4-6
IM CA71-E
4.2.4
Using As 24-V Loop Power Supply
A maximum load current of 22 mA can be drawn from the calibrator by
selecting the 30 V range and setting the sourced voltage to 24 V. With
this function, you can use the calibrator as a loop power supply in place
of the distributor in a two-wire loop, as shown in the following figure.
Thus, you can measure a 4–20 mA current signal. Using the supplied
terminal adapter (P/N: 99021) makes it easy to wire the calibrator for
this application.
NOTE
Since the function discussed above requires a significant amount of DC cur-
rent (22 mA), operation on batteries will reduce the battery life considerably. To
avoid this problem, operate the calibrator on the AC adapter. In this applica-
tion, no source output other than 24 V can be taken at the same time.
CA71
AC adapter
24V
4-20 mA
Input
A
Two-wire
transmitter
L mA
H L
MEASURE
SOURCE
24 V output
Using As a Loop Power Supply
4.2 Sourcing DC Voltage, DC Current or SINK Current Signal
