Satec System 295 Installation And Operation Manual page 165

RS-485 Multidrop Cable Connections
1. Install the 120 ohm 1/4 watt terminating resistors externally at the end
points of the cable, on the last instrument in the chain and on the master
computer.
2. The shield of each segment of the cable must be connected to the
ground at one end only.
3. Avoid star or stub connected topologies.
Powermeters
9-pin DB9 male connectors
#1
TxD
RxD
TxD-
RxD-
#2
TxD
RxD
TxD-
RxD-
#32
TxD
RxD
TxD-
RxD-
Technical Specifications Appendix D Cable Drawings - Computer Connection
25-pin Computer Connector
Shield
6
7
8
9
Shield
6
7
8
9
Shield
6
7
Ω
120
8
9
IBM PC/compatible
A 25-pin DB25 female connector
RxD
3
TxD
2
RxD-
Ω
120 15
TxD-
14
RTS
4
CTS
5
RTS-
16
CTS-
17
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