User's Manual

19
Introducing 5000/5100:
Features
1.3.12 RS-485
A standard RS-485 port is also available on the JP3 to constitute multi-station
systems. Though it is simple and low cost, care must be taken to ensure proper
operations.
z
The data rate is 125 kbps.
z
Compatible to CipherLAB 510, 520 and so on.
z
Maximum network run length is 1000 meters
z
No fork, nor star connections. As depicted below, connections b, d & f are
acceptable but not others.
Figure 10: RS-485 topology
z
Use AWG 22, shielded twist cables or Cat 5 UPT cables.
z
Terminators help to absorb reflections and should be placed at both “physical”
ends. A slide switch turns on/off an on-board termination circuitry.
z
For the RS-485 network to work properly, a unique station ID has to be assigned
to each terminal first.