Bjorklund, Eric A wrote:
For the first time in our experience, we have a serial device (Kepco power supply) that insists on sending XOFF/XON sequences. We are using streamDevice and a Greenspring Octal IP module to talk to it. StreamDevice and Asyn appear to have no problems with the XOFF/XON characters, however the tyGSOctalStartup routine in tyGSOctal.c puts out a continuous stream of
"tyITX ERROR, sr=0c" errors. The cause of these errors turns out to be
that the tyITx() routine (a vxWorks function) returns ERROR if it is called to start a transmission and the transmitter is XOFF'd.
This causes the tyGSOctalStartup routine to log an error -- perhaps because it thinks someone is trying to send a zero-length buffer (no characters left to transmit is the other reason tyITx() will return ERROR).
The easiest way to fix the problem was just to remove the error message (see attached patch file -- which only comments out the offending code in case that turns out to be a bad idea). As far as we can tell, there are no ill effects from this. We seem to be talking to the power supply just fine.
Anybody see a reason why we should leave the error report in tyGSOctalStartup() ?
Thanks,
-Eric Bj
Eric,
XON/XOFF should be resolved on a lower level than StreamDevice and even
asyn. In asyn versions >= 4.17 you can control XOFF/XON behavior on the
OS driver level:
asynSetOption ("port", 0, "ixon", "Y")
Now, the device should not forward XON to asyn/StreamDevice but instead
block the write function until the device is free again (I hope).
Dirk
- Replies:
- Re: XOFF Problem with tyGSOctal Eric Norum
- Re: XOFF Problem with tyGSOctal Bjorklund, Eric A
- References:
- XOFF Problem with tyGSOctal Bjorklund, Eric A
- Navigate by Date:
- Prev:
Re: EPICS and MEDM on ubuntu Dirk Zimoch
- Next:
epics.nsls2.bnl.gov down Michael Davidsaver
- Index:
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
<2012>
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
- Navigate by Thread:
- Prev:
XOFF Problem with tyGSOctal Bjorklund, Eric A
- Next:
Re: XOFF Problem with tyGSOctal Eric Norum
- Index:
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
<2012>
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
|