Jump to content


  • Content Count

  • Joined

  • Last visited

Community Reputation

0 Neutral

About Spyros73

  • Rank

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

  1. I started working on making my own clock, based on the SB of 1/10, but then I thought that this can not work out, because every time I switch off power (and this can easily happen during a rally, as in many cars when engine starter runs, voltage drop is significant, and plc goes off for 1-2 seconds), then the SB are not counting and my clock will stay behind. I could of course automatically syncronize my clock with the RTC every time the plc goes on, but in this case, I will finally transfer the RTC error to my clock. Should I expect any official reply from Unitronics, or I have to send a
  2. This is what I originally tried to do. If you see my demo software, I have used a MB (I think MB6) which comes true every time SI30 changes. And here is where the problem occurs, that even if I syncronize the RTC with a clock, after a while, you can see that the seconds have drift a little bit, so SI30 is not channging anymore syncronized with my clock. And the strange thing is that after a few minutes, it adds half a second, and then they are syncronized again, and so on. The problem is that in those competitions everything has to do with accurancy, and we have achieved such a good one (less
  3. Hi all, thanks for your response. Here some comments from my side. To Flex727: This is exactly the behaviour I have also noticed. Although, the MI21 does not really changes randomly. If you notice, it has a max value e.g 8, and decreases litle by litle till to reach a min value (5 less), and then returns again to its max value. So it look to me like an internal control of the RTC, which every time sees that it has lost 5/10 of a second, it adds 5/10. In fact, in my operational software, we had realy noticed this, just by watching on the clock. We were adjusting it, according to an ex
  4. Oh sorry, just ignore it, I wanted to try if I can force the scantime. ( I can do this in schneider PLC) Anyway, for your info, on my normal software which is much bigger, the scan time is 4 ms
  5. Thank you both, for your reply. Monthly drift of RTC is as you say (~1 sec per day), and this is ok for me, but this is not my problem. I have attached a simple software, where you can see what I mean. I am using 3 counters. MI13 increases by 10 when SB13 is true, MI15 increases by 1 when SB15 is true. MB 19 is their difference, calculated when SB13 is true. MI19 stays constant which sound very logical. I am also using MI17 which increases by 10, every time SI30 (seconds of RTC) change, and then I also calculate the difference between, MI17 and MI15, and save it on M
  6. Hello, I am using SAMBA PLC (4.3 and 7.0 as well) for historic car rallies, in order to calculate ideal distance based on time and a given average speed. I have noticed that the RTC has a strange behaviour. I syncronize my PLC RTC with an accurate digital clock, and after a few minutes, I can notice already, a small difference (e.g. 3/10 of a second). But after a while, the two clocks are syncronized again. I tried also the following. I used the SB 15, which comes true 10 times per sec, and I increase a ML15 every time SB 15 is true. In parallel, I created a bit (MB6) which come
  • Create New...