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#29 Message resynch

open
nobody
defect (8)
5
2012-08-11
2012-08-11
umby
No

I just was experimenting a bit with Mod_RSSim Modbus_RS232 and found that when it receives a wrong message (CRC error or too few characters or function code unknown) it never resynchronizes any more, i.e. does not respond until you cycle close-open the com. This happened because my master requires ReportSlave ID. It is not important to my master to get a correct reply; it is important not to hang-up. Normally in Modbus any message is considered terminated after a time-out of at least 3.5 characters. Is there any provision in Mod_RSSim to solve this problem ?
Thank you.
umby

Discussion

  • Rufus V. Smith
    Rufus V. Smith
    2012-08-23

    I've found that it goes AWOL even without an error. I can repeatedly send the same message, which it will correctly respond to the first time, then a few more (possibly) of times, then stop completely.
    After a while (a bunch of messages) it will have a message:
    OVERFLOW: Restarting interpretation.
    which occasionally helps briefly (a few messages) but then drops out again...