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Availability: Obsolete
OBSOLETE** 16-channel Digital Optomux Brain Board for Serial Networks (See below for replacement)

Production Specification

*** End of Life *** - No stock on hand.

Please note: Because we can no longer obtain essential parts, we cannot continue to manufacture the B1.

Drop-in replacement: The E1 brain board is a drop-in replacement for the B1 and adds Ethernet capability as well as support for multiple protocols, including Optomux, Modbus/TCP, and OptoMMP. For more information on migration, see form 1567, the E1 and E2 Architecture and Migration Overview.

The B1 brain board is an intelligent processor that operates as a slave device to a host computer, via an RS-422/485 serial link, to control digital I/O modules. The B1 mounts on Opto 22 I/O racks with header connectors; racks are available that accept Standard (G1), G4, Quad Pak, or SNAP I/O modules. The B1 uses the Optomux protocol.

Use this software developer toolkit with the B1 brain: Optomux Protocol drivers and utilities.

Compatible I/O and mounting racks: Set or read your B2 or E2 jumpers quickly using these configurators:


B1 and B2

B1 Power Requirements

5 .0 - 5.2 VDC @ 0.5 amps
(includes digital module requirements)

B2 Power Requirements

5 .0 - 5.2 VDC @ 0.5 amps
(excludes analog module requirements*)

Operating Temperature

0 °C to 70 °C
95% humidity, non-condensing


RS-422/485 communications
50-pin female header connector to I/O mounting rack

Data Rates

300, 600, 1200, 2400, 4800, 9600, 19200, and
38400 baud


  Repeat Mode


Up to 5,000 feet total length with up to
32 Optomux stations maximum. **
Up to 5,000 feet between stations with up to 256
Optomux stations maximum.


Full duplex, two twisted pairs, a signal common
wire, and a shield


Power, receive, and transmit



Address (0 to 255)
Baud rate
Multidrop or repeat mode
2- or 4-pass protocol

** ±15 VDC ± 0.25 V required for the analog modules. Current depends on the
number and type of modules installed. A 24 VDC power supply is required for
analog modules that need a current loop source.
* Extend line length and/or number of OPTOMUX stations with the AC30A/B
network adapter.


E1 and E2 Architecture and Migration Overview

The E1 and E2 brain boards are Ethernet-ready I/O and communication processors for digital and analog I/O systems. Designed as drop-in replacements for Opto 22's serial-based B1 and B2 brain boards, the E1 and E2 support both serial and Ethernet networking and multiple simultaneous protocols, including Optomux, OptoMMP, and Modbus/TCP.

This overview describes the system capabilities of the E1 and E2 and illustrates methods for migrating existing Optomux systems to use Ethernet networking, while preserving existing I/O racks, modules, and field wiring.

Optomux 16-Channel Digital and Analog Brain Boards Data Sheet

The B1 digital and B2 analog Optomux brain boards are intelligent digital processors that operate as slave devices to a host computer. Each brain board contains a microprocessor that provides the necessary intelligence to communicate with a host computer and also perform control functions at each channel of I/O.

B1 and B2 User's Guide

Digital B1 and analog B2 brain boards use the Optomux protocol. For new installations, E1 and E2 brain boards are preferred. This guide includes B1- and B2-specific information that used to be in form #203, which is now obsolete. For Optomux information, see form #1572, the Optomux Protocol Guide.

Optomux Protocol Guide

The Optomux Protocol Guide provides complete command documentation and examples for programmers using either the Opto 22 Optomux Protocol Driver or the Optomux protocol itself. This guide replaces the previous forms #203 (Optomux Protocol User's Guide) and #92 (Optoware User's Guide).

B1 and B2 Jumpers in-the-box

This one-page document shows you quickly how to set jumpers on Opto 22 B1 and B2 brain boards.

CE Declaration: Low Voltage

This document is the Manufacturer's Declaration for the listed products as mentioned in the attachment - to which this confirmation refers - that they are in accordance with the mentioned European, international and/or national standards and regulations.

AutoCAD Drawings

This file contains AutoCAD drawings of Opto 22 products dating from 1988 to 2003. These are the same drawings that have been available on our BBS. Included is an Excel file describing the file names and relevant Opto 22 part numbers.

CAD Drawing: B1 Digital Brain Board

This CAD file is a drawing of the digital Optomux B1 brain board, a legacy product.

Optomux Protocol drivers and utilities

This file installs drivers for E1, E2, B1, B2, and serial B3000 and B3000-B brains. It is based on the "iolib_optomux.dll" library. This toolkit is recommended for all new Optomux-based applications because it supports Optomux communications over both Ethernet and serial networks.

The toolkit can emulate the interface that the earlier library "OptoMWD.dll" provided; however, using this interface is not required. This legacy interface capability is included to help an existing OptoMWD.dll user make a smoother migration to this newer toolkit. The legacy utilities OptoScan and OmuxUser are also included.

This toolkit is compatible with Windows XP and Windows 2000 operating systems. It is not compatible with .NET programming languages.

E1/B1 Brain Jumper Configurator

Easily configure your E1 brain jumper settings for protocols, brain's address, baud rate, and communication mode, using this interactive demo.

E2/B2 Brain Jumper Configurator

Easily configure your E2 brain jumper settings for protocols, brain's address, baud rate, and communication mode, using this interactive demo.

Read E1/B1 Jumper Settings

Use this interactive demo to read the current configuration of your E1 (or B1) using its jumper settings.

Read E2/B2 Jumper Settings

Use this interactive demo to read the current configuration of your E2 (or B2) using its jumper settings.