Allen-Bradley 1771-SDN DeviceNet Scanner Module

Allen-Bradley 1771-SDN DeviceNet Scanner Module is a 1-slot, two-channel DeviceNet scanner designed for PLC‑5 backplanes, enabling a single processor to poll two DeviceNet networks or device groups. It communicates with the PLC‑5 processor via block‑transfer I/O for efficient data exchange and supports two DeviceNet scan counters. Each channel draws 50 mA from a 24 VDC supply, while the backplane provides 5 VDC at up to 0.8 A, and the module occupies a single slot in the I/O chassis. The unit is typically installed in 1771-A1B through -A4B (or later) backplanes and uses a Node Address up to 63. The 1771-SDN/C variant is the DeviceNet Scanner Module designation, and it is documented as scanning I/O and process messages on the DeviceNet network with block‑transfer communication to the PLC‑5 processor. A DeviceNet wiring arm (1771‑WN) is used for field connections, completing the network interface. This module is referenced in official and distributor listings and is listed in ODVA materials as part of the 1771‑SDN family for PLC‑5 deployments.