Force analog input in step7

I work on CPU314 and step7.I can force digital input and output in step7 but I couldn't force analog input.Does anyone know why?

Hi.

First, you need to know that the block FC105 "SCALE" taka a Integer value (convertion of A/D) in the input "IN" and convert into REAL Value. For example: if you have a 4 to 20 ma level meter, that have a range betwind 0 to 1000 Lts

4ma----->0Lts--------->0 INT (Input of block) Unipolar!!
12ma---->500Lts------->13824 INT
20ma---->1000Lts------>27648 INT

Now you know how to force the analog input I hope!!

Kind reagards

You need to be more specific in what you are trying to do...


If you are trying to write to an analog input, your value gets overwritten on every scan by the PLC. You should change your code to a temporary variable, like MWxxx, for troubleshooting.