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Problem with RS422 — Parallax Forums

Problem with RS422

HjehanHjehan Posts: 5
edited 2009-10-09 16:06 in Propeller 1
We have a STAMP bs2 application that's been running for several years without problems on a 'older' PC IBM300PL.··We communicate with·the PC via port 1 RS232 to a·RS422 converter.· Then one day we change to a faster PC (Dell 755) & all at once we have communication errors.· Specifically, our message consists of 21 characters, the last is a checksum char.· Our problem is that we're now getting frequent check-sum errors.

Any thoughts?

Here's our command to pull in the message:
SERIN PCdataInPin,NormBaud9600,PCReplyTimeout,DecodePCmsg,[noparse][[/noparse]STR PCmsg\21]

One piece of info: We've found that the problem is much less severe if we go into Device Manager and uncheck the FIFO box in the Advanced properties tab for the PC's RS232 port.

Help!

Comments

  • JonnyMacJonnyMac Posts: 9,202
    edited 2009-10-09 15:20
    You've posted in the wrong forum. This forum is for the Propeller Chip, not the BASIC Stamp.
  • HjehanHjehan Posts: 5
    edited 2009-10-09 15:40
    Oops.· Sorry - thanks.
  • BigFootBigFoot Posts: 259
    edited 2009-10-09 16:06
    Older PC's had +-12 volt RS232 signals but the newer PC's use +-5 or 6 volt signals. Maybe your RS442 converter does not like the lower voltage signals.

    Russ
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