CONTENTS. 1.0 Introduction Description of the Circuit Installation Connection of Power Supply 4

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1 1 CONTENTS PAGE NO 1.0 Introduction Description of the Circuit Installation Connection of Power Supply Connection of Output Signals to Relay Contacts Interfacing to ESA Trainers Demonstration Examples Demonstration Program for MPS 85-3 Trainer Demonstration Program for ESA 85-2 Trainer Demonstration Program for ESA 80 Trainer Demonstration Program for ESA 31 Trainer Demonstration Program for ESA 68K Trainer Demonstration Program for ESA 86/88-2 Trainer Application Notes Power Supply Monitor Timed Bell Circuit Absolute Zero Level in TTL Logic 17 Appendix A : Component Layout Diagram Appendix B : Schematic Diagram Appendix C : Connector Details

2 2 1.0 INTRODUCTION Electro Systems Associates Pvt Ltd manufactures a variety of microprocessor trainers, development/debugging tools and also microcomputer development systems useful for educational institutions and research and development laboratories. The relay output card is a general purpose interface for microprocessor based systems, PC compatibles or any other electronic control systems where absolute electrical isolation between the system and external contacts is required for the safe operation of the system. The relay output card allows the user to connect a system to control 24 relays. It provides convenient interface for various applications like programmable logic control, industrial automation etc. RELAY OUTPUT CARD SPECIFICATIONS Input data lines : 24 Signal input level Mode of relay contacts Maximum switched voltage Maximum carry current Power requirements System requirement : TTL compatible : SPDT : 110V : 1.5 Amp per contact : +12V DC at 500 ma maximum : a. Any microprocessor based system with TTL output ports b. Any PC compatible system c. Any other system with TTL output ports

3 3 2.0 DESCRIPTION OF THE CIRCUIT Please refer to the schematics of this interface presented in appendix B. This interface consists of 24 relays each operating at +12V DC. One end of the relay coil is connected to +12V and the other end to the output of an inverter buffer (ULN 2003). All the 24 relays follow similar connections. The relay contacts are brought to screw terminals (A0,B0,C0,A1,B1,..etc) at connector J2. All the input lines of the inverter buffer are brought to a 26 pin male connector J1 on one edge of the card. When the input to an inverter buffer is high, it's output is low and the relay coil connected to this inverter gets activated. When the input to an inverter buffer is low, it's output is high and the relay coil is not activated. The inductive coupling between relay coil and contacts provides electrical isolation between the controlling system and the contacts. 3.0 INSTALLATION The relay output card is supplied as a package containing following units. Relay output card User's manual The interface module has a 26-pin connector at one edge of the card. This is used for connecting the interface to the trainer with a flat cable connector set. Table 3-1 shows the connector on various trainers to which this interface can be connected. Some trainers have two connectors and either may be used for connecting this interface. The demonstration programs presented in this manual assumes that the interface is connected to connectors shown in column A. If the connector shown in column B is used, then user has to change the port addresses appropriately. User may refer to the component layout diagrams of respective ESA trainers to locate the connectors mentioned here. TABLE-3.1 MICROPROCESSOR A B TRAINER MPS85-3 J2 J1 ESA85-2 J2 J1 ESA-80 J2 J1 ESA-65 P4 ESA-68K P3 P4 ESA 68K-2 J2 J1 ESA 68-2 J1 J6

