The RS485 Communications Authority

At this site you will find products and information on RS485, RS422, RS232, Ethernet, USB, and Fiber Optic Serial Communication Products. At R.E.Smith we carry a full line of serial converters, repeaters, multiplexers and line drivers, as well as micro-controlled I/O boards that can be networked over RS485 to distribute and capture data. Because our products are the result of meeting the needs of our customers, we are continually adding to and improving our product line. If you have a special application, we may already have a solution for you. 3.0KV Galvanic Isolation and -40C to 85C operating temperature range, is available on 95% of our product line.

We have recently introduced new high speed (10Mbps) 3.0KV Isolater Converters and Repeaters. We also have an extended distance product with 3.0KV Isolated High Voltage (12V) Differential Signal (IHVDS) that can communicate at distances up to 8+ miles using CAT-5 wire at 4800bps. At shorted distances: 57.6Kbps @ 3.75 miles and 115.2Kbps @ 3.0 miles. Also, we will be introducing a new line of Single Mode Fiber Optic Converters/Repeaters in the next 3-6 months.

Call 513-874-4796 for additional information.  Many of our newer products are not on our website at this time.


Check our USB & New Photos, Product CD Folders, or New Products links below for the Latest Product Information
Updated July 7, 2012 (Preferred Resolution 1024 X 768)

Click on the links below to navigate our site.

  "Let me spin a very large
RS485 network for you!"
The RS485 Communications Authority

Please call us at: 513-874-4796

Our 24-hour fax number is: 513-874-1236

We accept the following major credit cards for domestic and most international purchases:

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Or contact us by e-mail: contact

We incorporate many features into our product line that are not available on competitor's products.

    We design and produce our entire product line.  Fully automatic data direction control from DC to 115.2Kbps standard (faster available), at any communications specification, with very fast transition into receive mode after a character has been transmitted to avoid data collisions.  Very fast turn-on automatic transmit enable control (on the fly), to eliminate leading edge degradation for reliable cascading of multiple units.   Bit-by-bit timing eliminates character oriented time delays without jumper settings ("self-tuning" to any data/baud rate and/or any number of bits/character with all formats supported, including data highway plus, DH+, DH, etc.).   Your operating system, or other devices on your RS485/RS422 network, might limit the communications speed; however, our converters and repeaters won't.  Many of our products incorporate; superior multi-stage transient protection (without limiting speed or loading), LED indicators, bias/termination/test jumpers, dual isolation (for inline repeaters) to insure correct installation/superior performance, and removable screw terminal strips.

     Our "Industrial Strength" products operate from 9-35VDC, with 3KV Galvanic Isolation.  At this time about 95% of our entire product line has an extended operating temperature range of -40C to 85C.  We have units that will extend the distance of RS485/RS422 communications, with and without repeaters/extenders, products to implement very large RS485/RS422 networks.  We are working on units (converters, repeaters and I/O products) with power and data over standard CAT-5 cables, for multi-drop and/or event-driven networks.  MODBUS compatible I/O units will be available soon. Our new S232DC will allow 4 RS232 keypads to be connected into a single RS232 port with identification of the keyboard source.

     Our products are at the South Pole, at the bottom of the sea, at the edge of space, and everywhere in between.  If you think you have found a better converter, repeater, or multi-repeater (home-run data distributor) please let us know.  It won't be the best for long.  Technical assistance and system design help available (no charge).   See USB & New Photos below for information/photos for many of our newer products.

Ask us about RS485TURBO(extended speed and distance)

RS485/RS422/RS232 Networks as God Intended Them to Be

        Donna Schaller-Smith, October 26, 1947 to February 4, 2006         Mandy,  January 14, 1983 to May 13, 1997