analog input programming

[aryautomation]

I am trying to measure a DC current going through a DC motor. I have installed mlogix1500 with an analog input card and 0-10 volts current transducer. This is the first time I am programming ml1500 analog input, I am not sure what I need to put in the logic diagram to capture the data. Any help will be appreciated.

 

[Mickey]

Questions:
What analog input card are you using ( Module Cat no.)?
What does the 0-10 volts from your current transducer represent?
i.e.
0 volts=0amps
10 volts= 10amps
Or?

 

[aryautomation]

Sorry, I am using current output of the transducer.
analog card is 1769-IF4
4 ma is equal to 0 VDC
20 ma is equal to 40 VDC

 

[Mickey]

See Pictures below. I used engineering units for the data format, but there are other formats ( you decide whats best for you.
This gives:
4ma=4000 (raw data)
20ma=20000 (raw data)
You said in the first post you wanted current but in the last post you stated voltage? The scaling instruction will be the same, you might have to change the min/max values.

 

[aryautomation]

thanks a lot, that was a great help

 

[Mickey]

Your Welcome

 

[aryautomation]

I put the instruction that you gave me. I am getting a warning that I do not understand.
SCP floating point operands are only valid for Micrologix 1500LRP/LSP series C FRN7 or higher....
What that means? I am using micrologix 1500 with LRP series C.

 

[Mickey]

It means if you didn't have that series controller floating point data
files would not be supported by that instruction. But sence you do have
series C then just ignore the warning. Note warning not error. It will work.

See AB knowledgebase I.D.27698 at link below. You may have to register (its free)

http://rockwellautomation.custhelp....GV4dD1TQ1AgaW5zdHVjdGlvbg**&p_li=&p_topview=1

 

[aryautomation]

thanks a lot

 

[Mickey]

Your Welcome