Issue with S 7 300

[sudhanshushahi16@gmail.com]

Hi

i have a s7 300 cpu used in a machine operation but we have an error SF led (red) is constantly on however nachine runs fine in this condition but sometimes the machine just stops dead and nothing at all works at such times the BF led also turns on. Then we turn the power of of the Plc and then tun the power back on and then BF Led goes away but SF led still remains on But as i said in that condition machine runs just fine 

Please suggest what to check for this issue 

thanks and regards

[BobLfoot]

i am not a Siemens guru, but google found this -- https://support.industry.siemens.com/tf/WW/en/posts/what-is-the-means-of-the-sf-and-bf/220559

 

[Joe E.]

You will need a PC running the appropriate Siemens programming software to go online and do the hardware diagnostics to find the root of the issues. A few years ago, with an S7-300, I would have said Step 7 for Simatic Manager is what you need, but it could also have used Step 7 for TIA Portal.

Do you have a copy of the program? If so, that will tell you which software family to use. If you don't have the software, you will need to get it or someone who does have it to stop by your facility to take a look.