CN2164072Y - STD bus multifunction module - Google Patents

Abstract

The utility model relates to an STD bus multifunction template, which adopts MCS-96 series single chip computer. A standard size circuit board is provided with two thermal resistance temperature transducers and two I/V converters, and the output is a D/A converter with eight bits and a full double interface IRS-485. Light barriers are arranged between the signals all above and a mainframe. A keyboard and LCD are directly connected with an interface 82C55 under the support of software. The multifunctional CPU plate of the utility model has the advantages of low cost and perfect performance, which is suitable for being used as a lower computer of a distributing control system or a single loop controller.

Description

STD bus multifunction module

The utility model relates to a kind of MCS-96 series STD bus formula multifunction formboard, belongs to the field of computer technology that is used for industrial control process.

Though existing MCS-96 series STD bus CPU template also possesses the analog quantity input function, but its input signal is non-isolation voltage signal, as forming industrial computer system with this template, the user must expand a large amount of function terminal strips, as isolated transmitter terminal strip or I/V end of convert daughter board etc., because if adopt routine techniques is impossible hold these functional parts on standard-sized wiring board, so just certainly will cause custom system line complexity, structure is too fat to move, the failure rate height, the installation and maintenance difficulty, thus it is little to make the MCS-96 single-chip microcomputer lose its volume, advantages such as function is strong.Adopt extended function terminal strip method to come the composition system on the other hand, relatively be fit to big system, mini system and the single loop control device used always for the industry control process, this combined method makes the many functions on the CPU board seem unnecessary again, as original non-isolation analog quantity input and power drive chip etc.Above-mentioned shortcoming causes existing MCS-96 series CPU board at mini system, and single loop control aspect adaptability is very poor.

The purpose of this utility model is to disclose a kind of versatility and MCS-96 series STD bus formula CPU board with better function, and this multifunction formboard is particularly suitable as the slave computer or the single-loop controller of collecting and distributing control system.

It is to realize like this that the utility model has task, a kind of MCS-96 series STD bus formula CPU template, its output comprises PWM mode D/A delivery outlet and RS-485 serial line interface at least, its importation is characterised in that and is provided with resistance and temperature transmitter and I/V converter, this transmitter is connected with described MCS-96 singlechip CPU chip input channel through photoisolator with converter, its keyboard is characterized as keyboard scanning circuit with display interface and directly is connected with the interface chip of CPU with the LCD display control circuit, shows that control obtains the support of a timesharing output timing program.

Taken up space on the line by dwindling a large amount of resistance of temperature transmitter part, the utility model is arranged setting with the used different resistance resistance of this part in the circuit board with the integrated resistor mode of dual-in-line, and can effectively reduce institute and take up space,

Getable main invention effect is after adopting technique scheme

（1）。Removed parts unnecessary on the original template such as power drive chip, not with light every the analog quantity input block and be used for keyboard and the latch of liquid-crystal display section, decoder chip, so both vacateed the space of wiring board, simplified circuit again, created condition for strengthening template function.

(2), the integrated inserting mode of discrete resistance can make eight discrete type resistance are installed on a standard 16 pin integrated circuit sockets, makes a large amount of resistance of resistance and temperature transmitter circuit part to concentrate distribution is set, reduced institute effectively and taken up space.

(3), the band light every practical IO interface, a this CPU template is exactly a high-performance Industrial Control Computer, this STD bus formula template cost is low, low in energy consumption, the speed height, antijamming capability is strong, is fit to most of industry spot single loops controls or as the slave computer of collecting and distributing control system.

With regard to drawings and Examples, the utility model is specified below.

Fig. 1 is that template is arranged synoptic diagram.

Fig. 2 is a circuit block diagram.

Fig. 3 is a thermal resistance transmitter circuit schematic diagram.

Fig. 4 is the integrated grafting synoptic diagram of discrete type resistance.

Fig. 5 is the current converter circuit schematic diagram.

Fig. 6 is keyboard and LCD interface circuit.

