Allen-Bradley 1756-DNB DeviceNet Communication Module

The Allen-Bradley 1756-DNB DeviceNet Bridge/Scanner module for ControlLogix is a dedicated DeviceNet master that bridges a DeviceNet network to the ControlLogix backplane. It provides one DeviceNet port via an open-style 5- or 10-pin plug for connecting the DeviceNet trunk. The module supports DeviceNet data rates of 125 Kbps, 250 Kbps, and 500 Kbps, with maximum segment lengths of 500 m, 250 m, and 100 m respectively, and it supports up to 64 nodes on the network. In a ControlLogix chassis, the 1756-DNB occupies a single slot and can be placed in any slot position. Power is drawn from the chassis with backplane current up to 850 mA at 5.1 V, plus DeviceNet supply current around 60 mA at 24 V DC; typical total power dissipation is about 3.5 W. The DeviceNet network and the backplane are connected with basic insulation, and the DeviceNet port is designed for continuous operation within standard DeviceNet electrical conditions. Firmware for the 1756-DNB includes revisions in the 12.x range, such as 12.006 on certain builds. Typical applications include reading inputs and writing outputs to DeviceNet devices (sensors, actuators, and I/O blocks) and configuring DeviceNet devices from the ControlLogix controller to support integrated automation tasks.