Mitsubishi Electric MELSEC Q Series User Manual page 227

11 TROUBLESHOOTING
Error Error
code detail
1 Data is not written to the flash ROM.
1901
A sum check error occurred while data
2
is written to the flash ROM.
Over 25 times flash ROM write and
parameter initialization were executed
1902 1
from the sequence program in power
supply ON.
The parameter initialization is requested
1903 1
in PLC READY ON.
The PLC CPU has an error.
1904 1
(Stop error)
(3) Interface errors (1900 to 1999)
Error
• At flash ROM write
function use
• At parameter
At parameter
initialization request
Always
Operation status at
Error check
error occurrence
The flash ROM write/
parameter initialization
initialization is not executed.
function use
The parameter
initialization is not
executed.
In strat: Deceleration
At start: The operation
11 - 10
Replace the QH74MH.
Review the sequence program
not to exceed 25 times flash
ROM write and parameter
initialization in system's power
supply ON.
Execute the parameter
initialization after PLC READY
OFF.
Refer to the "QCPU User's
stop
Manual (Hardware Design,
Maintenance and Inspection)".
does not start.
MELSEC-Q
Remedy