Does someone knows a product that can receive some analog(4-20mA) and digital inputs, multiplex them, send them trough optical fibre and at the other end of the fiber, reconvert them in analog and digital signals.
First step is to convert your inputs to digital and then multiplex them over a single serial port, RS-232 or RS-485. The conversion back and forth to fiber is straightforward. There are a lot of converters to do this on the market.
You can do this with a wide variety of programmable logic controllers as well.
For fiber, you should plan on a dedicated pair of fibers.
As far as the comms part of the question, I used a pair of modules from Phoenix Digital Corp. for fiber-based communications from PLCs to Remote I/O racks on an A-B PLC-5 system. As far as a stand-alone system goes with I/O at either end, I don't know. From what I understand, Phoenix Digital makes products to serve a wide variety of industrial control platforms, but the user has to supply the intelligence at either end to convert to/from I/O. Check out their website at
A company called Eurotherm makes a product called Link. It uses fiber optic cables to connect various modules together. I have used it a number of times. They have analog modules, digital modules that have both inputs and outputs. The Link I style uses 24Vdc as a power supply. The modules not only can handle the analog (5 ins 1 out) and digital (12 in or out) signals but also are fully programable computers with a complete set of function blocks available and can operate as a fully functional control system if you want. The modules are fairly small and mount on DIN rail. They also have a Link II system which is much more powerful and uses 120Vac and plug-in digital (16 in or outs) and analog (8 in 2 out) cards. Call 800-279-0102 for more information.