Mitsubishi MELSEC LJ71C24, User Manual

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15 TROUBLESHOOTING
15.3.18 Constant cycle transmission is not performed normally
Symptom Cause Corrective action MC
Non-
procedural
protocol
Bidirectional
protocol
Pre-
defined
• The setting value of the constant cycle
transmission is incorrect.
• Review the constant cycle transmission
setting.
• Does not operate in the
cycle time designated in
the constant cycle
transmission setting
• The cycle time is affected by some
causes.
• Remove the causes or designate the
cycle time anticipating the causes.
15.3.19 Condition agreement transmission is not performed normally
Symptom Cause Corrective action MC
Non-
procedural
protocol
Bidirectional
protocol
Pre-
defined
• The setting value of the condition
agreement transmission is incorrect.
• Review the condition agreement
transmission setting.
• Does not operate in the
cycle time designated in
condition agreement
transmission setting
• The cycle time is affected by some
causes.
• Remove the causes or designate the
cycle time anticipating the causes.
15.3.20 Data cannot be received due to by an interrupt program
Symptom Cause Corrective action MC
Non-
procedural
protocol
Bidirectional
protocol
Pre-
defined
• Interrupt issuance was not designated. • Designate interrupt issuance.
• Receiving by instruction other than
BUFRCVS.
• Use BUFRCVS instruction to receive
interrupt data.
• Cannot receive data with
the interrupt program
• "PLC Parameter" - "PLC System" - or
"Interrupt Pointer Setting" are not set on
the CPU module side, or the settings
are incorrect.
• Review "L Parameter Setting" - "PC
System" - "Interrupt Pointer Setting" on
the CPU module side
15.3.21 Data cannot be written to the flash ROM
Symptom Cause Corrective action MC
Non-
procedural
protocol
Bidirectional
protocol
Predefined
• Flash ROM write allow/prohibit was not
set to allow.
• Set flash ROM write allow/prohibit to
allow.
• Cannot write data to
Flash ROM • Setting modification is not enabled in the
switch settings by GX Works2.
• Set "Enable" in the switch setting by GX
Works2.
• The C24 was turned off during writing to
the flash ROM.
• Communication with GX Works2 was
interrupted during writing to the flash
ROM.
• Write the data again to the flash ROM.
• The data written to the
flash ROM are not valid. • When data is written to the
Programmable controller, C24 of the
"Intelligent Function Module" tab is not
set as a target memory on the "Online
Data Operation" screen.
• Check the procedure for writing data to
the flash ROM, and write the data to the
flash ROM again. (refer to Section 7.4.2)