Applications - Facility Explorer - Part No. 24-10143-918 - Field Device

RS-485 Option Module Installation Instructions

Document type
Installation Guide
Document number
Part No. 24-10143-918
Document revision
Revision date

This document describes how to mount and wire an RS-485 option module for an FX80 controller.

The RS-485 option module is a dual port, optically isolated RS-485 adapter, with two 3-position, removable screw-terminal connector plugs. Each port has an RS-485 bias switch to set or remove biasing. LEDs verify power from the controller and indicate RS-485 trunk message traffic.

The FX80 controller has two onboard RS-485 ports, which always operate as COM1 and COM2. Installed serial option modules continue COM port numbering based on proximity to the controller (where the option module closest to the controller base operates as the next available serial COM ports). For example, if the RS-485 is attached directly to the controller, the option module operates as COM3 (upper port) and COM4 (lower port).

Figure 1. Dual RS-485 option module

Table 1. Dual RS-485 option module




RS-485 A port COMn (next available). For example, COM3.


RS-485 B port COMn + 1. For example, COM4.