upload program

[Guest Stef_pen]

im using sysmac cpt to program a short ladder diagram for c200he, the c200he has an old ladder diagram, how come when i upload the new program into the c200he, then download the program from the c200he, i also get the old program and the new program from the cpu? does uploading the new program to the c200he automatically erases the old program? if not, how do i erase the old program from the c200he cpu?

[Jay Anthony 118]

Are you sure you're not doing an online edit?

[stef168 0]

i was in programming mode when i uploaded the new ladder diagram from the computer to the plc, then i opened a new file , downloaded the ladder diagram from the plc to the computer, what i saw was the new ladder diagram on top of the old one, the new ladder diagram and the plc is working fine. What are the procedures for uploading a ladder diagram from the computer to the plc? Thanks jay

[ECSI 17]

You should see an option to clear program memory before downloading to plc. Make sure the tickbox is checked. Paul

[IO_Rack 178]

I believe this is a bug in CPT. I've experienced the same problem. It seems if you make changes to a program in a PLC by reducing its size, uploading it back into the PLC the last part of the old program remains after the new END statement. One problem this causes is the program will fail a compare. This means you will not be able to do an online edit afterwords. (This used to drive me nuts! :*-( ) I think Paul has the best option here. Clear the memory first.

[stef168 0]

thanks guys, paul , how do i clear the memory? when i go online, and upload the program, there is no window that let me select if i want to clear the memory, will the old program conflict with the new one?

[stef168 0]

and also, i have tried removing the battery from the CPU, to maybe remove the old program, but it still is there when i checked

[ECSI 17]

sorry stef, I didnt notice that you were using CPT. With CX-Programmer, the user has the option to clear program memory before transferring to the PLC. I'm not sure what options are available with CPT. Removing the battery while the PLC is not powered should clear the program. Make sure you leave the battery out long enough. The manual says the program can be lost within 5 minutes, but I'd leave the battery out a little longer just to be sure. Good luck. Paul

[Guest Stef_pen]

thanks paul, ill try removing the battery