ABB COMMANDER 100 Operating Manual page 5

...2.2 Two-wire and Four-wire Connection
C100/V100
Fig. 2.1a Two-wire Operation – Panel Mounted Instruments
Fig. 2.1b Two-wire Operation – Wall-/Pipe-Mounted Instruments
C150
20
21
Tx+/Rx+
22
Tx–/Rx–
23
GND
24
11 12 13
Tx+/Rx+
Tx–/Rx–
GND
2 ELECTRICAL INSTALLATION...
Host Computer
+5V
Tx+
Tx–
Rx+
Rx–
GND
0V
Host Computer
'B'
+5V
Tx+
1.8kΩ Pull-up
Tx–
Resistor
Rx+
'A
Rx–
'B
1.8kΩ Pull-down
Resistor
GND
0V
'B'
'A'
1.8kΩ Pull-up
Resistor
'A
'B
1.8kΩ Pull-down
Resistor
'A'
3