hello everybody.

I want to download program to S7-200 without change initial value.Is it possible?

If  I don't download data blocks , initial values are changed ?

akbar_torkashwand

hello everybody.

I want to download program to S7-200 without change initial value.Is it possible?

If  I don't download data blocks , initial values are changed ?

Values stored in V-memory is untouched when you load only the program block. The same cannot be said for values in the M-memory. What you mean by "initial values" are only a guess for us.

You have not provided the program (observation not critique). It is impossible for anyone to predict what happens when the PLC boots up. Perhaps some values are changed; perhaps not. 

It is best if you can make a status chart and record all the parameter values that are of concern to you. Make a screen grab or copy-paste to a spreadsheet / text file.

Note that the status chart only updates the fields that is displayed on the PC screen. Off the page values are not updated. So you need to make copies of the values page by page.

qwazee

 

akbar_torkashwand

hello everybody.

I want to download program to S7-200 without change initial value.Is it possible?

If  I don't download data blocks , initial values are changed ?

Values stored in V-memory is untouched when you load only the program block. The same cannot be said for values in the M-memory. What you mean by "initial values" are only a guess for us.

You have not provided the program (observation not critique). It is impossible for anyone to predict what happens when the PLC boots up. Perhaps some values are changed; perhaps not. 

It is best if you can make a status chart and record all the parameter values that are of concern to you. Make a screen grab or copy-paste to a spreadsheet / text file.

Note that the status chart only updates the fields that is displayed on the PC screen. Off the page values are not updated. So you need to make copies of the values page by page.

 I want to upload program from PLC and edit program .there are some v-memory that  are adjusted to work  machine  . I don't know about them so I don't want change them. but if I download program, all of them will change . is it possible to edit program online?

akbar_torkashwand

I want to upload program from PLC and edit program .there are some v-memory that  are adjusted to work  machine  . I don't know about them so I don't want change them. but if I download program, all of them will change . is it possible to edit program online?

Yes there was a way to do online changes but there are some rules that had to followed. I cannot remember all the detail so you will have to do your own research. Start with the system manual.

The V-memory should stay in tact, but there is no guarantees on how the program functions. As a stranger it would be easy for me to say that nothing will go wrong. In reality the risk remains your own. The risk increases if you do not study and understand the upload you make. The less risk path is to make the OEM (original equipment manufacturer) part of the solution. 

As they say in finance: the biggest risk has the biggest payout.