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Digital Inputs

All MFR-series modules provide eight digital input channels. Optocouplers galvanically isolate the inputs from the internal logic and from one another, improving interference immunity in industrial environments.

Technical Data

ParameterValueNote
Nominal Voltage24 VDCOperating range 0–30 VDC
Input Currentapprox. 4 mAat 24 VDC
Internal ResistanceRi5kΩ
Switching Thresholdapprox. 4 VDCHigh level detected above 4 V
Polarity ProtectionYesvia optocoupler diode

Pin Assignment

Each fully isolated input channel has its own positive and negative terminal pair.

BitTerminalDescription
0I0+ / I0-Input bit 0
1I1+ / I1-Input bit 1
2I2+ / I2-Input bit 2
3I3+ / I3-Input bit 3
4I4+ / I4-Input bit 4
5I5+ / I5-Input bit 5
6I6+ / I6-Input bit 6
7I7+ / I7-Input bit 7

Logic & Wiring

The inputs are active-high. A nominal voltage difference of 24 V between Ix+ and Ix- is interpreted as logic 1.

  • Common ground: Bridge all Ix- terminals and connect them to ground.
  • Isolated operation: Use both conductors for each sensor.