4 4 ESA 196 J1 J2 ESA-31 J2 J1 ESA-51 J10 J7 ESA-51E J5 J3 ESA-86/88-2 J4 J5 ESA-86/88-3 J8 J9 ESA-86/88E J4 J6 3.1 CONNECTION OF POWER SUPPLY The interface requires a power supply of +12V DC at 500 ma maximum. If the user system has provision to feed +12V to pin 25 of the connector J1 on the interface, a jumper must be connected at JP1. As shipped from the factory, JP1 is kept open. If the user system does not have the provision to feed +12V, a two pin connector J3 provided on the interface can be used to connect the power supply. Make sure that it is connected with proper polarity. Please refer to the layout and schematic diagrams for locating connector J1, jumper JP1 and the two pin connector J3. When separate power supplies are used, their negative terminals should be shorted together. A power switch is provided on the interface to facilitate switching-on and off the power to the interface without affecting the power to the system. 3.2 CONNECTION OF OUTPUT SIGNALS TO RELAY CONTACTS There are three lines coming from a relay that are terminated at screw terminals. (eg. A0,B0 and C0.) When the relay is not activated, connection exists between A0 and C0 (normally closed). When the relay is activated, connection changes and exists between B0 and C0 (normally open). For connecting signals to relay contacts, Loose the screws on the terminations. Insert the two wires into loosened terminals and tighten the screws. 3.3 INTERFACING TO ESA TRAINERS The interface can be connected to any of the ESA trainers through a 26 pin connector J1 on the interface. The procedure is as follows: 1. Switch off the power supply connected to the trainer.

5 5 2. Connect one end of 26 core ribbon cable to appropriate connector on the trainer as indicated by table Connect the other end of the cable to the 26 pin male connector J1 on the interface card. 4. Refer section 3.1 for power supply connections. 5. Switch on the power supply to the trainer and the interface and press RESET key on the trainer. Now the interface is ready for use. 4.0 DEMONSTRATION EXAMPLES The programming examples presented in this section demonstrate the use of relay output card with ESA trainers. Each demonstration program performs the following operations: i. Initializes the 8255 in mode 0 with port A, port B and port C as output ports. ii. Activates relays in sequence LSB to MSB of a particular port with a definite delay between successive relays and repeats this for all the three ports. During the execution of the program, the user can observe the response of the card by connecting LED indicators to relays connected to a port/ports. To do this, Connect each common terminal (C0,C1,C2,...etc) to +5V through 330 ohms resistors. Connect the anodes of LEDs to `normally open' contacts (B0,B1,B2,...etc) and the cathodes to ground. (Please refer section 3.2 for connection details) Please note that, The LED glows when the relay is activated. The LED does not glow when the relay is deactivated. During the execution of the program, the LEDs glow one at a time and shift from LSB to MSB of the particular port. 4.1 DEMONSTRATION PROGRAM FOR MPS 85-3 TRAINER ; Assume the interface is connected over J2 of the trainer. ; The trainer can be in KEYBOARD MODE or SERIAL MODE.

6 6 ADDRESS OPCODE LABLE MNEMONICS COMMENTS 8C00 3E,80 MVI A,80 ; Configure C02 D3,43 OUT CWR in mode 0 with port A, port B and port C as output ports. 8C04 AF LOOP: XRA A ; Deactivate relays 8C05 D3,41 OUT PORTB connected to 8C07 D3,42 OUT PORYC port B and port C 8C09 3C INR A ; Activate a relay 8C0A 06,08 MVI B,08H connected to 8C0C D3,40 LOOP1: OUT PORTA port A 8C0E F5 PUSH PSW 8C0F CD,45,8C CALL DELAY 8C12 F1 POP PSW 8C13 07 RLC ; Rotate bit pattern left by one bit 8C14 05 DCR B ; Check whether all 8C15 C2,0C,8C JNZ LOOP1 relays connected to port A are excited. If not jump to LOOP1 8C18 AF XRA A ; Deactivate relays 8C19 D3,40 OUT PORTA connected to 8C1B D3,42 OUT PORTC port A and port C 8C1D 3C INR A ; Activate a relay 8C1E 06,08 MVI B,08H connected to 8C20 D3,41 LOOP2: OUT PORTB port B 8C22 F5 PUSH PSW 8C23 CD,45,8C CALL DELAY 8C26 F1 POP PSW 8C27 07 RLC ; Rotate bit pattern 8C28 05 DCR B left by one bit 8C29 C2,20,8C JNZ LOOP2 ; Check whether all relays connected to port B are excited. If not jump to LOOP2 8C2C AF XRA A ; Deactivate relays 8C2D D3,40 OUT PORTA connected to 8C2F D3,41 OUT PORTB port A and port B 8C31 3C INR A ; Activate a relay 8C32 06,08 MVI B,08H 8C34 D3,42 LOOP3: OUT PORTC ; Connected to port C

