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$230.00 (USA and Canada only)

Availability: In stock
RS-232 to RS-422/485 Converter 220 VAC

Production Specification

RS-232 to RS-422/485 Converter 220 VAC

AC7A and AC7B

Power Requirements

115 VAC ± 10 VAC @ 50-60 Hz
220 VAC ± 20 VAC @ 50-60 Hz

Power Consumption

0.1 amps @ 115 VAC
5 watts (dissipation)

Temperature Range

0 °C to 70 °C
0 to 95% Humidity (non-condensing)

Optical Isolation

4,000 V between RS-232 and RS-422/485

RS-232 Interface

25-pin, DB-25 female connector

RS-422/485 Interface

Screw terminals or 9-pin, DB-9 female connector

Baud Rate

Up to 38,400 baud; 115.2KBd in Rev. L (AC7A)
and later and in Rev. C (AC7B) and later.

RS-232 Distance

Up to 50 feet

RS-422/485 Distance

Up to 5,000 feet at 38,400 baud (3,000 feet at 115,200 baud)


RS-422/485 full duplex over two twisted pairs and a ground.
Additional twisted pairs for RTS and CTS.
Also supports RS-485 2-wire mode. This requires user to
build a custom RS-232 cable.


Transmit, receive, RTS, CTS, and power


PC-Based I/O Overview

This document shows examples of system architecture for PC-based I/O control systems and lists Opto 22 products that work together for PC-based control. System examples include:

  • Ethernet systems using SoftPAC, a software-based programmable automation controller programmed with PAC Control
  • Ethernet systems using the OptoMMP protocol
  • Direct control of I/O using no I/O processor (no brain)
  • Serial control using a brain and the mistic or Optomux protocol
  • High-speed control using the Pamux protocol
NOTE: Before choosing to use a PC for control, consider groov EPIC.  A groov EPIC processor offers many features similar to a PC, such as a Linux OS with optional secure shell access; cybersecurity features; Ethernet, USB, and HDMI ports; and the ability to run the control program and HMI on the same hardware. In addition, a groov EPIC system offers real-time control using traditional programming languages; guaranteed-for-life I/O on the same chassis; industrial toughness for hazardous locations; and easier integration with company computer networks, manufacturing, business, and facility systems, and cloud-based services & software.

AC7A/B Adapter Card Data Sheet

The AC7A/B is a stand-alone adapter card that converts RS-232 serial communication to RS-422/485 serial communication, which is directly compatible with the Optomux family of intelligent brain boards.

AC7A - AC7B Users Guide

This document gives instructions for installing the AC7A/B adapter card in an Optomux network in 4-wire RS-422/485 mode with a PC and how to communicate with equipment other Optomux.

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