Posted 19 Oct 2017 Hi all, I am writing a S7 program that contains a couple of SR flip flops. When I try simulating by saving, downloading, monitoring and putting into RUN-P mode even before I turn on any input, the flip flop looks active. Any ideas as to why this is happening? Thanks for reading Share this post Link to post Share on other sites
Posted 21 Oct 2017 One reason can be the use of the same address more than once or using a byte or word. But without more details it is impossible to help, a screen shot would be useful Share this post Link to post Share on other sites
Posted 21 Oct 2017 Thanks for your reply. I did also consider your point and checked the addresses and they had no relation to the others. This happens when I haven't activated any input at all. Just putting the simulator in RUN-P causes this The only way i have got around it is kept changing the address until it stops behaving like that. It may also be a software issue. Here is a screen shot of one I'm currently having problems with. I appreciate your response. Share this post Link to post Share on other sites
Posted 21 Oct 2017 Make sure MB0 is not used by the "clock" memory. In the PLCSIM window show the status of MB0 1 person likes this Share this post Link to post Share on other sites
Posted 21 Oct 2017 You are a star. I have now added the Memory BIT and when I did MB0.7 was ticked. I don't know why because I hadn't used that address previously. I have now unticked it as seen here. Thanks a lot Boss. Share this post Link to post Share on other sites
Posted 21 Oct 2017 (edited) I just didn't understand why it was ticked when I opened the MB when I hadn't used MB0.7 anywhere in the program. Edited 21 Oct 2017 by Rflower Needed to add more. Share this post Link to post Share on other sites
Posted 21 Oct 2017 3 hours ago, Moggie said: Make sure MB0 is not used by the "clock" memory. In the PLCSIM window show the status of MB0 Thanks very much Sir. Share this post Link to post Share on other sites