7 7 8C36 F5 PUSH PSW 8C37 CD,45,8C CALL DELAY 8C3A F1 POP PSW 8C3B 07 RLC ; Rotate bit pattern 8C3C 05 DCR B left by one bit 8C3D C2,34,8C JNZ LOOP3 ; Check whether all 8C40 C3,04,8C JMP LOOP relays connected to port C are excited. If not jump to LOOP3 ORG 8C45H 8C45 21,FF,FF DELAY: LXI H FFFF ; To provide delay 8C48 2B LOOP4: DCX H between each relay 8C49 7D MOV A,L excitation. 8C4A B4 ORA H 8C4B C2,48,8C JNZ LOOP4 8C4E C9 RET 4.2 DEMONSTRATION PROGRAM FOR ESA 85-2 TRAINER ; Assume the interface is connected over J2 of the trainer. ; The trainer can be in KEYBOARD MODE or SERIAL MODE. ADDRESS OPCODE LABLE MNEMONICS COMMENTS 8C00 3E,80 MVI A,80 ; Configure C02 D3,43 OUT CWR in mode 0 with port A, port B and port C as output ports. 8C04 AF LOOP: XRA A ; Deactivate relays 8C05 D3,41 OUT PORTB connected to 8C07 D3,42 OUT PORYC port B and port C 8C09 3C INR A ; Activate a relay 8C0A 06,08 MVI B,08H connected to 8C0C D3,40 LOOP1: OUT PORTA port A 8C0E F5 PUSH PSW 8C0F CD,45,8C CALL DELAY 8C12 F1 POP PSW 8C13 07 RLC ; Rotate bit pattern left by one bit 8C14 05 DCR B ; Check whether all 8C15 C2,0C,8C JNZ LOOP1 relays connected to port A are excited. If not

8 8 jump to LOOP1 8C18 AF XRA A ; Deactivate relays 8C19 D3,40 OUT PORTA connected to 8C1B D3,42 OUT PORTC port A and port C 8C1D 3C INR A ; Activate a relay 8C1E 06,08 MVI B,08H connected to 8C20 D3,41 LOOP2: OUT PORTB port B 8C22 F5 PUSH PSW 8C23 CD,45,8C CALL DELAY 8C26 F1 POP PSW 8C27 07 RLC ; Rotate bit pattern 8C28 05 DCR B left by one bit 8C29 C2,20,8C JNZ LOOP2 ; Check whether all relays connected to port B are excited. If not jump to LOOP2 8C2C AF XRA A ; Deactivate relays 8C2D D3,40 OUT PORTA connected to 8C2F D3,41 OUT PORTB port A and port B 8C31 3C INR A ; Activate a relay 8C32 06,08 MVI B,08H 8C34 D3,42 LOOP3: OUT PORTC ; Connected to port C 8C36 F5 PUSH PSW 8C37 CD,45,8C CALL DELAY 8C3A F1 POP PSW 8C3B 07 RLC ; Rotate bit pattern 8C3C 05 DCR B left by one bit 8C3D C2,34,8C JNZ LOOP3 ; Check whether all 8C40 C3,04,8C JMP LOOP relays connected to port C are excited. If not jump to LOOP3 ORG 8C45H 8C45 21,FF,FF DELAY: LXI H FFFF ; To provide delay 8C48 2B LOOP4: DCX H between each relay 8C49 7D MOV A,L excitation. 8C4A B4 ORA H 8C4B C2,48,8C JNZ LOOP4 8C4E C9 RET 4.3 DEMONSTRATION PROGRAM FOR ESA 80 TRAINER ; Assume the interface is connected over J3 of the trainer. ; The trainer can be in KEYBOARD MODE or SERIAL MODE.

