Mircom TX3 Series Installation Manual page 43

4.5 RS-485
An RS-485 terminal lets you easily connect multiple Telephone and Card Access
Controllers across a network. The RS-485 connection is situated at the bottom
middle of the main controller board and consists of two separate terminals, each
for an input and output.
Connect the RS-485 input terminal to the RS-485 output terminal of another
controller. See figures 19, 20, 21 and 22.
You can close JW5 on the first and last controllers instead of using end-of-line
120 Ω resistors.
If there are problems with RS-485 communication, close both JW7 and JW8 on
either the first or last controller connected by RS-485.
Note:
Recommended cables:
•
•
Maximum total length:
•
•
UL Listed TX3-CX Card Access System Installation Manual
Version 2
LT-6906 Copyright 2019
Use twisted shielded pair grounded at one end.
RS485 cables
• Belden 3109A RS-485, (4 pr) 22 AWG (7x30) or equivalent
• Belden 9842 RS-485, (2 pr) 24 AWG (7x32) or equivalent
• Belden 9841 RS-485, (1 pr) 24 AWG (7x32) or equivalent
CAT5 Cables
• Belden 72001E ETHERNET Cat 5e 2 Pair, 24 AWG or equivalent
• Belden 70006E Cat 5e, 100Mb/s, Quad, AWG 22 (1) or equivalent
4000 feet (1244 m) for 22 AWG
2500 feet (762.5 m) for 24 AWG
Setup of the Card Access Controller
43