RE: ASYN Communication through windows serial port (via USB)

[Mark Rivers <rivers@cars.uchicago.edu>]

Josh,

It is possible that the problem is not actually with the baud rate setting, but with some other parameter.  The way that the Windows SetCommConfig function works is that a large structure that defines all of the serial port parameters is passed to SetCommConfig.  It is possible that the default value of some other parameter is set incorrectly for this port, so when you change the baud rate it is actually the value of some other parameter that is causing the error.

What happens if you try to change the data bits, stop bits, parity, etc. first? Do you get the same error for them?

Mark

________________________________________
From: tech-talk-bounces@aps.anl.gov [tech-talk-bounces@aps.anl.gov] on behalf of Josh Stein [stein@aps.anl.gov]
Sent: Friday, March 02, 2012 4:03 PM
To: tech-talk@aps.anl.gov
Subject: ASYN Communication through windows serial port (via USB)

Boy how I hate bringing this stuff up on a Friday...

I have a need to communicate to a serial based instrument off of a
windows laptop. I have the latest ASYN build, which supports COM port
mapping for windows. Like any 'modern' laptop, this machine does not
have any built in serial connections, so I have a USB adapter which maps
COM3 to a serial port. I can talk to the device via a terminal program
on machine.

I execute the following on a softIOC running on the windows box:

drvAsynSerialPortConfigure("L0","COM3",0,0,0,0)
asynSetOption("L0",0,"baud","115200")

setOption failed COM3 error calling GetCommConfig 87


Note the setOption failed error; this is (apparently) preventing me from
setting the baud rate to 115.2K (which, of course, is what the external
device needs). (As an aside, I contacted Mark Rivers and he pointed out
the typo in the error message - it should read: "...error calling
SetCommConfig...")

I know this adapter handles that baud rate, as I can set it via a
terminal program and communicate to my external device.

Any ideas?