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Availability: Obsolete
OBSOLETE Wired+Wireless SNAP PAC Ethernet Brain, analog/digital/serial, with high-speed digital functions

Production Specification

*** NOTE: This part is obsolete and no longer available. ***


The SNAP-PAC-EB1-W brain provides the same features as the SNAP-PAC-EB1 and adds a wireless LAN interface as well.

An I/O and communications processor for your control system, the SNAP-PAC-EB1-W is designed primarily to work in distributed systems controlled by a SNAP PAC S-series or R-series controller. This brain can also be used in remote I/O with Allen-Bradley industrial PLC systems such as MicroLogix, or other A-B PLCs using explicit messaging.

The SNAP-PAC-EB1-W provides local intelligence that frees the controller (PAC or PLC) for supervisory tasks. As an I/O processor, the SNAP PAC brain independently handles functions such as latching, counting, thermocouple linearization, watchdog timers, and PID loop control. These functions continue to work on the brain even if communication with the controller is lost.

The SNAP-PAC-EB1-W brain includes a wireless LAN interface that supports 802.11a, b, and g network standards. The brain can be used in infrastructure or ad-hoc mode. For security, 802.11i standards are supported, including WPA2-AES as well as WPA and WEP for backwards compatibility.

In addition, the brain communicates over a standard 10/100 Mbps Ethernet network using two switched Ethernet network interfaces. Because these interfaces share a single IP address and act just like an Ethernet switch, SNAP PAC brains can be installed in a multi-drop (daisy-chain) configuration, extending the control network without the added expense of additional Ethernet network hardware. (Note that the wireless LAN interface does not provide access to other brains in a daisy-chain configuration, as this interface is independent.) SNAP PAC brains can also be installed in a star configuration using standard, off-the-shelf Ethernet network components.

The SNAP-PAC-EB1-W brain can run on a wireless LAN, on a wired network, or on both at once.

I/O Modules
The SNAP-PAC-EB1-W brain supports all the SNAP I/O analog, digital, and serial input and output modules available on the Opto 22 website. These modules can all be mixed on the same mounting rack and placed in any position on the rack. The brain and modules mount on a SNAP PAC rack, which holds up to 4, 8, 12, or 16 modules.

NOTE: In order to use Opto 22 serial modules with an EB2 brain, the I/O should be controlled by a SNAP PAC controller running a PAC Control strategy.
Since the same rack and I/O are used regardless of network, you can switch from wired to wireless and back again without having to add parts, reconfigure I/O, or change field wiring.

The SNAP-PAC-EB1-W brain offers high-speed digital functions, including high-speed counting (up to 20 KHz, depending on the module), quadrature counting, pulse generation and measurement, and TPO (time-proportional output). Pulse generation and measurement require PAC Control and a SNAP PAC controller, or using the brain with Allen-Bradley PLC systems. For a complete list of features and specifications, see form #1689, the SNAP PAC Brains Data Sheet, under the Docs & Downloads tab.

The SNAP-PAC-EB1-W brain supports communication using multiple protocols running simultaneously over Ethernet. Most customers use the PAC Project software suite for control, monitoring, and data acquisition. At the same time, you can communicate using other methods, including EtherNet/IP, Modbus/TCP, SNMP, SMTP, FTP, and OptoMMP. Communication with OPC 2.0-compliant clients is available through OptoOPCServer.

If you don't need high-speed digital functions, choose the SNAP-PAC-EB2-W brain instead.

If you don't need wireless capability, see the SNAP-PAC-EB1.

For a complete list of features and specifications, see the SNAP PAC Brains Data Sheet.

Compare SNAP PAC controllers and brains.

If you are not using PAC Project software and a SNAP PAC controller with this brain and instead need to communicate directly with it, see the SNAP PAC .NET OptoMMP SDK.

Build your system in the SNAP I/O Configurator.

Ethernet and Serial Brains [Ethernet Brains are Obsolete 3/1/22]

Power Requirements

5.0–5.2 VDC at 750 mA maximum (does not include module power requirements)

-W Models: 5.0–5.2 VDC at 1.0 A maximum (not including module requirements)



Backup battery for real-time clock

Rechargeable (recharges whenever the brain has power). 5-year life when power is off. (replacement part number: SNAP-PAC-BATTERY-ML2430). (Models manufactured before August 2007 have a 3-volt CR2032 lithium battery, available in retail stores. See original user guide for replacement steps.)

