Scaling in C-More

Eric Nelson

Lifetime Supporting Member + Moderator
Eric Nelson
Join Date
Apr 2002
Location
Randolph, NJ
Posts
4,346
My customer needs to temporarily change the displayed value on his HMI from Fahrenheit to Celsius for a week. I did not write the PLC program, and I see a lot of BCD to Real to Decimal conversions in the program (DL205). Instead of trying to decipher where to make the conversion in the PLC, I thought maybe I could just scale the value in the HMI.

So, can I simply scale it like I show in the attached screenshot?

🍻

-Eric

cmorescaling.jpg
 
Just make sure that the data type of the C-More tag is the same as the data type used in the PLC's V-memory address.
If you get it wrong, you can't change the data type of a C-More tag while it is being used anywhere in the project. You have to delete all instances of the tag on any screens or in the event manager in order to change the data type.
 
With a 4 digit display set to 1 digit fractional, you will need your scaling set to:
PLC value point 1: 320 Display value: 0
PLC value point 2: 2120 Display value: 1000

See screenshot.

CMoreScaling.png
 
Steve Bailey said:
Just make sure that the data type of the C-More tag is the same as the data type used in the PLC's V-memory address.
If you get it wrong, you can't change the data type of a C-More tag while it is being used anywhere in the project. You have to delete all instances of the tag on any screens or in the event manager in order to change the data type.
Click to expand...
Yeah, I've been burned by this before :D

Everything is currently correct and working. I just need to make the value display in °C instead of the current °F. There are 30 tanks (metal treatment facility), but they just need me to change one to meet a customer's spec.

I think eventually they'll want this for all tanks. I'll do that in the PLC and give them a toggle button to chose between F and C. They just need a 'quick fix' for this one job.

🍻

-Eric
 
Also, thanks for making me look at the 'General' tab again. I don't want to forget to lower the max range value from 200 to 93.

🍻

-Eric
 
An additional possibility is to make two controls for each tag location, one displaying and controlling in Farenheit and the other in Celsius. Create a toggle button controling an internal bit which is used to control the visibility of the controls. Then overlay them.
 
I like this approach Bernie! I only have the uploaded PLC program (no tags, comments), and it would take some time to reverse engineer. It will definitely be easier if I just do the toggle in the HMI. :cool:

🍻

-Eric
 

Similar Topics

D
Scaling temp. data in C-More Line Trend Graph
I'm having an scaling issue using an F0-04THM module card with a Directsoft D0-05DR PLC. My issue is this; the temp data in the PLC has one...
Replies
13
Views
2,812
Brian123
B
H
Logic for scaling more than two coordinates required
Hi I want to generate a code for a scaling of x,y table,like what we do in analog input scaling of PLC's. Normally for analog inputs we have two...
2
Replies
19
Views
5,210
hajdeen82
H
R
1746-NI8 scaling problems
Hi, having some issues with scalings (SCP commands) with some Vegapuls 65 guided wave radar level transmitters. I've set the min/max in the...
Replies
5
Views
160
Robb B
R
C
Tank water level scaling in PLC
I want to measure the tank level and get the sensor output to the PLC. Below are the details : Tank Height =0 - 3m, the sensor is stalled 0,2m...
2
Replies
15
Views
623
colesha
C
R
Allen-Bradley Analogue Input 1756-IF16 Scaling
Hi, I have a ControlLogix system with 1756-IF16 analogue inputs. I can't scale the inputs at the card as there is a requirement to facilitate...
Replies
14
Views
365
Rich0147
R
Back
Top Bottom