Allen-Bradley 1756-OF8

Technical specifications

Manufacturer

Allen-Bradley

Manufacturer part no.

1756-OF8

Type

Analog output module

Application

I/O module

Used with

ControlLogix 1756 chassis

Outputs

Eight voltages or current

Output range

± 10V 0…20 mA

Resolution

Voltage: 15 bits across 10.5V - 320 µV/bit, Current: 16 bits across 21 mA - 325 nA/bit

Current draw @ 5.1V

200 mA

Current draw @ 24V

300 mA

Total backplane power

8.22 W

Voltage and current ratings

Backplane: 5.1V DC, 200 mA max; 24V DC, 300 mA max, Output Voltage: -10…+10V, Output Current: 0…20mA

Power dissipation

8.22...2 W; 0...750 ohm loads

Thermal dissipation

28.03 BTU/hr

Open circuit detection

Current output only (Output must be set to >0.1 mA)

Overvoltage protection

± 24V DC

Short circuit protection

Electronically current limited to 21 mA or less

Settling time

< 2 ms to 95% of final value with resistive loads

Calibrated accuracy @ 25 °C (77 °F)

Better than 0.05% of range from 0…21 mA, -10.4…10.4V

Offset drift

20 µV/ °C 80 nA/°C

Module error

Voltage: 0.1% of range, Current: 0.2% of range

Module scan time, min

12 ms floating point 8 ms integer

Data format

Integer mode (left justified, 2 s complement) IEEE 32-bit floating point

Module conversion method

R-Ladder DAC, monotonicity with no missing codes

Isolation voltage

250V (continuous), Basic insulation type, Output Channels to Backplane, No isolation between individual output channels

Module keying

Electronic, software configurable

RTB keying

User-defined mechanical

Slot width

1

Wiring category

1 - on signal ports

Enclosure type

None (open-style)

Technical documents (1)

• Rockwell Automation technical data 1756-TD002

Key features

• Eight outputs for voltage or current signals
• Integer or IEEE 32-bit floating point data format
• Output channels isolated from backplane at 250V continuous
• Open circuit detection on current outputs
• Conformal coated, operating up to 60 °C on Series C chassis

About the Allen-Bradley 1756-OF8

The 1756-OF8 is a ControlLogix 8 point analog output module for current or voltage (20 pin). Output range is ±10V or 0…20 mA, with voltage resolution of 15 bits across 10.5V and current resolution of 16 bits across 21 mA. Settling time is under 2 ms to 95% of final value with resistive loads, and total backplane power is 8.22 W.

What is the 1756-OF8 used for?

It sends eight analog signals, each voltage or current, from a ControlLogix controller to valves, drives and other field devices. Data is handled in integer mode or IEEE 32-bit floating point, with a minimum module scan time of 12 ms for floating point and 8 ms for integer. Current outputs are electronically limited to 21 mA or less for short circuit protection.

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-OF8, 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.