Interpreting Modbus to Voltage

[Pete_K]

I have what I think should be an easy problem to fix, but I am an ME whose controls experience unfortunately is confined to a former employer's proprietary language, and have only minimal experience with typical commercial PLC's

As part of a system we're developing, there is a purchased control system. This controller has a handful of discrete I/O for start/stop/fault, etc. and a whole bunch of operating information available over Modbus. This system will be tested in our test cell. The test cell data aq system is not very modern, and for the data we'd like to gather, it would be easiest brought into the test cell system as analog voltage.

So my first thought is that I could get a cheap PLC from Automation Direct, with Modbus protocal, and some analog voltage out modules, and be able to interpret the modbus info we're interested in into 0-10 V signals our test cell can read.

Is my approach do-able, or am I off base? Or is there a simpler solution to this?

Thanks in advance for the help.

 

[itsmoked]

That would work as long as you have no time response constraints. If you have time response constraints it may still work but you'd have to do some figuring. The AD CPUs have broadened lately. The Ethernet CLICKs are very nice to work with and I think they even have CPUs with analog out now. They definitely take in Modbus, both Ethernet and 485.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[Pete_K]

Thanks. Not too concerned with time response...we're not looking for quick transients, just want to be able to get steady state values into our system. The CLICK looks like an economical solution.