Output Disconnection Detection Function - Mitsubishi Electric MELSEC iQ-RX40NC6B Application User's Manual

Output disconnection detection function

This function allows checking whether the load is disconnected or not when the output is off.
The minimum load current (at output ON) of when the disconnection detection function is used is 20ms or 3mA/point. If a load
lower than 20ms, or lower than 3mA/point is used, a disconnection may be detected erroneously at output OFF.
When the external power supply is not supplied, the disconnection detection function does not operate properly.
A valve is
disconnected!
GX Works3
Operation of when an error is detected
When a disconnection occurs or no wiring is connected at an output terminal where "Output disconnection detection setting"
is set to "Not detected", this function judges this state as a disconnection and 1 (Disconnection detected) is stored in 'Output
disconnection detection status'.
When a disconnection is detected in the output module with diagnostic functions, an alarm (Output disconnection detection)
occurs.
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 turns on.
When an inductive load is used, the module may not judge the wiring status correctly.
Refer to the following manual to take appropriate measure against the back EMF or configure the setting of
"Output disconnection detection disable time setting" using the engineering tool.
 MELSEC iQ-R I/O Module (With Diagnostic Functions) User's Manual (Startup)
1 FUNCTIONS
46
1.4 Diagnostic Function
A problem has
occurred on D!
Valve C
Disconnection or poor
contact
Valve D