Opto-Isolated Digital I/O Signal Conditioning Boards for Small Form Factor Embedded Computer Systems

Arlington, Texas USA (PRWEB) May 02, 2012

WinSystems’ ISM-TRM-ISO-IN provides 24 lines of optically isolated and digitally debounced inputs to provide easy connections and signal conditioning from field wiring. The ISM-TRM-ISO-OUT provides 24 lines of optically isolated outputs. To interface with field wiring, the boards use 3.5mm pitch, industry-standard, pluggable connectors to insure reliable connection with easy removal and insertion.

Each input pair of the ISM-TRM-ISO-IN has configuration flexibility to support either an active high or active low signal from 5 to 30 volts. Every input line is optically isolated from the others and from the computer interface circuits. The isolation voltage rating between the input and output of the photocoupler device exceeds 2500V. Then each input line is wired to a contact bounce eliminator. Its purpose is the elimination of extraneous level changes that result when interfacing with mechanical contacts such as from switches or relays. This circuit removes bounce on both the make and break of a contact closure.

Each output line of the ISM-TRM-ISO-OUT is optically isolated from the embedded computers digital I/O interface circuit. The isolation voltage rating between the input and output of the photocoupler device exceeds 2500V. Each output has a NPN Darlington transistor pair with an integral clamp diode for switching inductive loads and transient suppression. The collector-emitter voltage can withstand up to 30 volts and each output is capable of sinking 500 mA of current required by most relays.

Both boards measure 3.6 x 3.8 inches (90 x 96mm) and have the same mounting hole pattern as PC/104 modules. The ISM-TRM-ISO-IN and ISM-TRM-ISO-OUT boards can be placed on the top or bottom of a PC/104 stack. These cards will also easily work with other computer form factors such as EPIC and EBX mounted on the PC/104 stack or as independent standalone signal conditioning modules for even more versatility.

Both ISM-TRM-ISO-IN and ISM-TRM-ISO-OUT signal conditioning modules are RoHS-compliant and can operate over an industrial temperature range of -40

About The Author

Ibrar Ayyub

Ibrar Ayyub is an experienced technical writer with a Master's degree in computer science from BZU Multan University. He has written for various industries, mainly home automation, and engineering. He has a clear and simple writing style and is skilled in using infographics and diagrams. He is a great researcher and is able to present information in a well-organized and logical manner.

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