1791D-0B16P

The 1791D-OB16P is an Allen-Bradley manufactured CompactBlock I/O module for Devicenet. This module features a compact assembly, with embedded output channels and communication interface supporting DeviceNet protocol. This module is ideally used for implementing Distributed I/O architecture.

The 1791D-OB16P is compatible for use with PLC2, PLC3 and PLC5 product family, SLC500 controllers and SoftLogix programmable Logic Controllers with DeviceNet scanner capability.This module supports communication rate such as 125Kbps @ 500m (1600ft); 250Kbps @ 200m (600ft); 500Kbps @ 100m (330ft) for Thick cable and 125Kbps @ 420m (1230ft); 250Kbps @ 200m (490ft); 500Kbps @ 75m (245ft) for flat media. The 1791D-OB16P has Sixteen (16) sourcing output channels, in Two (2) groups of Eight (8) channels each. This CompactBlock I/O module has configurable data exchange cycles such as Polled, Cyclic and Change-of-state (COS). When using the cyclic mode, the module exchanges data with the processor in a continuous pattern, in regular intervals according to the configured cycle time. In Polled mode, data exchange is initiated by the master device sending the polled message to the CompactBlock module. In Change-of-state mode, data exchange mode, is executed depending on the state of a certain trigger.

The module is built with status indicator that aids in monitoring and troubleshooting. This LED indicators provide status feedback regarding Mod/Net status via bi-color LED lights of red/green; Logic status via green LED and I/O status via a yellow indicator light.

When wiring signals to the module, recommended wire size is 14 gauge (2 sq.mm ) stranded wire with 3/64 inch maximum insulation.

The I/O data exchange happens through cyclic, polled, or change-of-state connection. The selection of connection mode is done via the module’s DeviceNet scanner configuration. When a cyclic operation is used, the master sends and receives data from the CompactBlock module at preconfigured intervals. As a polled device, the master sends polled messages to the module, initiating the communication. In its change-of-state mode, the master sends output data only when the period set for communication has expired or when the user control program wants an update from the module. In this type of connection, the slave automatically sends data changes to the master as it occurs. The 1791D-0B16P organizes the sourcing outputs in two groups of eight. For monitoring, the module has status indicators such as red or green for Mod/Net status, green for logic status, and yellow for I/O status. It has an on-state voltage range between 10- 30 VDC, an on-state voltage drop of 0.5 Volts DC at the rated maximum on-state current of 0.5 A, and a maximum off-state leakage of 1.0 mA. All outputs have a maximum module current of 4.0A with a maximum surge current of 1.0A for 10 milliseconds, repeatable every 2 seconds. Base module dimensions are 150 X 48 X 38 millimeters (or 5.91 X 1.9 X 1.5 inches).