When Standard Outputs Can’t Keep Pace
High-speed packaging, converting, and rotary knife lines live or die by output timing. A few microseconds of jitter can scrap product or stall a cycle. The Allen-Bradley 1756-OB16IEFS from Rockwell Automation solves that problem. It is a ControlLogix scheduled fast isolated DC output module built for position-based output control using the Motion Axis Output Cam (MAOC) instruction.
This is the only module that can run the MAOC instruction in a remote chassis while receiving output data. That single capability changes how machine builders architect high-speed motion systems.
What Makes the 1756-OB16IEFS Different
The module delivers 16 scheduled, high-speed, individually isolated, electronically fused outputs. Each point switches within a nominal 14 microseconds, with a maximum of 23 microseconds, off-to-on and on-to-off. It operates across a 10-30 V DC range with a 12/24 V DC sink/source voltage category.
Because it is a CIP Sync slave-only device, the module uses CIP Sync for scheduling and timestamps. It enables time-scheduled output control for outputs 0 through 15 at a minimum 5-microsecond interval. For engineers chasing repeatable cam profiles, that precision is the whole point.
Key Specifications
| Parameter | Value |
|---|---|
| Series | ControlLogix |
| Module Type | DC Output Module |
| Outputs | 16 scheduled, isolated, e-fused |
| Operating Voltage | 10-30 V DC |
| Max Current per Point | 2 A at 30 °C, 1 A at 60 °C |
| Max Current per Module | 8 A at 30 °C, 4 A at 60 °C |
| Backplane Current | 350 mA at 5 V, 3 mA at 24 V |
| Isolation Voltage | 50 V continuous |
| Power Dissipation | 3.6 W at 60 °C |
| Terminal Block | 1756-TBCH or 1756-TBS6H |
Solving Real Engineering Pain Points
Pain Point: Output Timing Drift
On flying-shear and registration applications, standard outputs introduce timing uncertainty. The 1756-OB16IEFS schedules outputs directly against CIP Sync time, so cam events fire at defined positions rather than estimated delays. PWM cycle time ranges from 1 ms minimum to 1 hour maximum, with on-time accuracy of ±20 µs.
Pain Point: Fault Behavior Chaos
When a controller faults, uncontrolled outputs damage product. This module lets you configure fault mode states (Hold Last State, On, or Off), fault mode duration (1, 2, 5, 10 s, or Forever), final state after fault duration, and program mode states. Every option defaults to Off except fault duration, which defaults to Forever.
Pain Point: Point-Level Protection
An external fuse failure takes down a whole bank. Here, each point carries electronic fusing and individual isolation. Maximum off-state leakage stays below 0.1 mA per point, and on-state voltage drop reaches only 0.4 V DC at 2 A.
Integration and Selection Notes
Install the module in a chassis fitted with a removable terminal block housing. Only the 1756-TBCH and 1756-TBS6H terminal blocks apply. Because the module communicates over CIP Sync, wiring into your network may require an external gateway or connection module. Confirm cables and gateways with your supplier before commissioning.
Before ordering, verify your chassis supports the required RTB, confirm your application needs scheduled output control, and check that your controller firmware handles the MAOC instruction. Oil AutoTech offers hands-on technical selection help for exactly these questions. Please verify current lifecycle status and availability with Oil AutoTech before ordering.
For oil, gas, and industrial automation teams that cannot wait on lead times, Oil AutoTech keeps fast-dispatch spares ready. Contact Oil AutoTech today for pricing and availability.
