Siemens Argus 7SR21 Technical Manual page 494

7SR21 & 7SR22 - Installation Guide
Figure 4.3-5 Standard Comms + Additional Ethernet Ports (RJ45 shown, Duplex LC Fibre Optic similar)
Notes
1) Recommended terminations are pre-insulated & must be crimped using approved tooling.
2) RS485 (block "B" terminals 14, 16, 18, 20 and optional COMMS MODULE) connections are by screened,
twisted pair cable.
Ensure that these terminals are not obscured by other wiring runs.
Cable should be RS485 compliant.
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