9 9 ADDRESS OPCODE LABLE MNEMONICS COMMENTS E,80 LD A,80 ; Configure D3,43 OUT (43H),A in mode 0 with port A, port B and port C as output ports E,00 LD A,00H ; Deactivate relays 8006 D3,41 OUT (41H),A connected to 8008 D3,42 OUT (42H),A port B and port C 800A 3C INC A ; Activate a relay 800B 06,08 LD B,08H connected to 800D D3,40 LOOP1: OUT (40H),A port A 800F F5 PUSH AF 8010 CD,41,80 CALL DELAY 8013 F1 POP AF RLCA ; Rotate bit pattern left by one bit DEC B ; Check whether all ,F5 JR NZ,LOOP1 relays connected to port A are excited. If not jump to LOOP E,00 LD A,00H ; Deactivate relays 801A D3,40 OUT (41H),A connected to 801C D3,42 OUT (42H),A port A and port C 801E 3C INC A ; Activate a relay 801F 06,08 LD B,08H connected to 8021 D3,41 LOOP2: OUT (41H),A port B 8023 F5 PUSH AF 8024 CD,41,80 CALL DELAY 8027 F1 POP AF RLCA ; Rotate bit pattern DEC B left by one bit 802A 20,F5 JR NZ,LOOP2; Check whether all relays connected to port B are excited. If not jump to LOOP2 802C 3E,00 LD A,00H ; Deactivate relays 802E D3,40 OUT (40H),A connected to 8030 D3,41 OUT (41H),A port A and port B C INC A ; Activate a relay ,08 LD B,08H 8035 D3,42 LOOP3: OUT (42H),A P ;Connected to port C 8037 F5 PUSH AF

10 CD,41,80 CALL DELAY 803B F1 POP AF 803C 07 RLCA ; Rotate bit pattern 803D 05 DEC B left by one bit 803E 20,F5 JR NZ,LOOP3; Check whether all HALT relays connected to port C are excited. If not jump to LOOP ,FF,FF DELAY: LD HL FFFFH ;To provide delay B BACK1: DEC HL between each relay C LD A,H excitation D DEC A ,FB JR NZ,BACK C9 RET 4.4 DEMONSTRATION PROGRAM FOR ESA 31 TRAINER ; Assume the interface is connected over J2 of the trainer. ; The trainer can be in KEYBOARD MODE or SERIAL MODE. ADDRESS OPCODE LABLE MNEMONICS COMMENTS A0 E8 START: MOV P2,#0E8H ;Configure 8255 in MOV R0,#03H ;mode 0, all ports MOV A,#80H ;as O/P ports F MOV DPTR,#00H 800B E4 LOOP : CLR A 800C MOV R0,#00H 800E F2 800F MOV R0,#01H 8011 F2 ;Deactivate all MOV R0,#02H ;the relays 8014 F MOV R1,#08H A 01 MOV R2,#01H 8019 EA LOOP1: MOV A,R2 ;Activate a relay 801A A8 82 MOV R0,DPTR ;of port(dptr) 801C F2 801D LCALL DELAY RL A ;Rotate bit pattern 8021 FA MOV R2,A ;left by one bit DEC R1 ;check whether all 8023 E9 MOV A,R1 ;relays connected to

