Deciphering overflow and underflow conditions coming from Analog inputs

Is there any way to ignore underflow and overflow signals coming from a PLC. Seems that tags don,t know how to decipher this.

Can you elaborate?

I am reading an input word from a Seimens S7-1200. When the field device is in active, below 4 ma underflow the input word goes negative. The tag displays a positive number outside of the engineering High limit set.

What datatype is the Ignition tag set as and what is the address (OPC Item Path) you used?

How can it be negative and postitive at the same time. Can you write the problem more clearly?

I have the data type set as float. In this specific case the item patch is set up as [Grinding PLC]IW96. as per instructions on connecting to a Seimens device.

IW96 is an unsigned type. If you're expecting to see negative values you need a signed type. Try II96, and see the address syntax reference here.

Further, if you're actually expecting a floating point value, then neither of these types are correct.


That worked. I changed the tag to integer and OPC to II96. Thank you very much.