Hold-down screw

Torque: 8 in-lb (0.9 N-m)

Operating Temperature

-20 to 60 °C

Storage Temperature

-40 to 85 °C


0–95% humidity, non-condensing

Agency certifications

-EB models (except -EB-W): UL, CE, RoHS, DFARS; UKCA
-EB-W models: CE, UL, DFARS, UKCA ; U.S., FCC Part 15 Subpart C; Canada, IC RSS-210
-SB models: CE, RoHS, DFARS; UKCA


30 months from date of manufacture

Ethernet Brains (EB) only

Wired Ethernet Network Interfaces

IEEE 802.3 network, 10Base-T and 100Base-TX. Supports Auto MDI-X (crossover cable not needed). Two switched interfaces, allowing multi-drop (daisy-chain) or standard star network configuration.

Maximum Ethernet Segment Length

100 meters with Category 5 or superior UTP
For 100 Mbps at this distance, use Category 5 or superior solid UTP.

Wireless LAN interface*

  Frequency 802.11a
  Frequency 802.11b/g
  Transmit Power
  Antenna Connector

Separate IP address
Infrastructure, Ad-Hoc
802.11i: AES - Compatible with WPA2 Personal, TKIP - Compatible with WPA Per­sonal, WEP. Note: TKIP/AES security is not supported in Ad-Hoc mode.
5.180–5.24 GHz, 5.745–5.825 GHz
2.412–2.472 GHz, 2.484GHz
15 dBm maximum
Reverse polarity SMA (RP-SMA or RSMA)
Supported within an SSID (Service Set Identifier) only

Serial Brains (SB) only

Network interfaces

RS-485, 2- or 4-wire, twisted pair(s), with shield

Serial data rates

300 baud to 230.4 Kbaud

Range: Serial multidrop

32 stations maximum on a segment (including PC, controller, repeaters, and I/O units); up to 3000 ft (914 m) on a segment

* Requires Wired+Wireless model (SNAP-PAC-EB1-W or SNAP-PAC-EB2-W)

Using Modbus Devices with Opto 22 Products Technical Note

This technical note introduces the Modbus protocol and gives you basic information for using it to communicate between Opto 22 products and other devices. Because Modbus/TCP and Modbus serial are handled differently by various manufacturers, the tech note describes specific areas that may be a concern and includes troubleshooting suggestions.

SNAP PAC System Specification Guide

This guide is a comprehensive introduction to the SNAP PAC System. The guide describes the system's components (software, controllers, I/O processors, and I/O); shows how to build a basic system and how to expand it; and includes installation instructions, wiring diagrams, dimensional drawings, and specifications for parts.

SNAP PAC Brains Data Sheet

NOTE: Due to the unavailability of essential parts, SNAP PAC brains are obsolete and no longer available. Instead of Ethernet-based brains, use a SNAP-PAC-R1 controller/brain; it has all the same features plus additional power (and programmability, if you need it). For serial brain options, contact Opto 22 Product Support. 

SNAP PAC brains are powerful and versatile I/O and network communications processors. Designed primarily to work in distributed systems controlled by a SNAP PAC controller, SNAP PAC Ethernet brains can also be used as intelligent remote I/O for groov EPIC systems and Allen-Bradley Logix-based PLC systems.

SNAP PAC brains provide local intelligence for functions such as latching, counting, thermocouple linearization, watchdog timers, and PID loop control.

This document covers the following SNAP PAC brains:

SNAP PAC Controller and Brain Comparison Chart

This document compares features of SNAP PAC hardware controllers (SNAP PAC S-series and R-series) and SNAP PAC brains, all part of the SNAP PAC System.

NOTE: Due to the unavailability of essential parts, all SNAP PAC brains are obsolete and no longer available. Use rack-mounted controllers instead of Ethernet-based brains. For serial brain options, contact Opto 22 Product Support.

SNAP PAC System Product Guide

This document lists and describes all current Opto 22 SNAP PAC System part numbers, including PAC Project software, SNAP PAC controllers, and SNAP I/O modules of all kinds. SNAP PAC mounting racks and SNAP power supplies are also listed.

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)
  • 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.

SNAP PAC Controllers and Brains Firmware README

This README file lists revision changes made to the firmware used in SNAP PAC S-series, R-series, and SoftPAC controllers; SNAP PAC EB-series and SB-series brains; and G4EB2 and G4D32EB2 brains.

