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A Appendix
GX-series EtherCAT Slave Unit User’s Manual
A-3 Precautions with Connecting Two-wire DC Sensors
A
A-3-3 Relation between OFF Current of a Unit with DC Inputs and Sensor Leakage Current
IOFF ≥ Ileak
IOFF: OFF current of a Unit with DC inputs
Ileak: Sensor's leakage current
Connect a bleeder resistor if the sensor's leakage current is greater than the OFF current of a Unit with
DC inputs.
The bleeder resistor constant can be calculated using the following equation.
R ≤ (I
OFF × RIN + VF) / (Ileak - IOFF)
Power W ≥ (V
CC − VR)
2
/ R × 4 [allowable margin]
A-3-3 Relation between OFF Current of a Unit with DC Inputs and
Sensor Leakage Current