Olivier

PLC program uploading automation

6 posts in this topic

Hi,

In conception phase we currently use GXWorks to upload programs to PLC (L-Series).

In production mode, for different security reasons we would like to automate this transfer so that the operator does not access directly to the program. Do you know any tool allowing this by using command lines and not GXWorks UI ? (GXWorks does not seem to be "command line" friendly :shrug:

As a POC I  have automated the GXWorks UI in C#  (by simulating menu or buttons clicks) but I don't find it reliable (what if an unexpected popup "pops" ? ).

PS : I am a totally noob in this PLC world so maybe I missed stg in the docs ... 

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Why don't you password potect the program. ?

You could also transfer the program via FTP.

OR put the program on an SD card at power up it will load from the SD card.

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Hello,

First of all thank you for your suggestions !

Why don't I password protect the program ? Well ... because I thought to protect the PLC content but I did not think of protecting the source program at all. Thx ! After some tries it already helps me a lot. :-2

But that won't solve all my problems because I meet a vicious circle because actually I want my operator to be allowed to write on the PLC but not to read from it :

  1. The operator gets the source program file from a file server
  2. The operator open the source program with GX (and thanks to your suggestion he can't read it : OK)
  3. The operator then write the program to PLC.
  4. The operator set the read/write PLC password(s) into the PLC (I didn't try yet but I don't think we can define a read password on the PLC before having downloading any program on it)
  5. The main point : how to prevent this operator from reading from the PLC and downloading it into a new GX file ?

I thought of SD cards but I have been told the transfer from SD card was really slower than USB and we will have several programs with several operators. So I am quite sure that on the second production day we will discover some PLC with the wrong program on it :doh:

About FTP : When the Ethernet connection is used between PC and PLC we really can use FTP to upload/download the program ? I thought it was only a feature to transfer data but not the program. I will have a look on this ...

By the way for FTP and SD Card what do you transfer/copy on it exactly ? Is it a .gxw file or is there any result file being generated from GX Works to get ? When I use USB I don't see any output file so I suppose the program content is directly streamed through the USB port.

 

To sum up having a tool using some configuration files to download program into PLC while setting a reading password on it after writing would have helped me a lot :nana:

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6 minutes ago, Olivier said:
  1. The main point : how to prevent this operator from reading from the PLC and downloading it into a new GX file ?

If you download it with the source file. Then when you read the source it would still contain the security. However he could read the source bit then it would be without the statements etc.

10 minutes ago, Olivier said:

By the way for FTP and SD Card what do you transfer/copy on it exactly ? Is it a .gxw file or is there any result file being generated from GX Works to get ? When I use USB I don't see any output file so I suppose the program content is directly streamed through the USB port.

Instead of writing the program to the PLC you write is to an SD card or HD location.

>>Tools >> IC memory card ==> Write .......

 

 

 

 

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So after a few days to investigate and fight with various issues.

  • The IC Memory Card features wrote me some "qpg/qpa/dat password protected files" on my hard drive. -> Checked
  • Link my PC to PLC through Ethernet (after many unsuccessful tries due to a defectuous wire) -> Checked
  • Connect to the PLC via FTP (after many unsuccessful tries due to Windows Defender Firewall) -> Checked
  • Write files on PLC via FTP -> Checked
  • Develop a C# program to do the job (just to keep a trace of it : to make FtpWebRequest work it must be configured with KeepAlive = false and UsePassive = false) -> Checked

Conclusion :

  • Thanks to your help it seems I have succeeded in having a reliable tool to transfer programs to PLC :notworthy:
  • I found just one limit (hoping I won t meet it) : program and parameters files can only be written on Device Memory when using FTP and not on the ROM (it is a MELSEC documented rule) -> I cross fingers for our programs to be small enough :-2

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Congrats sound like a job well done 

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