Posted 11 Aug 2014 (edited) Hi, there. I have one question about Scan time pulse in Siemens PLC such as my attached file. Could you explain about the logic at there? Thanks for your help in advance. Edited 11 Aug 2014 by Tom749 Share this post Link to post Share on other sites
Posted 12 Aug 2014 (edited) In the example you posted the Marker "M0.5" will be HIGH (On) for the first scan of OB1 when the PLC goes into run mode. It will be LOW (off) for the rest of the scans. Edited 12 Aug 2014 by Moggie Share this post Link to post Share on other sites