Need a lot more info.
What PLC are you using?
What Analog card are you using?
What type of signal? 4-20, 1-5v, 0-10v?
You need to provide at least two more pieces of information. First the minimum and maximum raw or proportional values. Second, the minimum and maximum values of pounds corresponding to those two raw values. Ok, I guess that's four pieces of information.
That will allow someone to give you an example of how to perform the scaling operation. With information requested by Bullzi, someone can come up with how to do it with the equipment you're using.
1769-??? (which one? it does matter)
And PLC?
---------------------------------------------From the manual that I looked at for the 1769 Analog I/O your range is:
0V = 0 Counts
10V = 31206 Counts
So if you are using a CompactLogix PLC you can download the SCLP AOI from the Rockwell website and use that. If you are using a ML1500 you will have the SCLP instruction available to you.
These instructions will scale your 0-31206 to 5-100lbs you are asking for.
Mickey:
model# 1769 Allen Bradley (Analog Input card) IF4
0-10 volts