Purchase now: Allen Bradley 1747-ASB Remote I/O Adapter
Purchase now: Atlantechdrives provides you the 1747-ASB, a highly reliable Remote I/O (RIO) Adapter Module engineered by Allen Bradley for the SLC 500 platform. In large-scale manufacturing environments, running thousands of individual wires from distributed sensors back to a central processor is cost-prohibitive and difficult to maintain. The 1747-ASB solves this architectural challenge by allowing an entire 1746 expansion chassis—filled with standard digital and analog I/O modules—to act as a remote slave node. It connects to the Allen Bradley Universal Remote I/O network, reporting directly to a master scanner such as a PLC-5, an SLC 5/04 equipped with a 1747-SN, or a modern ControlLogix system utilizing a 1756-DHRIO module.
Technical Specifications of the 1747-ASB
The 1747-ASB occupies slot 0 of the remote chassis and translates the high-speed RIO network data into the backplane logic required by the local I/O modules. It supports multiple baud rates to accommodate varying cable run distances.
- Part Number: 1747-ASB
- Module Type: Remote I/O (RIO) Adapter Module
- Compatible System: Allen Bradley SLC 500
- Network Protocol: Universal Remote I/O (RIO)
- Supported Baud Rates: 57.6 kbps, 115.2 kbps, 230.4 kbps
- Cable Requirement: Belden 9463 Twinaxial («Blue Hose»)
- Maximum Chassis Size: Up to 13 slots per adapter
- Backplane Current Draw: 375 mA at 5V DC
Expert Tips: DIP Switch Configuration
The most critical step in commissioning the 1747-ASB lies in its hardware configuration. Expert Tip: Unlike modern Ethernet adapters that are configured via software, the ASB relies entirely on physical DIP switches located directly on the printed circuit board. You must correctly set these switches to define the starting Logical Rack number, the starting Group number, and the network Baud Rate before installation. If your master scanner is broadcasting at 115.2 kbps and your ASB is defaulted to 57.6 kbps, the adapter will simply flash a red «FAULT» LED and never join the network. Always double-check your switch matrix against the OEM manual before sliding the module into the powered chassis.
Installation Advice: Blue Hose Termination
The Universal RIO network utilizes a linear daisy-chain topology. If your 1747-ASB is located at the physical end of the «Blue Hose» cable run, you must install a terminating resistor across the Line 1 and Line 2 terminals of the Phoenix connector. The value of this resistor is strictly dependent on your selected baud rate: use a 150-ohm (1/2 watt) resistor for 57.6k and 115.2k speeds, or an 82-ohm resistor for 230.4k. Failure to install this resistor will result in signal reflection, causing intermittent dropped I/O connections and frustrating machine downtime.
Frequently Asked Questions (FAQs)
Q: Can the 1747-ASB execute ladder logic?
A: No, it is purely a communication adapter. It gathers input data, sends it to the remote master CPU, receives output commands, and fires the output modules. It contains no user programming memory.
Q: Does it require its own power supply?
A: The 1747-ASB draws its 5V DC logic power from the chassis backplane. Therefore, the remote chassis must have its own dedicated power supply (like a 1746-P1, P2, or P4) installed in the left-most slot.
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To effectively manage remote I/O data through this adapter, ensure your system is equipped with a compatible 1747-SN Remote I/O Scanner module.
