User`s manual

NexSens Technology, Inc.
iSIC User‟s Manual 48
Loop Powered 4-20mA Sensors
Connect loop powered 4-20 mA sensors to the internal digital analog terminal strip. A diagram
of this is shown below:
Pins AD0 through AD7 can all be used for connecting 4-20 mA sensors. Eight loop powered 4-20
mA sensors can be connected at the same time using these pins on the analog terminal strip.
It is necessary for a sense resistor to be added into the wiring for each sensor to convert the
current signal into a voltage signal. For your convenience, four 56 resistors are included with
the iSIC. The included resistors have a 1% accuracy. It is recommended you check the
documentation for your particular sensor to find the exact resistor requirements.
Note: GND and AGND are wired together because loop powered sensors require both digital and
analog signals.