Diagnostic Function; Input Disconnection Detection Function - Mitsubishi Electric MELSEC iQ-RX40NC6B Application User's Manual

1.4

Diagnostic Function

Input disconnection detection function

This function detects disconnections in input wiring.
When the input current is 20ms or higher, or 0.3mA/point or lower, a disconnection (no connection) is detected.
When the leakage current of the input device is 0.3mA/point or lower, connect a bleeder resistor (resistance value as a guide:
approximately 56k) in parallel near the input device.
When the external power supply is not supplied, the input disconnection detection function does not operate properly.
A problem has
A sensor is
occurred on B!
disconnected!
GX Works3
Operation of when an error is detected
When a disconnection occurs or no wiring is connected at an input terminal where "Input disconnection detection setting" is
set to "To detect", this function judges this state as a disconnection and 1 (Disconnection detected) is stored in 'Input
disconnection detection status' (Un\G2816).
When a disconnection is detected in the input module with diagnostic functions, an alarm (Input disconnection detection)
occurs. At this time, the input status depends on the value in "Input HOLD/CLEAR function setting".
The details of the alarm can be checked in the module diagnostics window of the engineering tool.
When a disconnection is detected, the ALM LED on the front side of the module turns on.
Sensor A
Disconnection or poor
contact
Sensor B
1 FUNCTIONS
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1.4 Diagnostic Function
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