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FF PID with 4-20ma AO

I am working on a project with DELTA-V Process Control.

all of Anlaog Inputs are FF based but for a few loops , We need to have regular 4-20ma AO (to control drive speed) based on level transmitters (which are FF). We are thinking to use FF to 4-20ma converters. But I need suggestions on what is the best method to deploy this Loop? Can i add standard AO card in the system and send the speed control to drive from there bases on the analog inputs from level transmitters on FF segments? Or should i use the signal

conver to just convert the FF AO to 4-20 ?

2 Replies

  • FF to 4-20 mA converter is one possible way. Traditional 4-20 mA AO card is another. But the best way to integrate a drive is using digital communication. Since the whole loop is digital it doesn't make sense to go analog 4-20 mA. Use a drive which supports PROFIBUS or PROFINET to send the signal that way. This way you also get the full diagnostics from the drive and configuration access. Learn more from this article: www.emerson.com/.../-digital-drive-en-37740.pdf
  • Jonas:
     
    I concur. We use Devicenet to communicate with our ABB and Allen Bradley dives. The information available on dive status, alerts etc. is invaluable for troubleshooting and servicing.
     
    Jim Armstrong