Table of Contents
Advertisement
Communication Ports
4.1.2 RS485/422 Data Ports
and RS422 can accommodate multi-drop networks, for master-slave serial network
communications. For both RS485/RS422 connections, the following general
guidelines should be followed:
•
•
•
•
•
•
Note
Transient protection is provided on all RUGGEDCOM RP110 terminals. Lightning
strikes and ground surge currents can cause large momentary voltage differences
between ends of communication links. To ensure maximum reliability of the entire
link, all equipment should have similar transient protection installed.
The following shows the recommended RS485 wiring.
2
1
1
2
3
4
5
18
To minimize the effects of ambient electrical noise, use shielded cabling.
The correct polarity must be observed throughout a single sequence or ring.
The number of devices wired should not exceed 32, and total distance should be
less than 1219 m (4000 ft) at 100 kbps.
The Common terminals should be connected to the common wire inside the
shield.
The shield should be connected to earth ground at a single point to avoid loop
currents.
The twisted pair should be terminated at each end of the chain (typically with a
120 Ohm resistor and a 10nF capacitor in series across the twisted pair).
3
4
RUGGEDCOM RP110 Device
Common (Isolated Ground)
Negative
Positive
Shield to Earth (Connected At a Single Point)
5
5
120Ω 10nF
120Ω 10nF
6
RUGGEDCOM RP110
Installation Manual, 01/2021, C79000-G8976-1012-04
Advertisement
Table of Contents
