The Industrial Raspberry Pi Forum

Hello,
I am new to revolution pi and i want to read an Temp/Humidity 4-20mA sensor, in piCtory i changed the "Input1Range" and "Input2Range" to 4-20 mA ... and i installed a jumper between * and + , pin 26 to 28 ... but the "In" Red led keep blinking and when i write piTest command "piTest -r InputValue_1" to read the value .. i have just "2 Byte-Value of InputValue_1: 55937 dez (=da81 hex)" and its constant over time...

please, how to connect a simple 4-20 mA sensor to Revpi AIO, maybe someone could send me a wiring diagram because i tried all the combinations and Red Led on the module keep blinking..
i tried an other 0-10v sensor (it's a CO2 sensor) and i works Fine ! but for 4-20 mA ... it's a nightmare :/

Thank You all

You need to supply the sensor on the "+" side from a 24V Supply (the measuring inputs actually have an internal resistor to ground where the current is converted into a voltage that is read back then).
It's not sufficient to hook the 2 sensor wires to the 2 inputs cage clamps only.

If the current is slightly below 4mA due to a sensor offset you may also get the warning.