Temperature and level sensing using Compactlogix L24

[roni]

Hi,
thanks for the supports to my programming needs.
i now have some questions
1. how we are configuring an analog input module (1769-IF8) to a 1796-L24 PLC to read 4-20ma. how would be the scaling? it is also needed to display in the PVP 400 PLC (keytype display).

Inputs:
am using thermocople omega m12jss, level sensor -Flowlline DL14(xx), TT - Automation direct FC-T1.
all readings shall be displayed on HMI.
there are three tanks, need to measure the temp and level. one tank has two thermocouple and the average of this could be read in PLC. other tanks have only one thermocouple. the output of thermo couple (4) and level sensor (2nos) given to PLC through analog input module 1769IF8. taken the outputs from plc and given to hmi for display.





could anyone help me out?

Thanks,
Roni.

 

[Tom Jenkins]

I always scale the card to read 4000 to 20000 (4-20 mA) which I believe is called engineering units. That made verifying field signals simple. Then I use the scale function (SCL)

http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1769-um002_-en-p.pdf

 

[roni]

Hi,
Thanks for the reply. I have went through the manual and got some idea of how the analog input is configured. But, i didnt get any idea to use SCP instruction in RSlogix Studio 5000 as an AOI. could you share some idea?


Thanks

 

[dginbuffalo]

Unzip this file and then import it to your add on instructions.

 

[roni]

Hi Dgi
many thanks for the zip file. its worked for me. I'm really a fresh programmer and firstly handling Analog modules. could you resolve how can we make a program in scp to measure temperature (4 difference values) and level (4 levels in a tank). The concept of scaling is not understood clearly.

Thanks in advance

 

[dginbuffalo]

Hi Dgi
many thanks for the zip file. its worked for me. I'm really a fresh programmer and firstly handling Analog modules. could you resolve how can we make a program in scp to measure temperature (4 difference values) and level (4 levels in a tank). The concept of scaling is not understood clearly.

Thanks in advance

You would add the SCP onto a rung that is always scanned. Follow Toms advice and set input up with scaling in "engineering units" which gives you 4000-20000 for 4-20mA.

In the SCP:

SCP: create an SCP control tag
input: Point this to your actual input channel tag
input min: 4000
input max: 20000
scaled min: 4mA engineering units (%, inches, meters,etc)
scaled max: 20mA engineering units (%, inches, meters,etc)
Output: create tag where you want scaled result to go

 

[roni]

Hi
thanks and thanks,
My pgm stuff is now working. i will update you all when i test this with PLC.