SNAP PAC I/O Coprocessor Firmware README

This README file lists changes to the I/O coprocessor firmware available in rack-mounted Opto 22 controllers and brains manufactured starting in 2016.

I/O coprocessors can be present in the SNAP PAC R-series controllers, and in SNAP PAC EB-series and SB-series brains. Instructions to find out if your device has an I/O coprocessor are included in this README and in the PAC Manager User's Guide.

NOTE: The following products manufactured with I/O coprocessors have firmware R3.0a; you do not need to update the firmware in these products at this time:


IO4AB User's Guide

This guide provides instructions on how to set up EtherNet/IP messaging between an Allen-Bradley® Logix™ controller and Opto 22’s SNAP PAC I/O using Opto 22’s EtherNet/IP Configurator as well as Allen-Bradley’s RSLogix™ 5000 software.

EtherNet/IP for SNAP PAC Protocol Guide

This guide provides detailed descriptions of the EtherNet/IP commands that can be accessed when using remote Opto 22 I/O with an Allen-Bradley controller.

Legacy Edition, PAC Manager User's Guide

This document is the Legacy Edition of the PAC Manager User's Guide. It includes information about both SNAP PAC hardware and older hardware.

Use this guide if you are using any legacy hardware (SNAP Ultimate, SNAP Ethernet, and SNAP Simple I/O, E1 and E2 brain boards) with PAC Manager (software part number PACMANAGER).

If you are using SNAP PAC controllers and SNAP PAC brains only, use Form 1704, PAC Manager User's Guide instead of this guide.

PAC Manager User's Guide

This guide shows you how to use PAC Manager to assign IP addresses, configure I/O, and inspect and maintain Opto 22 SNAP PAC hardware. PAC Manager is part of the PAC Project Software Suite and also available separately (part number PACMANAGER).

NOTE: If you are using older Opto 22 hardware in addition to SNAP PAC controllers and brains, use the Legacy Edition of this guide, form #1714.

SNAP PAC Brains User's Guide

NOTE: Due to the unavailability of essential parts, all SNAP PAC brains (EB-series) are obsolete and no longer
available. Instead of Ethernet-based brains, use a SNAP-PAC-R1 controller/brain; it has all the same features plus additional power (and programmability, if you need it). For serial brain options, contact Opto 22 Product Support.

SNAP PAC brains, one of the four components of the SNAP PAC System, provide I/O processing and network communications for your distributed SNAP PAC System. SNAP PAC Ethernet brains can also be used as intelligent remote I/O in a groov EPIC system or an Allen-Bradley Logix-based PLC system.

This guide shows you how to install and use all SNAP PAC brains:

OptoMMP Protocol Guide

This guide is for programmers who are writing custom applications to communicate with Opto 22 memory-mapped devices. These devices include groov EPIC processors; groov RIO modules; SNAP PAC controllers and SNAP PAC EB and SB brains; G4EB2 brains; SNAP Ultimate, SNAP Ethernet, and SNAP Simple I/O; E1 and E2 brain boards, and SNAP-LCE controllers.

The guide describes how to use the IEEE 1394-based OptoMMP memory-mapped protocol for programming. The guide also contains the complete memory map for all Opto 22 memory-mapped devices.

NOTE: This guide replaced previous individual programming guides for SNAP Ultimate I/O (form #1312) and SNAP Ethernet I/O (form #1227). This document was formerly called the "SNAP Ethernet-Based I/O Units Protocols and Programming Guide."

UKCA Declaration of Conformity (EMC, LVD, RoHS)

This document is the Manufacturer's Declaration of Conformity for the products listed herein, in accordance with the rules, regulations and standards of the United Kingdom. The models cited have been tested to the essential requirements listed in the Standards section, and fully comply with the legislation as listed in UK Legislation section.

White Paper: The Case for Intelligent Remote I/O

This white paper explores the use of intelligent remote I/O in industrial automation systems. Employing a distributed architecture, rather than centralized control, offers three advantages: minimizing single points of failure, spreading the load, and maximizing scalability.

The paper details applications that could be made more efficient by using built-in functions offered by intelligent remote I/O. It also gives a specific example of how distributed intelligence could be used in a PLC system.

CE Declaration: R&TTE

This declaration of conformity applies to the R&TTE Directive of the European Union (1999/5/EC).

Replacing the SNAP PAC Rechargeable Battery Technical Note

Several SNAP PAC controllers and brains contain a rechargeable backup battery. The battery recharges whenever the brain has power and retains data for an extended period of time with the power off.

