Product Overview
The Allen-Bradley 1756-OB16IEF is a ControlLogix fast isolated output module built for applications where timing and fault tolerance matter. It provides 16 individually isolated 24V DC digital outputs with a 10-30V DC operating range, electronic fusing, and per-point protection. This is not a general-purpose output card. It is a peer-to-peer fast output module with Pulse Width Modulation (PWM) capability, designed for demanding control tasks where response speed and isolation are critical.
Key Specifications That Matter
Fast Response and PWM Control
The 1756-OB16IEF responds to system transition commands in less than 25 microseconds. Its PWM cycle time ranges from 1 ms minimum to 1 hour maximum, with on-time accuracy of +/-20 microseconds. These specs suit precision tasks like proportional valve control or fast actuation sequences.
Per-Point Isolation and Electronic Fusing
Each of the 16 outputs is individually isolated, with 50V continuous isolation voltage. Electronic fusing protects each point, and the module supports configurable fault-mode states: Hold, Last State, On, or Off. Fault-mode durations include 1, 2, 5, 10 seconds, and Forever.
Current Ratings
Maximum output current per point is 2 A at 30 degrees Celsius and 1 A at 60 degrees Celsius. Per module, the maximum is 8 A at 30 degrees Celsius and 4 A at 60 degrees Celsius. Minimum load current is 1 mA per point. Surge current reaches 4 A for 10 ms per point, repeatable every 2 seconds.
Where This Module Fits
The 1756-OB16IEF suits oil and gas, water treatment, and industrial automation systems that require fast, isolated digital outputs. Typical uses include driving solenoid valves, pilot relays, and indicator circuits where fault tolerance and quick response are priorities. The PWM function supports applications needing duty-cycle control, such as heater modulation or proportional actuation.
Compatibility and Integration
This module is a CIP Sync slave-only device. It uses CIP Sync for timestamps and scheduling, so another module must act as the master clock on the network. A removable terminal block (RTB) is required for installation. The only compatible RTBs are the 1756-TBCH and 1756-TBS6H. The module has no enclosure and mounts directly in a ControlLogix chassis.
Selection Checklist
Before ordering, confirm your application needs 16 isolated outputs at 10-30V DC, verify your system supports CIP Sync with an external master clock, and ensure you have a compatible RTB. The 1756-OB16IEF delivers fast, reliable output control for critical processes. Contact Oil AutoTech today for pricing and availability.