Fig. 7 is a software sequential block diagram.

Fig. 1 is a STD bus formula multifunction formboard master unit Pareto diagram, this die shape is 165 * 114 standard sizes, integrated circuit U1-U9 chip on the plate is respectively CPU, latch, code translator, EPROM, RAM * 2, interface chip, logic chip and monitoring voltage chip, accurate adjustable potentiometer W1-W7 are used for input range and regulate zero point, and JC1 and JC2 are two jumper wire devices, J1-J5 is five connectors, be used to connect LCD, keyboard, output, input and power supply.Reserve battery V can give RAM U5 or U6 power supply, to preserve the program or the data of U5 and U6 internal memory.The main chip model is a U1:MCS-96 series, as 8098, and U7:82C55, U8:74HC04, U9:TL7705.

Fig. 2 is a circuit block diagram; computer core portion C PU chip MCS-98 is connected with bus STDBUS; monitoring voltage chip TL7785 suppresses the influence of the various noises of supply voltage to main frame, and the EPROM of 8K and the RAM of 16K are as storer, and reserve battery V makes RAM support write-protect.The RS-232 interface of cpu chip MCS-98 is connected every full duplex RS-485 serial port with a band light, and its RXD signal input current is not more than 0.5ma, and the Txd output current is not less than 200ma, does not add any driving stage, just can directly use the twisted-pair feeder networking.The width modulation mouth PWM of MCS-98 is connected every D/A converter with eight bit strip light, and 0-10ma is provided output.The input channel ACH4 of MCS-98 is connected two-way resistance and temperature transmitter pt100-1 and pt100-2 with ACH5, ACH6 is connected two-way 0-10ma current converter I-1 and I-2 with ACH7.MCS-98 also directly is connected with LCD LCD and industrial keyboard JP through interface chip 82C55.From above-mentioned functions as can be seen, this multifunction formboard, a plate is exactly a high-performance industrial computer.

The thermal resistance transmitter circuit is seen Fig. 3.Thermal resistance Rt and resistance R 0-R constitute bridge circuit, provide-Usr ,+the Usr differential wave, after the data amplifier that A1, A2, three grades of amplifiers of A3 are formed amplifies, by passage ACH4 or the ACH5 of photoisolator G1 input MCS-98CPU.At the input resistance R8 two ends of amplifier A3 and connect a nonlinearity correction circuit of forming by diode D and resistance R 9.This circuit guarantees that omnidistance transfer linearity change is not less than 0.3%.

On STD bus formula template the thermal resistance transmitter is set directly, solve a difficulty is to settle a fairly large number of resistance in the circuit board.The scheme that the utility model adopts is that these resistance are formed the dual-in-line integrated resistor, as shown in Figure 4, can on one 16 pin integrated circuit socket eight separate type resistance be installed like this.Eight resistance of R0-R7 are the resistance of eight correspondences in Fig. 3 circuit among the figure.

Fig. 5 is current converter circuit figure.Resistance R 11, R12 and R13 form floating vagabond current fan-in network, and R12 is last also and meet filter capacitor C, to suppress interference.Signal R12 goes up and takes out, and adds to the A4 end of oppisite phase, two photoisolator G2 of amplifier A4 output terminal serial connection and G3, wherein G2 and resistance R 14 constitute the backfeed loop of A4, G3 provides output signal, and two light can reach the satisfied precision and the linearity every the non-linear mutual compensation of device.

In keyboard shown in Figure 6 and LCD interface circuit, the PA mouth of interface chip 82C55 is connected with LCD through socket J1 with PC0-PC2, and wherein PA is defined as bidirectional interface, carries data or order, PC0-PC2 is a control line, is connected with RS, R/W and the sheet choosing end of LCD respectively.Keyboard socket is J2, and the PB mouth of 82C55 is connected with keyboard through J2 with PC3-PC6, and wherein PC3-PC6 is a line, and PB0-PB7 is an alignment, can use for the industrial keyboard that is no more than 32 keys.A scanning sequence can read in keyboard signal.

