Downloading to the PLC

Hi, recently i have been downloading a program to a PLC on site at my work. The program was written several months before. So when i connected the PLC stopped, the plc communicating (before this said there was changes in the current program compared to the original). I was told that as the PLC has been running for a few months some of the variables in the plc will have changed and so downloading the original program to the plc would not account for these issues. To get the original the program to work, would you have to reset the plc then download a fresh or it there an other way get around this. Or as the plc program is already downloaded can you read this program directly from the plc??

Stu

Might help to clue us in as to what brand/model PLC you are working with...



-Eric

a few more facts please. first what brand make model and software.
in short it is best practice to first upload and save a copy of the existing program before downloading to your plc.

Hi Guys, thanks for the replies. I purposely made the question as general as possible. Im using a beckhoffs twincat, but i do know with siemens S7 you can upload from your plc without the original program. What ive been told with beckhoff you need the original program to upload. But if changes have happened to the Program currently on this plc. How do you upload then??

"Trick questions" are NOT cursory to proper answers when it comes to automation projects.
Please state "Facts" and "Real" data to get "GOOD" information about systems that you are inquiring about.

RussB said:

"Trick questions" are NOT cursory to proper answers when it comes to automation projects.
Please state "Facts" and "Real" data to get "GOOD" information about systems that you are inquiring about.

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Solved, thanks to another forum

Was it this one ?

Ken Roach said:

Was it this one ?

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plcstu1980 said:

I purposely made the question as general as possible.

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Why ?

plcstu1980 said:

Im using a beckhoffs twincat, but i do know with siemens S7...

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Why do you think that what you can do with Siemens you should be able to do with a Beckhoff ?

plcstu1980 said:

What ive been told with beckhoff you need the original program to upload.

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Did you ask Beckhoff that question ?

plcstu1980 said:

But if changes have happened to the Program currently on this plc. How do you upload then??

Click to expand...

Did you ask Beckhoff that question ?

Ken Roach said:

Was it this one ?

Click to expand...

Aww you poor *******