Mitsubishi Electric Q172CPU Programming Manual page 546

10 ROM OPERATION FUNCTION
"
(4) Operation at the
Operation at the "Mode operated by ROM" is shown below.
Mode operated by ROM start
Is the registration
code of internal FLASH
ROM normal ?
Read the system setting data, each
parameter for servo control, Motion
parameter, Motion program in the internal
FLASH ROM to the internal SRAM .
Normal operation start
After that, it is same operation at the
RAM operation.
Mode operated by ROM
(Programs and parameters written in the
internal FLASH ROM are abnormal.)
or
(When the additional parameters (for ROM
operation function) are wrote in the internal
FLASH ROM and a version of operating system
software does not correspond to the ROM
NO operation function.)
YES
(Programs and parameters
written in the internal FLASH
ROM are normal.)
10 - 9
"
Motion CPU WDT error [302] occurs, and
"ERROR LED" turns ON.
Wait the restart of Multiple
CPU system.
After that, it cannot be operated because of
stop status.
Retry the operation for "ROM writing"
"Mode operated by ROM" after confirm the
contents for programs and parameters of
internal SRAM.