Analog Inputs; Voltage - Arcom RC210 Hardware Manual

Analog Inputs

The RC210 allows you to connect external analog devices and readback their value on command. This is typically used for
remote monitoring of such things as backup battery voltage, transmitter power, etc. There are 8 "meters" corresponding to the 8
Analog inputs. There are 6 meter faces you may define (this is explained in the Programming section) to any of these meters;
the selection of which properly scales the reading as well as properly "announcing" the meterface when readback of the value is
requested.
Volts
Amps
Watts
Degrees
MPH
Percent
NOTE: While these inputs are protected against reasonable overload conditions, care should nevertheless be taken never to apply a
.
voltage that exceeds +5.2v or any voltage that is below ground (negative)

Voltage

The major task involved in using a meter face is to design a sensor circuit that generates a sensor voltage in the approximate
range of 0 to 5 Vdc that is linearly related to actual physical measurement, such as a 12 volt battery. A simple device to
measure battery voltage would be a 10K potentiometer (pot). The actual voltages would be across the entire pot, and the sensor
voltage would be taken off the wiper. To adjust the pot correctly, it might be set to produce 2.5 volts output at the wiper when 20
volts is put across the entire 10K. Since the typical battery used in a repeater is unlikely to produce 20 volts, this would be a
safe "transducer" or sensor circuit for a typical 12 volt battery.
Or perhaps you'd like to monitor AC line voltage:
12