Lj51Aw12D2 - Mitsubishi Electric MELSEC-Q Series User Manual

(5) The ALM LED on the master module is on.
Check that the transmission cables
(D G) are not disconnected.
Check the wiring of the terminal
blocks.
Execute the automatic address
detection function.
Check the existence of the slave
module.
9.3.2

LJ51AW12D2

(1) When the LINK LED does not turn on or flash after power-on
Check the power supply voltage of
the 24VDC external power supply.
Check the wiring of the terminal
blocks.
Check that the power cables (24V,
0V) are not short-circuited.
Check the total internal current
consumption of the entire system.
(2) The LINK LED on the master module does not flash.
Check that the LINK LED is turned
on.
64
Item
• Check that the entire transmission cables (D, G) are free from disconnection.
• Check that the cables have been crimped with proper pin assignment using link
connectors appropriate to the wire diameter.
• Check that the transmission cables (D, G) and power cables (24V, 0V) are
properly connected to the terminal block of the master module.
• Check that there is no incorrect wiring and screws have been tightened
sufficiently.
When creating a new system, adding or removing a slave module, or changing the
address of the slave module, execute the automatic address detection function.
After executing the automatic address detection function, check that the number of
slave modules and the address are consistent with those of the actual system.
If the LINK LED of the slave module is not flashing, check that there is no
disconnection, short-circuit, incorrect wiring, or poor contact in the transmission
cables around the slave module.
Item
Adjust the power supply voltage of the 24VDC external power supply to be within the
rated value (21.6 to 27.6VDC).
• Check that the 24VDC external power supply is properly connected to the terminal
block of the master module.
• Check that there is no short-circuit or incorrect wiring and screws have been
tightened sufficiently.
• Check that the power cables (24V, 0V) are not disconnected or short-circuited.
• When crimping the link connector, check that the pin assignment is correct.
Review the system configuration so that the total internal current consumption does
not exceed the rated output current of the power supply module.
Item
A malfunction has been detected in the master module hardware.
Reset the master module.
If the error occurs again, the module may be in failure. Please consult your local
Mitsubishi representative.
Action
Action
Action