Panasonic FP Series Programming Manual page 1308

NOTE
This error is also detected if you attempt to execute a rewrite containing a syntax error during
RUN. In this case, nothing will be written to the CPU and operation will continue.
40.9.2 Table of self-Diagnostic errors
Not all errors apply to all PLCs.
E20 - E39
Error Name
code
E20 CPU error
E21 RAM error
E22
E23
E24
E25
E26 User's ROM error
E27 Intelligent unit
installation error
E28 System register
error
E29 Configuration
parameter error
E30 Interrupt error 0
Operation Description and steps to take
status
Stops Probably a hardware abnormality.
Please contact your dealer.
Stops Probably an abnormality in the internal RAM.
Please contact your dealer.
Stops FP2, FP2SH, FP3, FP10SH:
ROM is not installed.
There may be a problem with the installed ROM.
 ROM contents are damaged
 Program size stored on the ROM is larger than the
capacity of the ROM
Check the contents of the ROM
FP-X:
If the master memory cassette is mounted, the master memor
cassette may be damaged. Remove the master memory, and
check whether the ERROR turns off.
If the ERROR turned off, rewrite the master memory as its
contents are damaged, and use it again.
If the ERROR does not turn off, please contact your dealer.
FP0, FP-e, FP, FP1 C14, C16:
Probably an abnormality in the built-in ROM.
Please contact your dealer.
All FP-Ms and FP1 C24, C40, C56, and C72:
Probably an abnormality in the memory unit or master memory
unit.
Program the memory unit or master memory unit again and try
to operate. If the same error is detected, try to operate with
another memory unit or master memory unit.
Stops Intelligent units installed exceed the limitations (i.e. 4 or more
link units).
Turn off the power and re-configure intelligent units referring to
the hardware manual.
Stops Probably an abnormality in the system register.
Check the system register setting or initialize the system
registers.
Stops A parameter error was detected in the MEWNET-W2
configuration area. Set a correct parameter.
Stops Probably a hardware abnormality.
Please contact your dealer.
Appendix Programming Information
1307