Reset/Erase V700 Program from Factory Boot

[Adreasler]

The situation is as follows.  (It's a funny story from the outside.)

I was trying to get a V700 HMI/PLC to communicate with another device through TCP commands, when I realized that both machines have RS-232 ports.  "That will simplify things," I said, and I put in the function blocks to prep COM1 for the communications.  I also removed the now superfluous rungs that set up the Ethernet.

Little did I realize that COM1 was not Port 1, but the USB port, and I also failed to realize that the "Set PLC name" function block was in the ethernet rung I had deleted.

Now I cannot reach the PLC through the ethernet at all, and I can only communicate with it by USB when the PLC is in the 'Pre-boot" stage (power the PLC up while pressing on the screen, then remove finger and press again to half the "countdown to O/S load.")

In this Pre-boot mode, I can communicate with the PLC, but I cannot download a new ladder logic program to it, and if I let the O/S load, it locks out the USB port so I cannot communicate with it to download a new ladder logic program.

Is there a way to remove the PLC's existing program so I can put a corrected program into the system?

[Flex727]

Did you try pulling the battery?

[Adreasler]

Yes, I thought of that as my post was awaiting moderator review.

Unfortunately for me, the V700 stores a backup of the program in FLASH memory, so it automatically loads the program from there into RAM if the battery fails.

It's odd, all the help files state that the COM1 port is disabled when the PLC is physically hooked up to a PC, so, in theory, this problem should not be happening.  However, as Yogi Bera said, "In theory, there's no difference between theory and practice; in practice, there is."

 

[Flex727]

1 hour ago, Adreasler said:

the V700 stores a backup of the program in FLASH memory, so it automatically loads the program from there into RAM if the battery fails.

Only if you "Download All & Burn". There's no reason to waste time with that process until the software is final.

[sgull]

If you have the com settings being set by a power up bit on the program, it may be possible to use INFO mode to change the settings when the unit is running.

[Ausman]

sgull's tip +1.

Or if all else failes, use info mode to completely erase the PLC if you have your program resident on your computer, which you should if you've got this far! 

But......don't forget this will completely  erase the plc, meaning you have to put everything back into it!!

cheers, Aus

[Adreasler]

Ah, info mode can wipe the PLC FLASH memory?

Thank you, this is just the info I need.

Also, the popup text bubbles that show up on the download menu make it somewhat unclear about the purpose of burning to FLASH.  Those cues were leading me to think I needed to burn to FLASH to keep the program after a power cycle. Appearantly I was misreading those cues.

[Flex727]

20 minutes ago, Adreasler said:

I needed to burn to FLASH to keep the program after a power cycle

True when there is no battery, or a dead battery.