11 F3 JNZ LOOP1 ;port(dptr)are ;excited. If not ;jump back 8026 A3 INC DPTR ;Get the next port 8027 E5 82 4E MOV A,DPTR 8029 B4 03 DF CJNE A,#03,LOOP ;Check all the ports ;are excited 802C C2 D5 CLR F0 ;To select MSG from ;PM 802E E MOV DPTR,#STR ;Load the MSG ;address to DPTR B LCALL 164BH ;Call the display ;routine LJMP 0000H ;Jump to the booting ;address 8037 C0 83 DELAY: PUSH DPH ;To provide delay 8039 C0 82 PUSH DPL ;between each relay 803B C0 E0 PUSH A ;excitation 803D MOV DPTR,#00H 8040 A3 DELAY1: INC DPTR 8041 E5 83 MOV A,DPH ORL A,DPL F9 JNZ DELAY D0 E0 POP A 8049 D0 82 POP DPL 804B D0 83 POP DPH 804D 22 RET 804E 0A 0A C STR: DB 0AH,0AH, 'RELAY INTERFACE TESTING E IS COMPLETED', AH,0AH,0AH,00H 805D E C 4F 4D 4C A 0A 0A DEMONSTRATION PROGRAM FOR ESA-68K TRAINER ; Assume the interface is connected over P3 of the trainer. PORTA EQU $80300 PORTB EQU $80302 PORTC EQU $80304

12 12 CNTPRT EQU $80306 ADDRESS OPCODE LABLE MNEMONIC COMMENTS FC 00 MOVE.B #$80,CNTPRT ;Configure ;8255 in ;mode 0 ;All ports ;as O/P FC 00 MOVE.B #$00,PORTC ;Deactivate ;relays to ;port B and FC 00 MOVE.B #$00,PORTB ;port C C 00 MOVE.B #$01,D0 ;Activate a 01 ;relay 04061C 13 C0 00 LOOP1: MOVE.B D0,PORTA ;connected to ;port A BSR $DELAY ;Call Delay 4C E3 18 ROL.B #$01,D0 ;Rotate bit ;pattern left ;by one bit F2 BCC.S $LOOP1 ;Check whether ;all relays ;connected to ;port A are ;excited. If ;not jump to ;LOOP A 13 FC 00 MOVE.B #$00,PORT A ;Deactivate ;relays FC 00 MOVE.B #$00,PORT C ;connected to ;port A & C A 10 3C 00 MOVE.B #$01,D0 ;Activate a 01 ;relay 04063E 13 C0 00 LOOP2: MOVE.B D0,PORTB ;connected to ;port B BSR DELAY 2A E3 18 ROL.B #$01,D0 ;Rotate bit ;pattern left ;by one bit.

13 A 64 F2 BCC.S LOOP2 ;Check whether ;all relays ;connected to ;port B are ;excited. If ;not jump to ;LOOP C 13 FC 00 MOVE.B #$00,PORTA ;Deactivate ;relays ;connected to FC 00 MOVE.B #$00,PORTB ;port A and B C 10 3C 00 MOVE.B #$01,D0 ;Activate a 01 ;relay C0 00 LOOP3: MOVE.B D0,PORTC BSR DELAY A E3 18 ROL.B #$01,D0 ;Rotate bit ;pattern left ;by one bit C 64 F2 BCC.S LOOP3 ;Check whether 04066E 4A FC DC.W $4AFC ;all relays ;connected to ;port C are ;excited. If ;not jump to ;LOOP C 00 DELAY: MOVE.B #03,D2 ;To provide 03 ;delay between C FF DEL: MOVE.W #$FFFF,D1 ;each relay FF ;excitation BACK: SUB.W #$01,D A 0C CMPI.W #$00,D E 66 F8 BNE.S BACK SUB.B #01,D C CMPI.B #00,D EC BNE.S DEL E 75 RTS 4.6 DEMONSTRATION PROGRAM FOR ESA 86/88-2 TRAINER