The software that replaces the hardware time order interface circuit is mainly realized by the corresponding bitline state of 82C55.Software is made of two subroutines, and the one, read the engaged line subroutine, the 2nd, write data or order subroutine, flow chart is seen Fig. 7.When reading the engaged line program and beginning 82C55 with the A mouth be decided to be into, the C mouth is read engaged line repeatedly for going out, and returns when D7=0, enters and writes a program.A mouth and C mouth all are defined as out when writing a program initialization, send command word to the C mouth earlier, then with data or order the mouth to A, then send a square wave to sheet choosing end, rising edge be the sheet choosing effectively, it is invalid that negative edge is that sheet selects, and finishes once to show.

This high-performance template can be used as single card microcomputer and uses, and does not need to insert motherboard, and external power supply can directly be welded on the power input line of template.As doing with the saturated vapour is the temperature controller of system of heating medium when using, and connects power supply, LCD, and keyboard and thermal resistance, pneumatic-to-current converter, and after adding PID regulation and control module and parameter setting module, can realize industry control.Measure temperature with the Pt100 thermal resistance, after subtracting each other to fixed temperature, obtain error signal, calculate through the PID regulation and control, by D/A transducer output 0-10ma, current signal is added on pneumatic-to-current converter, and the control pneumatic control valve is done closed-loop control.

Because the restriction of STD bus template size, the I/O mouth quantity that such scheme provided is many not enough, and such as not establishing parallel printer, the switching value input-output line waits very little.For reaching the purpose that increases I/O, only need do some accommodation, can realize.Method is to remove golden finger, changes common interface chip into, as 74LS245,74LS244 etc., under the situation that does not increase coding chip, can obtain 32 road I/O mouths, so just becomes the veneer industrial computer of a more perfect functions.

Claims (6)

1, a kind of STD bus formula multifunction formboard, CPU is the MCS-96 series monolithic, is provided with PWM mode D/A output and RS-485 serial line interface mouth, it is characterized in that:

A, input stage are provided with resistance and temperature transmitter and I/V converter, all are connected with the main frame input channel through photoisolator;

B, keyboard and LCD control circuit directly are connected with the interface chip 82C55 of CPU, and LCD shows that control obtains the support of timesharing output timing program.

2, by the described STD bus formula of claim 1 multifunction formboard, it is characterized in that the resistance component of described resistance and temperature transmitter is arranged setting in the circuit board in dual-in-line integrated form resistance device mode.

3, by claim 1 or 2 described STD bus formula multifunction formboards, the final stage input resistance R8 that it is characterized in that the data amplifying circuit of described thermal resistance transmitter goes up and connects one and is connected in series the nonlinearity correction circuit that constitutes by diode D with resistance R 9.

4, by claim 1 or 2 described STD bus formula multifunction formboards, the input circuit that it is characterized in that described I/V converter is provided with a resistance R 11, the network that R12 and R13 serial connection form, interlaminated resistance R12 goes up and connects filter capacitor C, constitute and import floatingly, signal takes out from R12, input amplifier A4.

5, by the described STD bus formula of claim 1 multifunction formboard, it is characterized in that described LCD display is connected with PC0-PC2 with the PA mouth of 82C55 interface chip, wherein the PA mouth is a bidirectional interface, PC0-PC2 respectively with the RS of LCD end, R/W end and sheet choosing end connect, and the timesharing output timing program of supporting comprises reads engaged line subroutine and write data subroutine, when entering back one subroutine, PA, PC mouth all are decided to be, and program is followed successively by

Send command word,

Write data to the PA mouth,

The sheet choosing is effective,

Sheet selects invalid;

Data on the PA mouth are effectively sent to LCD the back in the sheet choosing.

6, by the described STD bus formula of claim 1 multifunction formboard, it is characterized in that described keyboard is connected with PC3-PC7 with the PB mouth of 82C55 interface chip.

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