7 - 9 
MELSEC-Q
7   MEMORY CONFIGURATION AND DATA PROCESS 
 
(5)   Flash ROM write (   ) 
The following transmission process is carried out by setting "1" in "
Cd.1
 Flash 
ROM write request" (buffer memory [1900]). 
 
1)  The "parameters", "positioning data (No. 1 to 600)" and "block start data (No. 
7000 to 7004)" in the buffer memory area are transmitted to the flash ROM. 
The writing to the flash ROM may also be carried out using a dedicated 
instruction "ZP.PFWRT". (Refer to CHAPTER 14 "DEDICATED 
INSTRUCTIONS" for details.) 
 
(6)   Flash ROM request (writing) ( ) 
The following transmission processes are carried out with the [flash ROM 
request] (write) from the peripheral device. 
 
1)  The "parameters", "positioning data (No. 1 to 600)" and "block start data (No. 
7000 to 7004)" in the buffer memory area are transmitted to the flash ROM. 
 
Note)  This transmission process is the same as (5) above. 
 
IMPORTANT 
 
(1) Do not turn the power OFF or reset the CPU module while writing to the flash 
ROM.  If the power is turned OFF or the CPU module is reset to forcibly end the 
process, the data backed up in the flash ROM will be lost. 
(2) Do not write the data to the buffer memory before writing to the flash ROM is 
completed. 
(3) The number of writes to the flash ROM with the programmable controller 
program is 25 max. while the power is turned ON. 
Writing to the flash ROM beyond 25 times will cause the error "Flash ROM write 
number error" (error code: 805). 
Refer to Section 15.3 "List of errors" for details.