Ab plc 5/15 scale/maths

[Til123 0]

Hi, can anyone help me with the correct equation please? I have a 0-10 v analog input scaled @ 0-10, however I need the hmi to read

0.001 @ 2.5 v, 0.01 @3.5v5v, 0.1 @ 4.5v, 1.0@5.5v, 10@6.5v, 100@7.5v, 1000@8.5v.

This is linear starting from2.5v through to 8.5v

Edited 2 Mar 2017 by Til123
New info

[pcmccartney1 141]

Til123,

 

Please refrain form double positing.  Refer back to your original post and Mickey's reply.  He gave you everything you needed.

To better visualize this, plot your points in excel and then view in a graph.  What you will notice is that the curve is basically a combination of three fairly straight lines.  You could then apply Mickey's suggestion in three separate CPT functions, but executed based upon limits on the low and high scale values of each "linear" section of the curve.