4-20mA TO propotional valve control

tsaks89

Member
T
Join Date
May 2019
Location
Greece
Posts
15
Hello all!


I am new here. I think this site is like a treasure for me...


Now to my issue. I am using Wago plc and i am working on codesys but i am a newbie. I have a project in which my input is a joystick 4-12-20 ma. I would like to control 2 solenoids with range 400-1200ma. One solenoid in on when i have 4-11 ma (4->1200 and 11->400) and the other when i have 13-20 ma (13->400 and 20->1200). My I/Os are 750-455 and 750-632. I tried many way through manual and i can't control my output. I tried also with lin_trafo but nothing. I am doing something wrong.



Is there any STL or FBD example available?


Thank you in advance!
 
geniusintraining said:
Hello and welcome,

I have never used a 632 but there is a lot of information on Youtube,

https://www.youtube.com/watch?v=CR4ZFUt1exs

It would also help if you posted your logic if you can then maybe someone could help in more detail
Click to expand...




Thank you for your reply!
My issue is that i can't make those two to cooperate.I don't know how. In this video is more simple because inputs are controlled through codesys program.
 
Do you want the valve to follow the position of the joystick?

That is almost impossible if you do not have a feedback on the position of the valve.

Many proportional valves can be equipped with an additional module that transmits the position of the valve for example using 4-20 mA, then you would only have to compare the two analog inputs and open or close until they equalize, with a small tolerance to avoid oscillations.
 
It looks like a falling output to solenoid 1 from 4 to 11 ma input and a rising output to solenoid 2 from 13 to 20 ma input. What do you want to output to solenoid 1 above 11 ma input and similarly what is output to solenoid 2 below 13 ma input?I

You will end up with two scaling type functions within the two control ranges with probably a fixed output outside of the ranges.


I don't use Codesys so I can't give examples.
 
I believe this is what you want to do....
https://youtu.be/dH3M_98l4io
(no sound. I'm feeling lazy)

*** EDIT ***
*** THERE IS ACTUALLY AN ERROR IN THIS PROGRAM BUT SURPRISINGLY IT DOES WORK. I'LL DO A QUICK FOLLOW UP WHERE I FIX THE ERROR ***
 
Last edited:
ndzied1 said:
I believe this is what you want to do....
https://youtu.be/dH3M_98l4io
(no sound. I'm feeling lazy)

*** EDIT ***
*** THERE IS ACTUALLY AN ERROR IN THIS PROGRAM BUT SURPRISINGLY IT DOES WORK. I'LL DO A QUICK FOLLOW UP WHERE I FIX THE ERROR ***
Click to expand...


Thank you all and especially ndzied! I will try to run the program to codesys..Otherwise i will try on cokpit..Reverting with results!


lfe:
No mandatory to have feedback from valve.I would like to have a 4-20ma input and a designated output (scaling)


bernie:
Me also..first time working on codesys with 4-20ma...
 
So for example i have 4-20ma I/O. I will name first analog input as AI1. How could i connect AI1 with GVL.JOYSTICK? How codesys could translate AI input into Real value? Also valve output would be CW value(current output)?How i could make these connections??


Thanks!
 
Not sure how Wago does addressing of their hardware I/O points. Guessing there is a video of this.

I used a global variable file because I was only running a simulation and did not have any real hardware. You can just put the tags for your hardware I/O points in the program where I have the global variable s (GVL...). You might have to adjust the scaling parameters to match what your actual controller uses. but in general, you would just put AI1 everywhere where my program has GVL.JOYSTICK.
 
Good morning ALL!


i am going to finish the program with the help of ndzied1.
I made the input from real 0-32764 to ma through lIN_TRAFO.
The system is working normally i have Word output but i don't have real value at I/O output. Any idea?
 

Similar Topics

J
4-20mA loop grounding
Hi all, I'm connecting several 4-20mA sensors together in parallel (only one shown below) The enclosure is ABS plastic with metal backplate DAQ...
Replies
5
Views
272
Jenny8711
J
A
Looking for a 4 or 8-channel converter for 4-20mA inputs and 0-135Ohm outputs
Problem: Our PLC can only output 4-20mA, but the actuators it needs to control, modulate based on a 0-135Ohm signal. Buying 4 or 8 individual...
Replies
7
Views
275
AdaptnOvercome
A
D
4-20ma isolator.
What's your go to 4-20ma isolator. I've got some 4 wire 4-20ma from several flow meters and scales that I would like to isolate before it gets to...
Replies
10
Views
1,683
jdbrandt
J
S
4-20mA analog output from DCS
Hi, I need to read three 4-20mA signals from a DCS(ABB) in a remote 6 channel analog input module with RS485 modbus port. When I connected...
Replies
2
Views
484
danw
danw
V
4-20ma loops with multiple supply's on different inputs can you the commons together
Hello this is my first post. Looking forward to being more involved in this community to learn and hopefully help others. Any help or guidance...
Replies
7
Views
785
lfe
L
Back
Top Bottom