S7-300 Variable Record

Hello Aziz;

It always has been difficult to use the S7-300 for data logging, without external connections.

Specially if you would like to timestamp your values the internal datablocks become saturated very quickly. You woiuld need to calculate the number of variables you wan t ot log, the size of ech sample, the frequency of the sampling and the length of time you would like to log, before you determine the minimum size of a DB in the PLC ,memory. and you would need an application to read out htese data to make spaceavailable in the pLC memory at regular time.

You could connect your PLC to an external data log holding space; for example an HMI with logging properties, or to a SQL database on a PC, using OPC or TCP/IP.

Look at this link for an example: https://www.youtube.com/watch?v=bltsB07DOT0

But unless your project hardware is unchangeable, I would examine the use of a S7-1200 CPU, relatively cheap, with datalogging capacity..It would be much simpler:

Sample program: S7-1200 and Datalog

https://support.industry.siemens.com/tf/ww/en/posts/57715/

Hope this helps,

Daniel Chartier

Egyptian Aziz

Is there any way to record some variables in S7-300 ?

We've a problem in our factory, and we need to record two variables.

I can monitor them from variable table, but is there any way for recording the monitoring ?

Or better to use video recorder ...

 Hello, 

As Daniel adviced here. I want to ask you what is the sampling time you need for recording these variables? 

You can think about connecting HMI or a PC with Wincc Flex or TIA. and create trend view for these variables.

And if you want to log the variables in a table view, you can create log for these tags. 

Hope this helps. 

Hello Aziz;

Does the line stop affect the PLC? Is there a SF or BF LED active on the CPU when the fault occurs, or any red LED on any IO module?

If so, your CPU has a built-in logging system for diagnostic events, the diagnostic buffer, that can help youi determine the origin of your problems. 

Tell us if this is the case, we could ell you how to interpret messages from the buffer.

Hope this helps,

Daniel Chartier