Modification & Review of Existing Siemens PLC Program (TIA Portal V20)

I already have a complete running PLC program developed in Siemens TIA Portal V20 for:

PLC: Siemens S7-1200 (CPU 1212C)
HMI: Siemens HMI (compatible with TIA Portal V20 project)

The machine is already operational. I now need specific modifications and corrections in the existing logic.

Scope of Work
1.Open and fully review the existing PLC and HMI project.
2.Carefully check the list of required changes that I have mentioned inside the project files.
3.Implement the required logic changes properly.
4.Ensure there are no conflicts with existing blocks, functions, or interlocks.
5.Verify that all modes (Auto / Manual / Safety logic) behave correctly after modification.
6.Provide the updated project file with clean structure and comments where required.
7. Install the program remotely on PLC and HMI


Important – Read Before Quoting

Do NOT quote based only on this description.

You must:
- Open the actual program file.
- Review all PLC blocks and HMI screens.
- Carefully check the document where changes are mentioned.
- Understand the current logic completely.
- Then quote accordingly.

Only serious freelancers who properly review the files before quoting should apply.

Required Experience
- Strong experience in Siemens TIA Portal V20
- Experience with S7-1200 PLC programming
- Experience handling existing industrial programs (not just new development)
- Good understanding of structured logic, interlocks, temperature control, and automation troubleshooting

Please mention your past similar Siemens projects while applying.