RAM23 the socket 54.The instruction of finishing this cover program should be put into the operating system of two microprocessor 50,70, send instruction and must import this duplicating style by the keyboard of portable unit, and by serial data link transmission between portable unit and the controller, next step is to identify designated program.If desired, the program in the RAM76 of portable unit can change, and version replication is after changing gone up and tested to RAM23.This can repeat to do.When testing under " debud mode ", instruction can be imported by the keyboard of portable unit, and is transferred to controller through serial link.For example, may send the procedure operation of an instruction, or begin operation at a certain specified point of program according to single-step operation.The instruction of carrying out such program should be placed in the operating system of microprocessor 50.

When program when being satisfactory, portable unit then is not switched on, and is with EPROM programmer 42.EPROM programmer 42 is to be used for program copy to EPROM43.In order to transmit the serial data in the EPROM programmer, the connection of EPROM programmer 42 can realize by programmable device and being connected of socket 88.

EPROM43 after the curing is installed into controller 10, and is contained in the socket 56, to replace RAM23.In the memory of microprocessor 50 was replaced, EPROM43 occupied identical space with RAM23.

Because being used as " working storage ", the part of RAM76 uses, if the capacity of RAM76 is big unlike above two kinds of memories, and the program that the user packs into this RAM that can not pack into, can not pack into RAM23 or EPROM43, in fact, capacity is not strict restriction.

Claims (14)

1, a kind of system that connects some unit, it comprises:

(1) first module, it is a controller that is suitable for hazardous environment, it comprises that one is subjected to oneself to store programmed control, also can assemble a microprocessor that stores the non-volatile memory of this program, is characterized in that also having in this system:

Unit (2) second, it comprises a variable type memory, it allows under the situation of the full content of not removing this memory, changes the data that exist in each storage address selectively,

This controller and above-mentioned Unit second are designed to link together, and this controller is placed in the hazardous environment at least, and this controller is controlled by the program in the modifiable memory that is stored in above-mentioned Unit second.

2, system according to claim 1 is characterized in that it also comprises: a program is sent to the device that a non-volatile memory is used from the variable type memory of above-mentioned Unit second.

3, system according to claim 2 is characterized in that: said apparatus is an EPROM programmer.

4, according to any one the described system in the aforesaid right requirement, it is characterized in that: the connection between this controller and above-mentioned Unit second allows communication, and the two keeps electric insulation mutually.

5, system according to claim 1 is characterized in that it also comprises an optional equipment that is applicable to hazardous environment, and is connected by above-mentioned optional equipment between controller and above-mentioned Unit second.

6, system according to claim 1 is characterized in that having at least one to have the keyboard that an energy uses under hazardous environment in above-mentioned controller and the above-mentioned Unit second, so that update routine.

7, system according to claim 1 is characterized in that Unit second comprises a microprocessor.

8, system according to claim 1 is characterized in that above-mentioned Unit second is a portable unit that is applicable to hazardous environment.

9, system according to claim 8, it is characterized in that this portable unit is a kind of supporting unit, it comprises a keyboard, a display and a microprocessor, no matter whether this portable unit be connected with controller, it can both load or changes the above-mentioned memory of this portable unit.

10, according to Claim 8 or the described system of claim 9, it is characterized in that this portable unit has between a battery supply and controller and the portable unit by one or more optoisolators connections, so that controller and portable unit keep electric insulation.

11, system according to claim 1, it is characterized in that when being that controller is when being placed on hazardous environment at least, the program that is stored in the variable memory of above-mentioned Unit second will be sent among the RAM of controller, because after this controller is by the said procedure control among the above-mentioned above-mentioned RAM that is sent to controller, controller is arranged alternately by the program among the above-mentioned RAM or by the programmed control that was sent to before above-mentioned memory is installed on the controller in the above-mentioned nonvolatile memory.

12, system according to claim 11, it is characterized in that between controller and above-mentioned Unit second, being connected by one or more optoisolators, program is sent among the above-mentioned RAM, transmission speed than at microprocessor and the frequency when depositing direct communication between the memory of the program that microprocessor carrying out low.

13,, it is characterized in that this controller arranges to such an extent that replacedly load onto above-mentioned RAM or above-mentioned non-volatile memory according to claim 11 or 12 described systems.

14, require according to aforesaid right in the described system of any one claim, wherein in above-mentioned Unit second and the communication between this controller when they link together, be to adopt serial data transmission.

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