$299.00 (USA and Canada only)

Availability: In stock
SNAP 32-channel Digital (Discrete) Output Module, 5-60 VDC Load Sinking

Please call (800) 321-6786 to order.


Production Specification

The SNAP-ODC-32-SNK digital output module (load sinking) provides 32 digital output channels in one compact SNAP module. This module is ideal for OEMs and others with applications with high point counts, or for those requiring a large number of digital output channels on one SNAP I/O rack. The high-density configuration reduces per-point costs of digital I/O systems by providing up to eight times as many I/O channels in the same space.

If you're unsure whether you need a sinking or sourcing module, see the sinking/sourcing demo or watch the brief Sinking vs. Sourcing video.

Part of the SNAP PAC System, the module mounts on a SNAP PAC rack with a SNAP PAC brain or rack-mounted controller. Analog, digital, and serial I/O modules can all be on the same rack. Such an I/O unit is also well suited for PC-based control or for use as intelligent remote I/O for an Allen-Bradley Logix PLC system, such as ControlLogix, MicroLogix, or CompactLogix.

For easy field wiring, use the SNAP-ODC-HDB or compact SNAP-UDC-HDB breakout rack and the SNAP-HD-BF6 header cable. A wiring harness with flying leads (SNAP-HD-CBF6) is also available.

NOTE: If you need a Factory Mutual-approved version, see the SNAP-ODC-32-SNK-FM.

For switching signals with higher current, see the SNAP-UDC-HDB-G4 breakout board, which mounts G4 input modules that handle up to 3 amps per point (G4 modules are sold separately).

Reference Charts: Build your system in the SNAP I/O Configurator.




Switching Voltage

5–60 VDC

5–60 VDC

Nominal Switching Voltage

12–24 VDC

12–24 VDC

Logic Voltage and Current

5 VDC ± 0.1 @ 150 mA

5 VDC ± 0.1 @ 150 mA

Maximum Off State Voltage

60 VDC

60 VDC

Output Leakage, Typical

<10 microamps per channel (60 V, 70 °C)

<10 microamps per channel (60 V, 70 °C)

Maximum Load per Point

0.25 A

0.25 A

Voltage Drop

0.15 VDC @ 0.25 A

0.15 VDC @ 0.25 A

Surge (1 sec.)

1 A

1 A

Output Arrangement

32 output channels; 4 groups of 8 outputs each. Points in each group share a common positive connection.

32 output channels; 4 groups of 8 outputs each. Points in each group share a common negative connection.

Maximum Operating
Common Mode Voltage

250 V

250 V

Isolation: Field to Logic

1500 V

1500 V

Output Turn-On/Off Time

100 microseconds

100 microseconds

Polling time from I/O proces­sor to module1

2–30 ms typical2

2–30 ms typical2


None; use optional OptoTerminal-G20 diag­nostic display or breakout rack.

None; use optional OptoTerminal-G20 diagnostic display or breakout rack.

Maximum Number of HDD Modules on One Mounting Rack



Torque, hold-down screws

4 in-lb (0.45 N-m)

4 in-lb (0.45 N-m)

Torque, connector screws

5.26 in-lb (0.6 N-m)

5.26 in-lb (0.6 N-m)

Operating Temperature

-20 to 70 °C

-20 to 70 °C

Storage Temperature

-40 to 85 °C

-40 to 85 °C

Agency Approvals








1 Affects turn-on and turn-off determination
2 Time varies based on the SNAP PAC I/O processor (brain or on-the-rack controller), processor configuration, and Ethernet host communication activity.

Modules, Cables, and Breakout Boards Compatibility Charts

This document shows which SNAP I/O modules, breakout boards, and cables can be used together.

Comparison Chart: SNAP 4-Channel and High-Density Digital Modules

This document compares 4-channel and high-density SNAP digital I/O modules.

SNAP PAC System Product Guide

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

SNAP High-Density Digital Modules Data Sheet

SNAP I/O high-density digital modules from Opto 22 provide 16 or 32 digital input or output points in one compact SNAP module. These modules are ideal for OEMs and others who have high point-count applications, or for anyone requiring more than 64 digital points on a single SNAP PAC rack. The high-density configuration reduces per-point costs of digital I/O systems by providing up to eight times as many I/O points in the same space.

