MC Technologies MC100 - Current Input 0 - 20 Ma Rx; ISO; Current Outputs 0 - 20 Ma Tx

MC100
Mobile programmable gateway
MC Technologies GmbH, Kabelkamp 2, 30179 Hannover, Germany
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Current input 0 - 20mA Rx / ISO
The analog current inputs of the MC100 SensorBox have two operating modes.
1. Supply of a current - current from the sensor - sensor with own power supply
2. Low side shunt - with power supply for the sensor
11.7.3.1 Supply of a current - current from the sensor
The connected sensor has its own power supply and a current output with a current of
20mA.
The sensor is connected to + and – of Rx.
Port
Description
+
Positive connection input, current output of the sensor
-
Negative connection Input, sensor ground
11.7.3.2 Low Side Shunt - power supply for the sensor
It is possible both to supply the sensor with power and to measure the current it draws over
the same two wires. The sensor will be powered from the MC100 SensorBox. A voltage is
applied to the terminals + and – of 4-20 mA ISO for this purpose. Connect the sensor to +
and – of 4-20 mA ISO.
Function: Reading the current inputs
Port
Parameter
Read
Write
Path
+,-
Rx
Value
x
/sys/sensor_carrier_board/adcinputs/adcinput1/value
+,-
ISO
Value
x
/sys/sensor_carrier_board/adcinputs/adcinput0/value
Example: Read current at ADC input +,- Rx
Command: cat /sys/sensor_carrier_board/adcinputs/adcinput1/value
Response: e.g. 1500
Note: Conversion to mA
Formula: Current in mA = Value * 20 / 3000
Example: Value = 1500 corresponds to 10mA
Current outputs 0 - 20mA Tx
Function: Output of a current (v1.0.8 and older)
Port
Parameter
Read
Write
Path
+,- Tx
Value
x
/sys/sensor_carrier_board/adcoutputs/adcoutput/value
Example: Output of 6mA at OI1
Command: echo 6000 > /sys/sensor_carrier_board/adcoutputs/adcoutput/value
Response: none