14 14 ; Assume the interface is connected over J4 of the trainer. ; The trainer can be in KEYBOARD MODE or SERIAL MODE. CS = 0. ADDRESS OPCODE LABLE MNEMONIC COMMENTS C C8 MOVW AX,CS E D8 MOVW DS,AX E D0 MOVW SS,AX 2006 B0 80 MOVB AL,#80 ;Configure BA E6 FF MOVW DX,#0FFE6 ;8255 mode 0 200B EE OUTB DX ;All ports as O/P 200C B MOVW AX,#0000 ;Deactivate relays 200F BA E2 FF MOVW DX,#0FFE2 ;connected to port B 2012 EE OUTB DX ;and port C 2013 BA E4 FF MOVW DX,#0FFE EE OUTB DX 2017 FE C0 INCB AL ;Activate a relay 2019 B3 08 MOVB BL,#08 ;connected to 201B BA E0 FF LOOP1: MOVW DX,#0FFE0 ;port A. 201E EE OUTB DX 201F 50 PUSH AX 2020 E8 6C 00 CALL 208F POP AX 2024 B1 01 MOVB CL,# C0 ROLB AL,CL 2028 FE CB DECB BL ;Rotate bit ;pattern left ;by one bit. 202A 75 EF JNE 201B ;Check whether all ;relays connected to ;port A are excited. ;If not jump to ;LOOP1. 202C B MOVW AX,#0000 ;Deactivate relays 202F BA E0 FF MOVW DX,#0FFE0 ;connected to port A 2032 EE OUTB DX ;and port C 2033 BA E4 FF MOVW DX,#0FFE EE OUTB DX 2037 FE C0 INCB AL ;Activate a relay 2039 B3 08 MOVB BL,#08 ;connected to port B 203B BA E2 FF LOOP2: MOVW DX,#0FFE2 203E EE OUTB DX 203F 50 PUSH AX 2040 E8 4C 00 CALL 208F

15 POP AX 2044 B1 01 MOVB CL,# D2 C0 ROLB AL,CL ;Rotate bit 2048 FE CB DECB BL ;pattern left ;by one bit. 204A 75 EF JNE 203B ;Check whether all ;relays connected to ;port B are excited. ;If not jump to ;LOOP2. 204C B MOVW AX,#0000 ;Deactivate a relay 204F BA E0 FF MOVW DX,#0FFE0 ;connected to port A 2052 EE OUTB DX ;and port B 2053 BA E2 FF MOVW DX,#0FFE EE OUTB DX 2057 FE C0 INCB AL ;Activate a relay 2059 B3 08 MOVB BL,#08 ;connected to port C 205B B4 E4 FF LOOP3: MOVW DX,#0FFE4 205E EE OUTB DX 205F 50 PUSH AX 2060 E8 2C 00 CALL 20BF POP AX 2064 B1 01 MOVB CL,# D2 C0 ROLB AL,CL ;Rotate bit 2068 FE CB DECB BL ;pattern left ;by one bit. 206A 75 EF JNE 205B ;Check whether all ;relays connected to ;port C are excited. ;If not jump to ;LOOP3. 206C 9A 5B 1B 00 FE CALLS 1B5B,0FE A 5B 1B 00 FE CALLS 1B5B,0FE C C8 MOVW AX,CS E C0 MOVW ES,AX 207A B8 A0 20 MOVW AX,#20A0 207D 9A 55 1B 00 FE CALLS 1B5B,0FE A 5B 1B 00 FE CALLS 1B5B,0FE A 5B 1B 00 FE CALLS 1B5B,0FE00 208C 90 NOP 208D 90 NOP 208E CC INT 3 208F E DELAY: MOVW CX,# DLY5: PUSH CX 2093 B9 FF 03 MOVW CX,#3FF

16 2096 90 DLY10: NOP 2097 E2 FD LOOP DLY10 2099 C3 RET 20A0 52 45 4C 41 59 DB 'RELAY INTERFACE TESTING 20A5 20 4F 55 54 50 IS COMPLETED',00H 20AA 55 54 20 49 4E 20AF 54 45 52 46 41 20B4 43 45 20 54

