Product Overview
The Allen-Bradley 1771-SDN is a DeviceNet Scanner Module developed by Rockwell Automation to give PLC-5 processors a native bridge onto DeviceNet networks through the Bulletin 1771 I/O chassis platform. Occupying a single slot in any 1771-A1B through 1771-A4B chassis, the 1771-SDN operates as the master (scanner) on the DeviceNet segment, exchanging cyclic, polled, strobed, and change-of-state I/O data with slave devices such as drives, block I/O adapters, photoelectric sensors, valve manifolds, and operator interface terminals, while simultaneously passing that data to the host PLC-5 processor through standard block-transfer messaging over the 1771 backplane.
Distinguished by its two independent DeviceNet channels, each with its own status indicators and node addressing, the 1771-SDN effectively gives a PLC-5 system two separate DeviceNet segments from a single chassis slot, doubling network capacity and allowing engineers to segment devices by function, criticality, or baud-rate requirement. Communication speed is selectable up to 125 Kbps across each channel, and up to 63 nodes may be addressed per network using the front-panel node-address switches. Configuration is performed through RSNetWorx for DeviceNet software, where the scan list, device parameters, and fault actions are defined graphically before being downloaded to the scanner.
As the foundational DeviceNet interface for the classic PLC-5 platform, the Allen-Bradley 1771-SDN remains one of the most widely deployed scanner modules in mature industrial installations. Although the PLC-5 family is no longer in new-sales production, the 1771-SDN continues to serve as a critical maintenance and retrofit component across thousands of manufacturing plants, process facilities, and material-handling systems worldwide. For reliability teams, system integrators, and OEM service organizations supporting legacy PLC-5 assets, the 1771-SDN represents a proven, fully documented, and immediately deployable solution for restoring or extending DeviceNet capability on the 1771 platform.
Technical Specifications
| Parameter Name | Parameter Value |
|---|---|
| Product Model | 1771-SDN |
| Manufacturer | Rockwell Automation / Allen-Bradley |
| Product Type | DeviceNet Scanner Module for 1771 I/O Chassis |
| Network Protocol | DeviceNet (master/scanner and slave modes supported) |
| DeviceNet Channels | 2 independent channels (Port 1 and Port 2) |
| Communication Rate | 125 Kbps maximum |
| Node Address Range | 0 to 63 (default 63), set via front-panel switches |
| Slave Device Capacity | Up to 63 devices per network |
| Backplane Current Draw | 0.8 A @ 5 V DC |
| DeviceNet Power Consumption | 24 V DC, 50 mA per channel (Class 2) |
| Isolation | Optical isolation between backplane and DeviceNet channel, tested at 500 V AC for 60 s |
| Chassis Compatibility | 1771-A1B through 1771-A4B or later (single-slot addressing) |
| Slot Width | 1 slot |
| Field Wiring Arm | 1771-WN |
| Configuration Software | RSNetWorx for DeviceNet; RSLinx for driver connection |
| Processor Communication | Block transfer with PLC-5 processor |
| Weight | Approx. 0.79 kg (1.75 lb) |
| Operating Temperature | 0 °C to 60 °C (32 °F to 140 °F) |
| Storage Temperature | -40 °C to 85 °C (-40 °F to 185 °F) |
| Relative Humidity | 5% to 95% non-condensing |
| Vibration / Shock | 2 g @ 10–500 Hz operating; 30 g operating shock |
| Agency Certification | UL Listed; CSA Certified; CE marked |
