Transfer siemens HMI program to PC

[CQ21]

Hi all

I am trying to make some changes to a siemens touch panel (MP277 10") numeric display item which is displaying incorrectly but I need to know where the tag is in the PLC. I did not set up this hmi nor program the plc so what I know about the setup is limited.

I have what I believe is the original PLC program but it does not have a WINCC flex hmi station so I can't make changes to the hmi from step 7. I am used to having all the components in one project so this is new to me. My question is...is it possible to program a siemens hmi separately? Can I just export the hmi project currently running straight from the panel itself and find the tag that way? Any advice would be much appreciated!

Thanks!

 

[JesperMP]

Yes, a Siemens MP277 HMI can be programmed separately, i.e. not integrated with the STEP7 Project of the PLC.
The variables will be defined by the absolute addresses, not symbolically.
In TIA you can connect a HMI with the PLC in a separate project by means of the "Proxy PLC". Dont think this is possible with WinCC Flexible.

Unfortunately you cannot load the WinCC Flexible source code, unless it was stored on the panel by the original programmer.

It is possible that there is some remains from a prevously integrated WinCC Flexible program.
Try to look into this folder:
C:\Program Files (x86)\Siemens\Step7\S7Proj\[projectname]\HmiEs\
if there is a folder named PROJECT_1 or similar, see if there is any .hmi file there.

If you cannot get any source file, then to reverse engineer an HMI program based on the PLC program is possible, expecially if the HMI program is relatively small and simple.
But it takes good knowledge of STEP7 and WinCC Flexible as well as perseverance.