Practical Instrument Electronics 850 - Manual (Page 15)

Page 13
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10-50 mA Operation - The 10-50 mA control signal predated the
now common 4-20 mA signal. Many loops with 10-50 signal
have power supplies that run higher than 24 V DC.
SOURCE supplies from 0.000 to 52.000 mA with up to 40 V
DC compliance which has enough power to stroke valves.
2-Wire Transmitter Simulation limits the loop current passing
through it in the same manner as a 2-Wire transmitter with
loop power supplies up to 60 V DC.
READ measures from 0.000 to 52.000 mA from mA outputs
of controllers or to monitor the signal in a loop.
PWRM is POWER MEASURE which uses the internal loop
supply of the 850 to power up the transmitter while indicating
the current passing through the loop proportional to the input
of transmitter which is controlled by the output of the 850.
Operating Instructions
When simulating a 10-50 mA
2-Wire Transmitter in loops
with high voltage this section
of the calibrator may get
warm.