RS-485 wiring - Facility Explorer - Part No. 24-10143-861 - Supervisory Device - FX Supervisory Controller

FX80 Supervisory Controller Installation Instructions

Facility Explorer
Product name
FX Supervisory Controller
Document type
Installation Guide
Document number
Part No. 24-10143-861
Document revision
Revision date

On the controller's top side, two RS-485 ports operate as COM1 and COM2. Each port is capable of up to 115,200 baud, and uses a 3-position, screw terminal connector.

Use shielded, twisted-pair, 18-22 AWG cabling to wire in a continuous daisy chain fashion to other RS-485 devices: minus-to-minus, plus-to-plus, and shield-to-shield. Connect the shield wire to earth ground at one end only.

For more information about wiring guidelines, refer to FX-PC Series Controllers MS/TP Communications Bus Technical Bulletin (LIT-12011670).

Figure 1. RS-485 wiring example

Table 1. RS485 wiring example




RS-485 port A (COM1) is often used to support a trunk of LP-FXRIO16-0 modules. Do not mix LP-FXRIO16-0 modules with other types of RS-485 devices on the same RS-485 trunk.


RS-485 port B (COM2) supporting a network of other field devices using RS-485 field communication.


RS-485 devices on the same network should use the same protocol and baud rate. Up to 32 or more devices may be supported depending on device specifications.