SNAP high-density digital modules are part of the SNAP PAC System. They can also be used as part of intelligent remote I/O with an Allen-Bradley Logix PLC system.

HDD modules require a SNAP PAC R-series controller or a SNAP PAC brain for I/O processing. These modules work with standard wired controllers and brains and with Wired+Wireless models.

SNAP High-Density Digital Module User's Guide

This guide covers how to install and test SNAP 16-channel and 32-channel digital modules. These modules provide 16 or 32 points of digital input or digital output in the same space as a 4-channel digital module. They are ideal for OEMs and for anyone who needs up to 512 digital points on a single mounting rack.

Case Study: AAQUA NV

In 2005, AAQUA NV was looking for a way to cut costs while still providing robust automated systems.

They learned about Opto 22 products and did some research. They liked what they saw.

Thirteen years and approximately 70 installations later, AAQUA NV is still exploring the possibilities of Opto 22 products and adding new features to their system.

Declaration of Conformity (EMC, LVD, RoHS)

This document is the Manufacturer's Declaration of Conformity for the products listed herein, in accordance with European, international, and/or national standards and regulations.

Sinking or Sourcing Technical Note

Are you confused about sinking and sourcing when wiring DC circuits? This technical note explains what sinking and sourcing mean, explores where you would use one wiring method rather than the other, and shows how to use a digital output module with your DC circuit.

New I/O Breakout Boards Increase Current Switching Up to 12x, Simplify Wiring, and Save Panel Space

Press release for SNAP-UDC-HDB-G4 and SNAP-UDC-HDB breakout racks for SNAP 32-point SNAP digital I/O modules

SNAP PAC System Migration Technical Note

This document describes migration options for customers integrating the SNAP PAC System with older Opto 22 systems. It explains the SNAP PAC System's similarities and differences with earlier systems, defines legacy products, and shows how to mix old and new hardware.

Customers moving to the SNAP PAC System may also want to consult form #1693, Legacy and Current Product Comparison and Compatibility Charts.

Opto 22 RoHS 2 Statement of Compliance - Restriction of Hazardous Substances

This document is a statement of compliance with the EU Directive 2011/65/EU, Restriction of Hazardous Substances (RoHS 2). This document lists Opto 22 products that comply with the substance restrictions of the RoHS2 directive.

Using ioDisplay 6.0 with SNAP High-Density Digital Modules Technical Note

This technical note is for customers using SNAP high-density digital modules with ioControl 6.1 and ioDisplay 6.0.

UL Approval Document

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

CE Declaration: EMC

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.

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.

CAD 3D Drawing: SNAP-ODC-32-SRC Digital Output Module

This CAD file contains a 3-dimensional drawing of the SNAP-ODC-32 32-channel digital input and output modules. The drawing applies to the following modules:

CAD Drawing: SNAP-ODC-HDB Breakout Rack

This is a CAD drawing of the SNAP-ODC-HDB breakout rack, which is used with two SNAP high-density digital output modules: SNAP-ODC-32-SNK and SNAP-ODC-32-SRC.

Optomation Systems ioControl Functions

A piecewise linear interpolator function PLI under ioControl 5.1. The ioScript version can be easily copied to your program. It can be used for any of the following applications:

  • Calculating volume from tank level measurement (PV=Level Q=Volume)
  • Setpoint Generator (PV=Elapsed Time Q=Required Setpoint, eg Temp or Flow)
  • Flow rate profiling (PV=Dif Pressure Q=Flow Rate)
  • Split Range Control (PV=Common Output Q=Valve1 profile)
  • Adaptive Gain (PV=Secondary Variable Q=PID Gain Value)

PPP sample code and configuration for ioControl

The zip file contains sample ioControl code for the SNAP Ultimate I/O and SNAP-LCE. The code demonstrates how these controllers can exchange information via PPP and modems. A document is included to explain the samples.

This file contains sample code.

Note: Before you download, read the Legal Agreement.

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: Securing SNAP Module

A quick overview on securing a SNAP Module to a SNAP rack.

Video: Removing a SNAP Module

A quick overview on removing a SNAP module.

Demo: Accuracy vs Resolution

What's the difference between accuracy and resolution in analog I/O specifications? Try your own specs in the calculator.

Demo: Sinking vs Sourcing

Switching a DC circuit? Learn about sinking and sourcing, and the digital output modules to use with each.