Panasonic FP Series Programming Manual page 986

Password
Setting
This changes the password specified by the controller, based on the contents specified by the
character constant.
This changes the password specified by the controller to the contents specified by the second
keyword. The first and second keywords are separated by a comma.
Keyword setting for 4-digit hexadecimal password
PASS: Fixed
Password (example: To set the password to "ABCD")
Keyword setting for 8-digit alphanumeric password
Enter for example 'PAS,FP-X v 3'. Spaces at the end of the password are not significant.
PAS: Fixed
Password (example: To set the password to "FP-X v 3")
Precautions during programming
 When this instruction is executed, writing to the internal F-ROM takes
approximately 100ms.
 If the specified password is the same as the password that has already been
written, the password is not written to the F-ROM.
 We recommend using differential execution with this instruction.
 Separate first and second keywords with a comma "," and do not use spaces.
Error flags
No. IEC address
R9007 %MX0.900.7
R9008 %MX0.900.8
In this example the function SYS1 is programmed in ladder diagram (LD).
Example
POU header In the POU header, all input and output variables are declared that are used for programming this
function.
PASS,ABCD
PAS,FP-X v 3
Set If
permanently  any character other than a keyword is
specified
 no comma is between the first and second
keywords
for an instant
 small letters of the alphabet are used to
specify the keyword
 the data specified for the password setting is
any character other than 0 to 9 or A to F, or
the specified data consists of other than four
digits.
System register instructions
985