TELEDYNE OLDHAM SIMTRONICS OLCT 80 d, User Manual

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OLCT 80
GAS TRANSMITTER
USER MANUAL
NPO80GB
Revision F.1
57
4.8.3 OLCT 80 in RS485 network topology (Modbus)
Figure 42: wiring in RS485 network topology (Modbus).
Item Description
A. 24 VDC power supply. RS485 line.
B. Auxiliary input #1, 4-20 mA, 24 VDC.
C. Auxiliary input #2, 4-20 mA, 24 VDC.
D. Fault relay output. Dry contact. Interrupting capacity: 30 VDC - 250 VAC – 2A.
E. Alarm #2 relay output. Dry contact. Interrupting capacity: 30 VDC - 250 VAC – 2A.
F. Alarm #1 relay output. Dry contact. Interrupting capacity: 30 VDC - 250 VAC – 2A.
G. 120 Ω end-of-line resistor. (To be connected if the sensor is the last in the line.)
H. RS485 line output to subsequent sensor. Parallel terminal on A2.
J. 24 VDC power output to the next sensor in series. Parallel terminal at A1.
Recommended cable type:
Shielded cable designed for RS485 communication, e.g., Belden 3841 cable.
4.8.4 Grounding the housing
Connect the housing's earth terminal to the ground in accordance with regulation. The
OLCT 80
has a dedicated terminal for grounding located on the outside of the housing (Figure 2, 3).
4.8.5 Closing the cover
The cover must be tightly closed before connecting the cable to the terminal of the central system.
Insert and tighten the locking screw (Figure 2, 4).