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Anonymous Poster #1

4 to 20mA

06/30/2011 2:45 AM

Hi All,

How does 4 to 20mA works in a 2 wire 24vdc loop power, please provide circuit diagram for my reference. thanks

Regards
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PWSlack
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#1

Re: 4 to 20mA

06/30/2011 3:51 AM

This is chapter one in an instrumentation textbook. Amazon <usual disclaimer> perhaps?

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cuba_pete
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#2

Re: 4 to 20mA

06/30/2011 12:17 PM

By addings the loads? More loads makes more mA's.
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Tornado
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#3

Re: 4 to 20mA

06/30/2011 11:53 PM

Here are some articles that might help.

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erolf
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#4

Re: 4 to 20mA

06/30/2011 11:56 PM

24vdc is coming from DCS/PLC towards the transmitter. the circuit resistance of the transmitter will vary according to the change in PV which had sensed by the sensor and by ohms law, loop current is changed with rspect to circuit resistance. 4~20mA can be configured using HART communicator to set up what particular LRV and URV to which 4 and 20mA are assigned to.
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visaseller
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#5

Re: 4 to 20mA

09/07/2011 10:30 PM

supply 24vdc, load 250ohm (internal resintance of tranmitter) and u will get 4-20mA(0-5volt)
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cuba_pete (1); erolf (1); PWSlack (1); Tornado (1); visaseller (1)

Previous in Forum: Detector Raising Torque   Next in Forum: PLC to Honeywell/Yokagawa DCS

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