You should never have to replace this battery, but if you do, this technical note shows you how.

Opto 22 Starts Corporate Blog

Opto 22 introduces corporate blog to keep customers and partners better Informed.

Quick Guide: Troubleshooting Info from SNAP PAC Systems

This technical note provides a quick guide about diagnostic files to collect and send in to Opto 22 Product Support for analysis when troubleshooting a SNAP PAC System.

Overcoming Concerns about Wireless PACs and I/O in Industrial Automation

This white paper discusses four concerns engineers may have when considering the use of wireless Ethernet for industrial automation: security, network performance and reliability, availability and cost of I/O components, and the necessity of choosing between wired and wireless solutions up front.

The paper considers steps automation manufacturers could take to address these concerns and looks at the wired/wireless offering from Opto 22.

Using Intelligent SNAP I/O with Allen-Bradley PLC Systems

This technical note introduces SNAP I/O (brain, mounting rack, and I/O modules) for Allen-Bradley industrial PLC systems that use EtherNet/IP, including ControlLogix, CompactLogix, and MicroLogix.

The technical note briefly presents communication concepts, such as implicit and explicit messaging, and describes how to use implicit messaging to communicate with an A-B RSLogix-based PLC system.

Updating the Loader on a SNAP Device

It is rarely necessary to update the loader in a SNAP PAC controller or brain, but if you need to, this document shows you how. If you have questions, contact Opto 22 Product Support.

UL Approval Document

This document lists all Opto 22 part numbers that have the Underwriters Laboratory (UL) approval.

Firmware for all SNAP PAC products

Firmware for all SNAP PAC products (single download)

See the README document for information on changes and fixes in the current version of this product's firmware.

NOTE: Opto 22 recommends that you always use the most recent release of PAC Manager. Depending on the shipment date or the version number of the firmware currently installed on your SNAP-PAC-R or SNAP-PAC-S controller, older versions of PAC Manager cannot install certain levels of firmware:
  • As of February 22, 2022, some SNAP-PAC-R and SNAP-PAC-S controllers ship with new Ethernet components, along with PAC Firmware R10.4d (or higher) and new bootloader firmware to support the new components. PAC Firmware R10.4d (or higher) will not permit installing firmware lower than R10.4d on these controllers. To update firmware on these controllers, you need PAC Manager R10.4c or higher.
  • Effective April 2, 2018, some SNAP PAC controllers and brains have new flash components. These units shipped with firmware R9.5g (or higher) and new bootloader firmware. PAC firmware versions R9.5f and lower are not compatible with the new component. If you inadvertently install firmware R9.5f or lower on one of these units, you can recover by using the Failsafe Bootloader Mode to install firmware R9.5g or higher.
    • For more information about the new flash component, see KB87213.
    • For details on Failsafe Bootloader Mode, see "Replacing Damaged Firmware" in the PAC Manager User's Guide (form 1704).
  • To install PAC firmware R9.2c or higher on the following controllers only, use PAC Manager R10.4b (or higher), installed by either PAC Project 10.4002 or build 7 of the PAC Manager R10.4b installer. Wireless versions are not affected by this issue:
    • SNAP-PAC-R1
    • SNAP-PAC-R1-B
    • SNAP-PAC-R2

SNAP-PAC-EB1-W Brain Firmware

This download contains current firmware for the SNAP-PAC-EB1-W brain.

Current firmware for all SNAP PAC brains and controllers is available in a single download here.

Video: SNAP PAC System Overview

This overview describes the four integrated components of the SNAP PAC system: software, controllers, brains and I/O. This hardware and software system is designed for industrial control, remote monitoring and data acquisition.

Video: Dual Ethernet Interfaces: Controllers vs. Brains

A quick overview of Dual Ethernet Interfaces: Controllers vs. Brains.

Video: Webinar: Controller Redundancy in PAC Control 9

Learn how to implement controller redundancy in SNAP PAC systems.

Playlist: Opto 22 I/O for Allen-Bradley

Learn about Opto 104AB using this playlist of videos.

PID: Reaction Curve Tuning for Interactive PID algorithms

Tune your real-world PID control loop with this graphical tuner. Plug in your data and get calculated P, I, and D values, plus scan rate.

SNAP PAC Networking

Learn the basics about dual ports, redundancy, segmenting, and daisy chaining of SNAP-PAC networking in this interactive demo.