Model PD690 Universal Process Meter
Instruction Manual
4-20 mA Output
The 4-20 mA output from the meter can either be powered from the
meter’s internal transmitter power supply, (if it is not being used to
power the input loop), or by an external power supply as the follow-
ing diagrams illustrate:
Figure 10: Meter Powering 4-20 mA Output Loop
Figure 11: External Power Supply Powering 4-20 mA
Output Loop
If the output loop is powered by an external supply, the loop
power supply must be turned on before the meter is turned
on. Otherwise, the output loop signal may be incorrect.
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Signal
Input
Meter, Recorder
Controller, etc.
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Signal
Input
Loop
Power Supply
Meter, Recorder
Controller, etc.
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CM