16 DLY10: NOP 2097 E2 FD LOOP DLY C3 RET 20A C DB 'RELAY INTERFACE TESTING 20A5 20 4F IS COMPLETED',00H 20AA E 20AF B B E 47 20BE C3 4F 4D 50 4C 45 20C APPLICATION NOTES There are many applications where the RELAY OUTPUT CARD is used. A few are given in this section to enable the user to become familiar with the interface. 5.1 POWER SUPPLY MONITOR The power supplied to an electric lamp or a fractional horse power motor or any other electric load can be controlled by a digital system (eg : a microprocessor based system) through the relay output card. A typical block diagram is shown in figure 5.1. When the input from the digital system at DA0 is a logic 0, the relay is deactivated. The relay contacts are in `normally closed' position (contact between A0 and C0) and no power is applied to the lamp or motor or any other electric load connected to B0. When the input from the digital system is a logic 1, the relay gets activated. The relay contacts change over from `normally closed' position to `normally open' position (contact between B0 and C0). The power supply connected to the common terminal C0 is supplied to the lamp or motor or any other electric load connected to B0.

17 5.2 TIMED BELL CIRCUIT In this application, a calling bell is rung for a particular duration after definite intervals of time. The block diagram is shown in figure 5.2. The input to the relay card is from a microprocessor based system.

17 TIMED BELL CIRCUIT In this application, a calling bell is rung for a particular duration after definite intervals of time. The block diagram is shown in figure 5.2. The input to the relay card is from a microprocessor based system. Suitable power required to operate the bell is connected to the common terminal C0. The coil of the bell is connected to contact B0. When the signal on DA0 is at logic 1, the relay gets activated and the bell rings. When the signal on DA0 is at logic 0, the relay gets deactivated and the bell does not ring. The microprocessor is programmed such that it applies logic 0's and logic 1's after predetermined delays. 5.3 ABSOLUTE ZERO LEVEL IN TTL LOGIC In TTL logic, logic 1 state corresponds to the voltage across the collector and emitter (grounded) of the output transistor when it is in OFF state (approximately 5V). The `logic 0' state corresponds to that, when it is in ON state. Hence the logic 0 state corresponds to saturation voltage `Vcesat' of the output transistor which is approximately 0.2V. In some applications, it may become necessary to get exactly zero volts for logic 0 state. This can be achieved by using the relay output card. The block diagram is shown in fig 5.3. The normally closed contact A0 is connected to ground and normally open contact B0 is connected to +5V. The output is taken across C0 and A0. (i.e, C0 and GND). When the input signal (at DA0) is a logic 1, the relay gets activated and the normally open contact (between C0 and B0) provides an output of +5V. When the input signal (at DA0) is a logic 0, the relay gets deactivated and the normally closed contact (between C0 and A0) provides an output of exactly 0V.

18 18

19 19 APPENDIX C : CONNECTOR DETAILS CONNECTOR J1 (26 PIN MALE CONNECTOR) PIN NO SIGNAL PIN NO SIGNAL 1 DC4 2 DC5 3 DC2 4 DC3 5 DC0 6 DC1 7 DB6 8 DB7 9 DB4 10 DB5 11 DB2 12 DB3 13 DB0 14 DB1 15 DA6 16 DA7 17 DA4 18 DA5 19 DA2 20 DA3 21 DA0 22 DA1 23 DC6 24 DC V 26 GND NOTE : DAO-DA7, DB0-DB7 AND DC0-DC7 are data input lines.

CONTENTS. 1.0 Introduction Description of the Circuit Installation Demonstration Examples 3

CONTENTS. 1.0 Introduction Description of the Circuit Installation Demonstration Examples 3 1 CONTENTS PAGE NO 1.0 Introduction 2 2.0 Description of the Circuit 2 3.0 Installation 2 4.0 Demonstration Examples 3 4.1 Demonstration Program for MPS 85-3 Trainer 4 4.2 Demonstration Program for ESA