Signal processing how to transfere information using MOSBUS format

The problem is not the availability of a data acquisition card. Mathcad 15 supports user defined DLLs, so it's certainly possible to write an interface that would allow Mathcad to read from a data acquisition card. The problem is that Mathcad is simply the wrong tool to do that in a continuous manner (which, since you are asking about 4-20 mA and Modbus, is what I assume you want to do). Let's suppose you had such a DLL that defines a function that reads from the card. You call it, it reads the latest value, displays in on a graph, and then the worksheet stops. OK, so you put a loop in the DLL so that it continues to read. Then Mathcad calls the DLL, the DLL never exits, and Mathcad is hung. OK, so what about putting the function in a Mathcad loop? Basically, the same problem. In either case you could set the loop to run for a set umber of iterations (or time), but you would not see any of the values until the end, when you see them all, and then the worksheet stops. There's not a lot of point in a process monitoring system where you don't see anything until the process has ended (assuming it is even a batch process that actually does end). As far as a process control system goes, it's obviously a complete non-starter. There is simply no way to make Mathcad continuously collect data and do other calculations or display that data at the same time. It's not what Mathcad does.

If you really need Mathcad for some reason the only option you would have to to write an external program that reads from the card and calls Mathcad via the automation interface to do calculations and get the results back. That's going to be kind of slow though.

If real time process monitoring or control is not what you want to do, please clarify what you do want to do.

If real time process monitoring or control is what you want to do, please specify why you think you need Mathcad to be a part of that. There still won't be any good solution using Mathcad, but maybe someone can suggest an alternative approach.