Consilium ST450EC - Page 12

12
ST450EC
v1.11
WIRING DIAGRAMS ST450EC:
ST450EC used as 4-20mA transmitter (2 wires):
GAS
DETECTOR
CON 1
0-25mA
1
1
Signal
PSU /
analog input
CONTROL
UNIT
Vin
2
2
+24 Vdc
GND
3
3
0 Vdc
B-
4
4
Rx (-)
Modbus RTU
RS485
Half Duplex
A+
5
5
Tx (+)
Do NOT connect GND (terminal 3) of the gas detector to 0 Vdc of the control
unit (or PSU) when the gas detector is used only with an analog output 4-20mA.
ST450EC used as MODBUS slave device:
GAS
DETECTOR
CON 1
0-25mA
1
1
Signal
PSU /
analog input
CONTROL
UNIT
Vin
2
2
+24 Vdc
GND
3
3
0 Vdc
B-
4
4
Rx (-)
Modbus RTU
RS485
Half Duplex
A+
5
5
Tx (+)
ST450EC used as MODBUS slave device and 2 wire 4-20 mA transmitter:
GAS
DETECTOR
CON 1
0-25mA
1
1
Signal
PSU /
analog input
CONTROL
UNIT
Vin
2
2
+24 Vdc
GND
3
3
0 Vdc
B-
4
4
Rx (-)
Modbus RTU
RS485
Half Duplex
A+
5
5
Tx (+)