Product Overview
The Allen-Bradley 1747-SN/B is a Remote I/O (RIO) scanner and Data Highway Plus (DH+) interface module for the SLC 500 platform. It lets an SLC processor talk to remotely located 1746 I/O chassis and other RIO-compatible devices, while also supporting DH+ networking. The /B suffix denotes Series B firmware.
Rockwell discontinued this module on 2024-03-31, with the 5069-AENTR named as the engineering replacement. For plants still running SLC 500, that means one thing: secure tested spares now, before a failure stops a line. Oil AutoTech supplies ready-to-ship 1747-SN/B modules for oil, gas and industrial automation sites worldwide.
Technical Specifications
| Parameter | Value |
|---|---|
| Product Type | Remote I/O Scanner / DH+ Network Interface Module |
| RIO Baud Rates | 57.6 / 115.2 / 230.4 Kbps |
| Logical Racks | Up to 4 (32 in / 32 out words) discrete |
| Block Transfer | Up to 64 words (Series B) |
| Max RIO Distance | 3048 m |
| DH+ Node Addressing | DIP switch |
| Backplane Current | 600 mA @ 5V DC; 90 mA @ 24V DC |
| Operating Temperature | 0 to 60 C |
| Mounting | Single SLC 500 chassis slot |
What These Specs Mean in Practice
The 3048 m RIO distance is the headline number. It lets you keep the SLC processor in a safe, climate-controlled panel while I/O racks sit out at the wellhead, compressor skid or tank farm. With up to four logical racks and 64-word block transfer, the scanner handles both discrete signals and analog or specialty data without extra hardware. DIP-switch DH+ addressing keeps node setup simple — no software tool required.
Maintenance and Reliability
From a maintenance engineer’s view, the 1747-SN/B is straightforward but not forgiving of hot work. It is not hot-swappable: never install, remove or wire it with power applied. Slot 0 stays reserved for the processor or a 1747-ASB adapter.
Inspect the module and terminal connections on a routine schedule, and confirm panel cooling keeps ambient temperature within 0 to 60 C. Because the unit is discontinued, treat every installed module as a critical spare. One failed scanner can idle an entire remote rack, so keeping a tested replacement on the shelf is the cheapest insurance your maintenance budget can buy. Fast dispatch, worldwide delivery means you are not waiting weeks when a line is down.
Replacement and Upgrade Path
Rockwell points to the 5069-AENTR as the engineering replacement. That move typically means a platform migration, new chassis and revised network architecture — a project, not a drop-in swap. If your SLC 500 line is still productive and you need uptime now, sourcing a 1747-SN/B is the practical route.
Before ordering, verify your chassis slot availability, RIO baud rate setting and DH+ node address. Our team offers hands-on technical selection help to match the module to your existing 1746 chassis and network layout. Contact Oil AutoTech today for pricing and availability.
Please verify current lifecycle status and availability with Oil AutoTech before ordering.
