Allen-Bradley 1756-OB16IS ControlLogix Digital Output Module

Configured for high-speed digital actuation in ControlLogix platforms, the Allen-Bradley 1756-OB16IS (1756-OB16IS Digital Output Module) provides direct physical/electrical execution of isolated DC output switching within CIPSync synchronized networks.

Hardware Specifications

I/O Density Scaling and Deterministic Networks

The 1756-OB16IS module manages I/O density scaling by offering 16 individually isolated output channels, suitable for high-density control requirements in automated drive assemblies. The module is engineered for integration within CIPSync architectures, ensuring sub-millisecond deterministic timing across the backplane bus. Firmware flash compatibility is supported via the ControlLogix studio environment, allowing for precise module configuration and real-time state monitoring. The isolated circuit design minimizes cross-channel interference, providing robust electrical separation during simultaneous switching operations. Proper module function is contingent upon backplane communication velocity settings that align with the master controller's scan cycle.

Frequently Asked Questions

Q: Is the 1756-OB16IS module compatible with non-isolated ControlLogix bases?

A: The module is designed for the ControlLogix chassis environment. While it occupies a standard slot, the isolated wiring requirements must be met at the 36-pin terminal interface to maintain channel-to-channel isolation.

Q: What is the requirement for CIPSync architecture?

A: The module utilizes CIPSync to provide time-stamped data and deterministic coordination. The host controller and network must be configured to support time-synchronization protocols to enable the full feature set of this module.

Field Installation Guidelines

• Terminal Connector: Ensure the 36-pin connector is fully seated and the housing is locked into the module. Utilize proper wire ferrules to prevent fraying at the connection points.
• Grounding: Terminate the signal return paths according to the isolation specifications. Avoid common-mode ground loops by ensuring the DC supply ground is referenced appropriately to the isolation boundaries.
• Module Seating: Align the module with the chassis guide rails. Push evenly until the top and bottom latches click, ensuring the backplane pins are fully engaged.
• Field Power: Apply 10-30 VDC field power to the module only after confirming the wiring polarity. Reversed polarity on the isolated DC inputs can trigger fault states.
• Heat Dissipation: Maintain a minimum clearance of 5 cm above and below the chassis in the control cabinet to allow for natural convective cooling of the module's electronic components.