Q02(H) Reverting to old program

Hi Guy's,

I am using GXIEC version 7.01 to program a Q02(H) PLC. Last week I left the PLC tested and working. When I returned to the PLC after 3 day the program had reverted to an older version of code. Has any one come across this? If so do you know how to avoid.

Sounds like someone cycled power and the old program was in the eprom/flash memory. Your new program was running from ram.
Just a guess but it has happened to me with siemens - it was my fault for not flashing the program.

rigicon said:

Sounds like someone cycled power and the old program was in the eprom/flash memory. Your new program was running from ram.
Just a guess but it has happened to me with siemens - it was my fault for not flashing the program.

Click to expand...

No, this is not the problem. The CPU only has RAM and no Flash installed.

You say you don't have flash card installed... but are you sure you don't make confusion with internal standard rom boot settings?
Create a new project and upload prog.+parameters from your cpu.
Check exactly where your program is downloaded in cpu.
And check project parameters about booting project

bye
Max