Allen-Bradley 1756-OB16D

Technical specifications

Manufacturer

Allen-Bradley

Manufacturer part no.

1756-OB16D

Type

Digital output module

Application

I/O module

Used with

ControlLogix 1756 chassis

Short trip

8 A for 180 ms, min 10 A for 120 ms, min

No load

Off-state detection only

Output verification

On-state detection only

Pulse test

Configurable maximum pulse width

Time stamp of diagnostics

±1 ms

Outputs

16 diagnostic (8 points/group)

Pilot duty (DC-13SQ)

2 A @ 30 °C (86 °F) 1 A @ 60 °C (140 °F)

Voltage category

24V DC source

Operating voltage range

19.2…30V DC

Output delay time

60 µs nom/1 ms max 630 µs nom/5 ms max

Current draw @ 5.1V

250 mA

Current draw @ 24V

140 mA

Total backplane power

4.64 W

Power dissipation, max

3.3 W @ 60 °C (140 °F)

Thermal dissipation

11.25 BTU/hr

Off-state leakage current per point, max

1 mA per point

On-state voltage drop, max

1.2V DC @ 2 A

Current per point, max

2 A @ 30 °C (86 °F) linear derating 1 A @ 60 °C (140 °F) linear derating

Current per module, max

8 A @ 30 °C (86 °F) linear derating 4 A @ 60 °C (140 °F) linear derating

Surge current per point

4 A for 10 ms per point, repeatable every 1 s

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, and output group-to-group, No isolation between individual group outputs

Module keying

Electronic, software configurable

Technical documents (1)

• Rockwell Automation technical data 1756-TD002

Key features

• Diagnostic outputs arranged in groups of 8 points
• Electronically fused per point
• Pulse test with configurable maximum pulse width
• Diagnostic time stamp of ±1 ms
• Fault mode holds last state, On or Off

About the Allen-Bradley 1756-OB16D

The 1756-OB16D is a ControlLogix 19-30 VDC diagnostic output module with 16 points (36 pin). It works from 19.2…30V DC, with 16 diagnostic outputs in groups of 8 points. Current is 2 A per point and 8 A per module at 30 °C, derating linearly to 1 A per point and 4 A per module at 60 °C.

What is the 1756-OB16D used for?

It switches 24V DC source loads from a ControlLogix controller and reports their state, including off-state detection with no load and on-state output verification. In fault mode each point can hold its last state, go On or go Off, with Off as the default. Scheduled outputs synchronise 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-OB16D, 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.