Modicon Math Problem

[snydl0ga]

I am assisting on a multiplant support team. Our plants have different versions of Modicon PLCs. Some are Quantum 424 & 486 and some are 984B. We are running a enterprise software package for data collection and these plants are having an issue around doing math with Negative numbers.

My questions are:
1) Is this a common issue in Modicon?
2) Are there upgrades possible or modules we can add on to accomplish math with neg numbers?

Lance

 

[Macbeth]

I bet all of your math is done in Intergers. If you are trying to do all of your scaling in ths PLC then I feel as you are better off doing it in Floating point Math EMTH blocks.