Scale a 4 to 20 mA input

userxyz

Member
Join Date
May 2002
Location
any
Posts
2,768
Right,

I wanna scale a 4-20mA on a siemens plc

I have 0 to 27648 on the analogue input

so what I do is:

I Devide the input with 27648. So at 20 mA I have 1 as result.

I multiply is with a range of 16 (4 to 20mA).

After that I Add + 4 (Offset)

Then I have scales 0 to 27648 to 4-20mA

How do u guys do this?
 
What you have described is the quickest way to do it. The alternative is to use FC105 (scale) block supplied by siemens and pass parameters to perform the scaling you require.
 
Combo,

For PLCs that do not have a SCALE function, and even sometimes if they do but I need intermediate results for use elsewhere, then I use these equations:

Slope = (Scaled Maximum - Scaled Minimum) / (Input Maximum - Input Minimum)
Offset = Scaled Minimum - (Input Minimum X Slope)
Scaled Value = (Input Value X Slope) + Offset
 

Similar Topics

Hi, I'm using a Micrologix1500 and it doesnt have the SCP (Scale with parameters) block. I have a 1769-IF8 analog module and need read the inputs...
Replies
10
Views
3,717
Please help me... Is there any possible way to use AB IR4-1762 module for analog input scaling....?
Replies
1
Views
1,166
This is a case where technology is working against us. My customer needs to directly insert weigh scale data into a form. The weigh scale...
Replies
2
Views
1,749
Hello I m using Unity Pro XL. I want to scale my analog inputs. I configured the Analog Input Module as 0-4 mA and 0-10 V . What is the way...
Replies
2
Views
2,971
I'm going to be using a Micrologix 1200 to scale an 4-20mA analog input from a weighing scale and want to output this to an 4-20mA analog signal...
Replies
12
Views
11,354
Back
Top Bottom