Problem opening/recognizing/using serial port

[jschna1]

So I need to communicate with a serial port using tcl/tk 8.3 but am having a problem: when I try to send data down it, nothing happens. Also, when I try to use fconfigure to set the mode of the serial connection, I get an error that -mode is not a valid argument, as if the program does not recognize it as a serial port. I am using a machine that runs on Red Hat Linux.

This is the code I'm using:

-------------------------------
set port [open /dev/ttyS4 w+]
#I also tried options w and r+ with no better results

fconfigure $port -mode "9600,n,8,1"
#didn't work so I remove it to try writing to the port as is...

puts $port "pos=1\n" #output command to port
-------------------------------

That command should set the device in position one, but the device does not respond at all. Also, in this way when I try to read from the port:

set myData [read $port 1] ## Just read 1 char.

The program just freezes. Is there anything I'm doing wrong?

 

[Bong]

take a look here:

http://wiki.tcl.tk/447

_________________
Bob Rashkin

 

[jschna1]

The difference in theirs is they use RDWR instead of the w+/r+/etc. I tried it to make sure I hadn't before and alas, the same problems. Doesn't send data and freezes when trying to read it.

 

[Bong]

Are you sure the problem is in Tcl? That is, is the port actually active?

_________________
Bob Rashkin

 

[jschna1]

Yes the port is active; using minicom I can communicate with it just fine.

 

[Bong]

I'm afraid I can't really help. I've done a little serial port comm but only on Windows/DOS. There may be a problem with the LINUX Tcl, but I don't know what it might be. That is, I can't see that you're doing anything wrong. You might try posing your question on the ActiveState listserv:

ActiveTcl@listserv.ActiveState.com

_________________
Bob Rashkin