Simatic Code Protection or Automatic Deletion

Hi Guys
I am intermediate Simatic Programmer
I am facing payment problems from one client. He is always asking support however They always avoiding to make payment for my invoices
I am sorry to asking but i have to force him to payment for my endeavor
How can i protect my codes
How can i trigger automatic deletion upon time basis for this client.
Thank you from now for your concern
Best Regards

There are several threads here on the site discussing this. The short answer is "don't do it". You should retrieve your code and no longer provide support. Very serious liability issues can happen if you auto delete code on operating machinery. If it is an important customer just take the hit and move on.
See this thread for an example:
http://www.plctalk.net/qanda/showthread.php?t=91772

I agree with jrwb4gbm.

If the code in the PLC is protected with a password, and if you stop giving support, no one can access the PLC and upload your program to make changes.

I think this is the type of protection you should use.

Since they are repeatingly asking for support, why not ask them to pay the due bills, and pay the next visit in advance.

JesperMP said:

Since they are repeatingly asking for support, why not ask them to pay the due bills, and pay the next visit in advance.

Click to expand...

I have some friends in the art world who did something like this. They often did freelance work for a specific customer who had a habit of not paying for work done. They put a clause in the contract charging payday loan type interest rates for unpaid bills, and said that additional work would not be started until unpaid balances were paid.

The customer signed off on the clause without reading it, then didn't pay, as usual. When they called for additional work later, my friends pointed to the clause in the contract. The interest meant that the bill was almost doubled, and the customer said "screw you, we can figure it out on our own". A few months later the customer called back, and said "ok, how much does it cost now, we'll pay whatever". The interest ended up meaning they got paid $6k for a $2k job, and they never had a problem from that point on.

Do NOT change anything in the program, as this ends in liability, make a copy of the program that is in PLC NOW. Put it on a stick and send it to client to keep it in stock (keep it also for yourself.) If invoice is not paid ask them nicely, with interest (I charge them 2% /month overdue, yes it is on the invoice).

Another thing is support: sent them an proposal and tell them payment in advance is needed (same as Siemens does for new clients). Never overcharge, but just normal billingprices.
And remind the guy asking for help, is not the guy that pays you. Probably he has same problems with his boss.