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July 2011

A-B Remote I/O Interfaces

Smart A-B RIO Interface

ow cost interfaces
to Allen-Bradley Remote I/O
Drive A-B RIO as a Master
Respond to A-B RIO as a Slave

An internal interface for our Smart SoftPLC and Smart Gateway products is now available, providing the lowest cost connectivity to Allen-Bradley Remote I/O (eg: 1771, 1747 (SLC-500), Flex, and other compatible networks).

Example application using the Master interface:
Upgrade existing A-B PLC systems without replacing or re-wiring the I/O - with SoftPLC you can even re-use most (and many times all) of the existing logic and program documentation!

Learn More about A-B Upgrade Options

Example applications using the Slave interface:

  • Gateway between an A-B PLC and other industrial networks such as ModbusTCP, Profibus, Modbus RTU/ASCII and many others

  • Add SoftPLC's Tealware I/O to an existing A-B PLC system

Contact us for pricing or more information!

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Application Story: PLC-2 Upgrade

A packaging machine was still using a PLC-2/20 based system for its controls.  The customer wanted to connect the machine to a new plant-wide Ethernet.  A number of options were considered, including adding communication modules and using a Gateway or HMI, or converting to a PLC-5 or ControlLogix.  But the best option, and the one selected, was to convert the PLC-2/20 to a Smart SoftPLC, leaving the existing 2 racks of 1771 I/O in place.

Original PLC-2 system

The process entailed uploading the existing logic using TOPDOC PLC-2 (the customer had no PLC-2 programming software) and converting it using SoftPLC's automated utility.  All rungs converted 100%.

On the hardware side, the PLC-2/20 processor was replaced by a Smart SoftPLC with an A-B RIO interface.  The 2 rack-based local I/O adapters (1771-AL) Smart Backplane3were replaced with remote I/O adapters (1771-ASB purchased at very low cost through the surplus market). Then, standard Belden "blue hose" cable was used to connect the SoftPLC to the I/O racks.

The PLC-2 I/O included a  Gray Code Encoder module (1771-DKC) which transitions too fast to work properly on A-B's slow RIO network.  So a SoftPLC Tealware TTL module was used for this I/O, mounted directly on the Smart SoftPLC using its local Backplane3 interface.

Cost?  Under $1900!
(including the two 1771-ASB modules)

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