17
INM 7700 Rev 12
APPENDIX A: TYPICAL WIRING CONNECTIONS
FOR SPECIFIC APPLICATIONS .
Hazardous
Area
Hazardous
Area
Figure A1: 2-
wire transmitters
Hazardous
Area
Figure A5:
2-channel switch inputs
Hazardous
Area
Figure A6:
Low-level analogue inputs (RTD’s)
Figure A2: 2-
wire transmitters with 250Ω conditioning
Hazardous
Area
Figure A3:
Thermocouple/mV input
Hazardous
Area
Figure A7:
2-channel switch/proximity input
Hazardous
Area
Figure A8:
Single channel switch/proximity input
Hazardous
Area
Figure A4:
2-wire transmitter/switch input
Safe
Area
3
4
1
2
7
8
5
6
Power +26.6V
Power +26.6V
Logic signal
Logic signal
Power Bus
Safe
Area
3
4
1
2
MTL7756ac
Receiver
7
5
3
4
1
2
MTL7755ac
Receiver
Safe
Area
3
4
1
2
MTL7743
MTL7744
7
8
5
6
Safe
Area
3
4
1
2
MTL7742
5
6
Safe
Area
3
4
1
2
M
250
Ω
1-5V
Power +26V
Power Bus
Safe
Area
Safe
Area
3
4
1
2
M
Power +26.6V
Signal
Power Bus
Safe
Area
3
4
1
2
250
4 -20mA
Power +26V
Signal
Power Bus
1-5V
