Allen-Bradley 1756-OB32

Technical specifications

Manufacturer

Allen-Bradley

Manufacturer part no.

1756-OB32

Type

Digital output module

Application

I/O module

Used with

ControlLogix 1756 chassis

Outputs

32 (16 points/group)

Voltage category

12/24V DC source

Operating voltage range

10…31.2V DC

Output delay time

60 µs nom/1 ms max 200 µs nom/1 ms max

Current draw @ 5.1V

300 mA

Current draw @ 24V

2 mA

Total backplane power

1.58 W

Power dissipation, max

4.8 W @ 60 °C (140 °F)

Thermal dissipation

16.37 BTU/hr

Off-state leakage current per point, max

0.5 mA per point

On-state voltage drop, max

200 mV DC @ 0.5 A

Current per point, max

0.5 A @ 50 °C (122 °F) linear derating 0.35 A @ 60 °C (140 °F)

Current per module, max

16 A @ 50 °C (122 °F) linear derating 10 A @ 60 °C (140 °F)

Surge current per point, max

1 A for 10 ms per point, repeatable every 2 s @ 60 °C (140 °F)

Load current, min

3 mA per point

Scheduled outputs

Synchronization within 16.7 s max, reference to the Coordinated System Time

States in Fault mode per point

Hold last state, On or Off (Off is default)

Isolation voltage

250V (continuous), basic insulation type, outputs to backplane. 125V (continuous), basic insulation type, outputs group to group., No isolation between individual outputs.

Module keying

Electronic, software configurable

Fusing

Not protected. A fused IFM can be used to help protect outputs. See publication 1492-TD008. However, the ControlLogix system has been agency certified using only the ControlLogix RTBs, that is, 1756-TBCH, 1756-TBNH, 1756-TBSH, and 1756- TBS6H. Any application that requires agency certification of the ControlLogix system that uses other wiring termination methods can require application-specific approval by the certifying agency.

RTB keying

User-defined mechanical

Slot width

1

Terminal block torque specs

1756-TBCH, 1756-TBCHXT 0.5 Nm (4.4 lbin)

Enclosure type

None (open-style)

Temperature code

T4

Technical documents (1)

• Rockwell Automation technical data 1756-TD002

Key features

• 32 outputs with 16 points per group
• Fault mode holds last state, on or off, per point
• Electronic keying set through software
• Conformal coated, rated for 0 to 60 °C operation
• Scheduled outputs referenced to Coordinated System Time

About the Allen-Bradley 1756-OB32

The 1756-OB32 is a ControlLogix 32 point 12/24V DC output module (10-31 VDC Output 32 Pts, 36 pin). Its 32 source outputs sit at 16 points per group, with an operating range of 10 to 31.2V DC. Current is 0.5 A per point at 50 °C, derating linearly to 0.35 A at 60 °C, and 16 A per module at 50 °C, derating to 10 A at 60 °C. It is 1 slot wide and works from 0 to 60 °C.

What is the 1756-OB32 used for?

It switches 12/24V DC loads from a ControlLogix controller on 32 source outputs, a dense choice where slots are short. In fault mode each point can hold its last state, turn On or turn Off, with Off as the default. Scheduled outputs are synchronised within 16.7 s maximum, referenced to the Coordinated System Time.

Lifecycle and successor

Active (Rockwell Automation lifecycle status, checked 24 October 2026).

Before you order

What to photograph or confirm so the right unit is quoted.

Read the catalog number 1756-OB32, the series letter and the firmware revision from the label. Send us a photo of the label and we confirm the match before we quote.