Mitsubishi Electric MELSEC-LD77MS2 User Manual page 879

[Precautions]
(1) Do not turn ON the power and reset the PLC CPU while parameters, positioning
data and block start data are written to the flash ROM using the ZP.PFWRT
instruction.
A parameter error will occur or normal positioning start will become impossible
because the parameters, positioning data and block start data are not written
normally to the flash ROM.
If this occurs, restart the operation by the method shown below.
• For GX Works2, 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 Simple Motion module after initializing the parameters (ZP.PINIT
instruction execution and others).
Then execute the ZP.PFWRT instruction again.
(2) Writing to the flash ROM is up to 100,000 times.
If writing to the flash ROM exceeds 100,000 times, the writing to the flash ROM will
become impossible.
(3) After the power ON and PLC CPU reset operation, writing to the flash ROM using
a sequence program is limited to up to 25 times. (Not limited to up to 25 times
when writing to the flash ROM is carried out by GX Works2.)
If the 26th or more writing is requested after the power ON/PLC CPU reset
operation, the error "Flash ROM write number error" (error code: 805) will occur,
and the writing will be disabled. If a flash ROM write error occurs by one writing to
the flash ROM, check and correct the flash ROM writing program. Then reset the
error or turn ON the power and reset the PLC CPU again.
(4) The ZP.PFWRT instruction can only be executed when the READY signal [X0] is
turned OFF.
When the READY signal [X0] is turned ON, the ZP.PFWRT instruction cannot be
executed.
Before executing the ZP.PFWRT instruction, turn OFF the PLC READY signal [Y0]
and then turn OFF the READY signal [X0].
(5) When the PLC READY signal [Y0] is turned ON, the error "SSCNET
communication error" (error code: 1205) occurs, "Rotation direction
selection/travel direction selection (PA14)" is changed by sequence program or the
GX Works2 after the servo parameter is transmitted to servo amplifier (LED of the
servo amplifier is indicated "b_", "C_", or "d_").
When "Rotation direction selection/travel direction selection (PA14)" is changed,
transmit the servo parameter to servo amplifier.
15- 13
Chapter 15 Dedicated Instructions