Again S7 300

HI

I am having CPU 312C, During downloading the program, PC adaptor damaged message is comming. I have one MPI serial cable as well as USB MPI adaptor. I tried to 'Display accessible node' there also I could not connect to PLC. I checked its communication setting all are OK. What could be the problem. If in case wrong hardware configuration is downloaded, how to delete it? any soultion? Please help me out

If its a new PLC you could try a Memory Reset (hold down the MRES switch against the spring until the amber light stays constant - normally after 2 slow flashes, then release and hold down again and the amber light will flash quickly - job done).

If you don't want to reset it, check your PG/PC Interface settings. Try changing the local address of your computer to something out of the way (like 20) and try that.

Also try rebooting the computer and trying to connect straight away just incase something is hogging the com port..

Can you communicate with other PLC's?

Thanks

But I think MERS resets only PLC memory includs Blocks and Data, not Hardware configuration.

Increasing the Local PG add not useful

Please go through snaps

ggchavhan said:

Please go through snaps

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This is last resort. Whisky, cognac, vodka, gin and rum can also be used for this purpose. Has helped me out a few times.

If you're using the serial adapter make sure the 19200 setting that you showed is also what's selected on the switch on the adapter (some of the newer ones let you select 19.2 or 38.4). I've seen that switch get a little sticky (looks switched to one side but isn't quite there) so may be switch it one way then the other.

If you use USB adapter, make sure to select USB instead of COM port and make the baud rate 187.5.

But same adaptor is ok with other PLC for same baudrate.
I want to know how to delete the hardware configuration from CPU bcaus MERS is not useful.

You need to erase the MMC card to delete the hardware configuration. There are two ways, one is to fit into an external prommer and delete from SIMATIC manager. The other one can is to place this MMC into a different type of CPU.
The STOP Led will blink asking for a reset. You have to hold the MR key down for ten secs or so till the amber LED stop blinking. Then release the MR key and bring it down once again quickly. This will erase the MMC card.