Hello everyone. Normally the panel side is my half of the job, but this labeller came in as a bought-in unit and the PLC project has landed on my desk. CPU 1512SP-1 PN, TIA V16.
I was asked to add an alarm bit for a new sensor. FB_Labeller asks for a password when I try to open it and nobody here has one, so I made my change in FC_Main where the FB is called, and now compile stops with an error that points at that call and mentions FB_Labeller. I restarted TIA and compiled again, same thing. One of the older lads says delete the FB and make a new one with the same name, which sounds like a bad idea to me.
What am I actually allowed to do with a protected block? Deleting it and making a new one with the same name still sounds wrong to me, could someone explain what that would actually break?
V16 here as well. Don't delete it, and don't go looking for some tool that opens protected blocks either, whoever suggests it.
Paste the compile error exactly, the whole line. And what did you change in the call in FC_Main? A protected FB can still be called and its inputs and outputs used, that part doesn't need the password.
Error is: "The interface of the called block 'FB_Labeller' does not match the call in 'FC_Main', network 3." Close to that.
I added a new input pin on the call for my sensor, because I assumed the alarm had to live inside the FB. I think that's it, then.
The error is in your call, not in the block. You added a parameter the FB doesn't have, and you can't add one to the FB without the password.
Undo the extra pin on the call and the compile goes through. Put your alarm in your own logic in FC_Main, or a new FC of yours, using whatever the FB already gives you as outputs. If the alarm genuinely has to live inside the FB, that's a change request to the machine builder, and they'll usually do it or hand the password over against a signed form. I've shipped machines with every block protected by default and only handed it over when somebody asked, so ask.