Drop in mA .

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JM RAO Participant Join Date: Jan 2009 Posts: 2 Good Answers: 1	Drop in mA . 01/01/2009 5:46 AM
	We have a Siemens 393 controller. Recently DCS Emerson V9.4 has been installed. Analog input has been connected in series with the DCS. 24 V supplied from DCS analog input card.My problem is that, mA is dropped in DCS end and remaining normal at controller end. kindly suggest how to overcome this problem.
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caramba Guru Join Date: Jan 2008 Location: Kazakhstan Posts: 753 Good Answers: 8	#1 Re: Drop in mA . 01/01/2009 4:04 PM
	I'm supposing you've been faced either short cut before your DCS or lack of needed power from analog current regulator. For first case check your wiring's parameters or apply an analog signal conditioner for latter.
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Anonymous Poster	#2 In reply to #1 Re: Drop in mA . 01/02/2009 6:18 AM
	Power section offering power to internal circuitry may have problem. Because of which different circuital nodes may not develop desired voltage resulting in loading problem.........
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kioclbfu Participant Join Date: Jan 2009 Posts: 2	#3 In reply to #1 Re: Drop in mA . 01/02/2009 10:22 PM
	This type of problems occur sometimes due to impedence mismatch between the transducer and dcs I/o card.Provide a high impedence isolator between the transducer and DCS I/O card.IT MAY SOLVE YOUR PROBLEM
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steve_y Active Contributor Join Date: Jul 2008 Location: France Posts: 12	#4 Re: Drop in mA . 01/07/2009 10:48 AM
	What is the maximum load (in ohms) that the controller can accept ? It might be fairly low and the additional input impedance of the AI card may mean you are now exceeding the maximum Steve www.mtl-inst.com __________________ Bad English is Bad for Business
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find2am Commentator Join Date: Jun 2008 Location: India Posts: 95 Good Answers: 1	#5 Re: Drop in mA . 01/10/2009 2:06 PM
	where the controller end is connected to the loop with dcs and analog input can u please give details
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Anonymous Poster (1); caramba (1); find2am (1); kioclbfu (1); steve_y (1)

You might be interested in: Distributed Control Systems (DCS)

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