Specifications

App - 24
Functions
(1) The PFWRT instruction completion can be confirmed using the complete devices
((D)+0) and ((D)+1).
(a) Complete device ((D)+0)
This device is turned ON by the END processing of the scan in which the
PFWRT instruction is completed, and turned OFF by the next END
processing.
(b) Complete state display device ((D)+1)
This device is turned ON and OFF according to how the PFWRT instruction is
completed.
• When completed normally : Kept unchanged at OFF.
• When completed abnormally : This device is turned ON by the END
processing of the scan in which the
PFWRT instruction is completed, and
turned OFF by the next END processing.
(Same ON/OFF operation as complete
device).
END processing END processing END processing END processing
OFF
OFF
OFF
ON
ON
ON
1 scan
PFWRT instruction
execution completion
Sequence program
PFWRT instruction
Complete device
Complete state
display device
When
completed
abnormally
When
completed normally
Errors
(1) When a dedicated instruction is completed abnormally, the error complete signal
((D)+1) is turned ON, and the error code is stored in the complete status ((S)+1).
Precautions
(1) Do not turn OFF the power or reset the PLC CPU while parameters, positioning
data and block start data are written to the flash ROM using the PFWRT
instruction.
Doing so causes a parameter error or abnormal positioning operation because the
parameters, positioning data and block start data are not written normally to the
flash ROM.
If this error occurs, restart the operation by the method shown below.
• For the QD75 S/W package, write the parameters, positioning data and block
start data again to the flash ROM.
•
For a sequence program, write the parameters, positioning data and block start
data to the QD75 after initializing the parameters (by executing the PINIT
instruction, etc.).
Then execute the PFWRT instruction again.
(2) Number of writings to the flash ROM is up to 100,000 times.
If writing to the flash ROM more than 100,000 times, the writing to the flash ROM
will become impossible.