Sign in to follow this  
Followers 0
auto_cj

scale 0-20000 using 4-20mA input suing SCL(194)

6 posts in this topic

I have a input that is 0-20000 ppm, How Do I scale it and then Store it correctly in memory? Thank you very much Collin

Share this post


Link to post
Share on other sites
If it was me, I would configure my input card for Scaled-for-PID, in advance I/O config. Then my raw values would be 0-16383 Which means 4 ma = 0 raw unit 20 ma = 16383 raw units Which also means 16383 raw units is your units 20000 ppm or 1.22077 scaled. To use the SCL function you multi that 1.22077 by 1,000 your value in the function block would be 1220 or I would round up 1221 So when the raw units is 16383, the SCL will multi it by 1.221 and your ppm units will read (20015.853) EDIT: Crap....I just told you how to do it in Allen Bradley...I thought I was reading in the Allen Bradley forum....sorry about that....

Share this post


Link to post
Share on other sites
First off which PLC? The SCL and SCL2 functions are binary to BCD - the SCL3 function is BCD to binary. Is your input binary or BCD? That is why the PLC model is important. Here is a link to a 'scale with parameters' routine that may be helpful.

Share this post


Link to post
Share on other sites
Hi Sorry for omitting so much CJ1M CPU13 Using a AD081-V1 card, resolution = 8000 signal is a 4-20mA input, I want it to be 0-20000 scaled stored in a DM location. I tried using SCL, Which is what Omron suggests to use to do scaling on this Card, but to no avail Thanks!

Share this post


Link to post
Share on other sites
Apparently I omitted putting in the link - scale with parameters http://forums.mrplc.com/index.php?autocom=downloads&showfile=523 It should put you in the right direction. Another method I often use is floating point maths. Edited by BobB

Share this post


Link to post
Share on other sites
Simply scale to 0-8000, then multiply the result by 2.5

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0