sigmadelta

This may help too... but verify the NCU/PCU you have first!! https://support.industry.siemens.com/tf//WW/en/posts/restore-the-archive-of-840d-pl/206856?page=0&pageSize=10

This might get you pointed in the right direction... now I remember I restored from an archive that was stored on the HMI (or PCU?) that was connected to the NCU... but this was a different 840D, and I'm not sure which NCU/PCU you have in your system. http://www.plctalk.net/qanda/showthread.php?t=59436

Upon further reading.... The NCU itself sits inside the box. So we still don't know which NCU you have.

Don't you have a computer attached to the system?  What software is running on it?

Note: I am not a Sinumerik expert, I'm only trying to point you in the right direction. I believe this might be what you want, especially chapter 12.4.2.  Unfortunately, I did this only once about 20 years ago, so I don't remember exactly the steps I did. https://support.industry.siemens.com/cs/document/28518260/nck-plc-drive?dti=0&lc=en-WW

First, in order for anyone to help, we need the part number(s) of what you have, and if there is an NCU version printed on your NCU BOX, to either write it, or even better, take a picture of it.

Here is a link to the cable pinouts for TI 305 PLCs: https://cdn.automationdirect.com/static/specs/directsoftcables.pdf Use D3-DSCBL-1 Also you can use either TISOFT 305 or Directsoft from Automation Direct to program the CPU.

It's easier to find if you go online with Siemens STEP 7 software, or VIPA WinPLC7 software, and look at the diagnostic buffer of the CPU.

I sent you a private message.

Another thing that it might be, is the files are read-only.  Find the Step 7 project folder which is in C:\Program Files\Siemens\Step7\s7proj\ and right-click on it an click Properties... uncheck the Read-Only checkbox, and if it asks, apply the changes to all files and folders.

Try right-clicking your HMI in the TIA Portal Project then Compile -> Software (rebuild all).  Save the project, then download.

Open STEP 7 and go online with the hardware configuration to see which Profibus or Profinet nodes are not communicating.  If you don't have STEP 7 software, you have to look at all your Profibus or Profinet nodes to see if they have an error indication.  BF means "bus fault", which means one or more nodes on network 2 and network 3 are not communicating.  Could be a cabling problem, Ethernet switch problem, or device problem.

Maybe this post might help: https://contrologica.com/how-do-i-upload-from-a-siemens-s5-plc-using-step5/

It should work, as long as you wire the connections correctly.

How are you trying to connect, with the RS-232/TTY cable to the port on the S5 CPU?  Are you using STEP 5 software? What communication settings are you using?