Specifications

App - 25
(3) After the power ON and PLC CPU reset operation, writing to the flash ROM using
a sequence program is limited up to 25 times. (Not limited up to 25 times when
writing to the flash ROM is carried out by a peripheral device.)
If writing to the flash ROM is requested more than 25 times after the power
ON/PLC CPU reset operation, the flash ROM write number error (error code: 805)
will occur, and the writing will be disabled.
If the flash ROM write error occurs even if writing to the flash ROM is requested
only one time, check and correct the writing program.
Then reset the error, or turn ON the power and reset the PLC CPU again.
(4) The PFWRT instruction can be executed when the QD75 READY signal (X0) is
turned OFF.
When the QD75 READY signal is turned ON, the PFWRT instruction cannot be
executed.
Before executing the PFWRT instruction, turn OFF the PLC READY signal (Y0)
and then turn OFF the QD75 READY signal.
Program example
(1) The following is a program used to write the parameters, positioning data and
block start data stored in the buffer memory to the flash ROM when X3D is turned
ON.
No.26 Flash ROM write program
Flash
ROM
write
command
X3D
M26
X0C
M27
Y0
M38
M39
T1
Flash
ROM
write
command
pulse
BUSY
signal
Flash
ROM
write
command
storage
PLC
READY
signal
PLC
READY
signal
OFF
confirm
-ation
Complete
device
Abnormal
complete
device
Flash
ROM
write
command
storage
Complete
device
PLC READY
signal OFF
confirmation
Flash ROM
write
command
storage
Flash ROM
write
command
pulse
Flash ROM write command pulsed
Flash ROM write command hold
Standby of PLC READY signal output to QD7
5
Flash ROM write execution
Flash ROM write command storage OFF
Control data
for PFWRT
instruction