hidden digital outputs?

Hello!

Recently I was at a packaging machine which have a CPU 313C.I uploaded the project and I saw that 2 digital outputs which are used for heating ( Q124.1 and Q 124.2 ) can not be found with cross references.I mention that I'm begginer in use Step 7 and Simatic products.

Can anyone explaine me why?

Thank you!

Hello,

theoretically I'll be check if some PID is located in code to solve that heating system, calling some system blocks. With this can be that signals joined. Another idea what goes in my head is rewiring outputs to another address, maybe usage of some QB124 with syntax. Look to that and give us info.

Update: how you expect that Q124.x signals as heating system? You have some signal table or you also expect due that HW cfg? Simply if you look to that outputs and heating system can be start heat, that outputs must be ON, correct?

Hi,

Sorry because I'm late with the answer.I attached a picture with cross references.

Hi,

I attached a picture with wiring diagram in which one can see the outputs Q124.1 and Q 124.2 are used.For heating dies believe that using PID function.

hi sanshiro,

is it possible that there is an indirect addressing to this Outputs?

do you know where the heating is proceeded in the PLC-program?

Maybe you can share the project, so we can have a look on it.

regards,

hi mopS04,

I attached the program.

Thank you

Are they changing state on the PLC output card?

I don't see them being written as a bit,byte,word, or double.

Is there a communications network?

Perhaps some other PLC is controlling them.

Some functions can directly address, but I don't see anything that jumps out at me.

Hello,

as I asked, did you look if that outputs turned ON in program RUN? If I open your project, there is info about Protool project, so another idea can be change signals from OP via some DB or memory bits. Another simple check is to look to that physical connector in module where some wire must be connected to that output Q124.X. Via that wire (if exists) you can simply find what device is controlled. Check also if you have ProTool project available and give us info.

I do not know what to say about PLC output card.

The only communication is between PLC and HMI ( UniOP eTop-05 ).