Serial Ports on Windows I created this page in case some people may have some questions or answers about [using a serial port] on Windows. I just tried to communicate with com1 on a Windows 2000 machine. For some reason I could not receive any data using the following commands in Wish. ====== % proc rd_chid {chid} { set msg [gets $chid] puts $msg } % set com [open com1: r+] % fconfigure $com -mode 9600,n,8,1 -blocking 0 -translation auto -buffering line % fileevent $com readable [list rd_chid $com] ====== However, I was able to receive data by putting those last 3 lines into its own procedure... ====== % proc rd_chid {chid} { set msg [gets $chid] puts $msg } % proc open_com {} { global com set com [open com1: r+] fconfigure $com -mode 9600,n,8,1 -blocking 0 -translation auto -buffering line fileevent $com readable [list rd_chid $com] } % open_com # lots of data comes streaming :) % close $com ====== jg ---- Tcl 8.4 greatly improved serial port control across platforms. Refer to the updated [fconfigure] documentation for more info. ---- To retrieve details on input/output errors--which are, in general, frequent, when working with serial lines--interrogate set details [fconfigure $serial_handle -lasterror] 8.3.4 introduced this capability. ---- How can I connect to a com port higher than 9? (I am using a terminal server, and its driver creates com ports upto 16 or so.) Would appreciate answer by mail - anner@flexlight-networks.com Thanks 25Aug2003 [PS]: You need to use the 'generic' name (I think it is actually the UNC path) of the com port. Use the file name \\.\com13 to open 'com13:' Mind you, windows wants to see those all those \ chars, so use [[open \\\\.\\com13 r+]]. I have not tested this myself... E_NO_ACCESS_TO_BIG_SERIAL_CARD. But it does work :) ---- The following code will enumerate the serial devices on a windows XP machine - including USB devices. ====== package require registry proc get_serial_ports { } { set serial_base "HKEY_LOCAL_MACHINE\\HARDWARE\\DEVICEMAP\\SERIALCOMM" set values [ registry values $serial_base ] set result {} foreach valueName $values { lappend result [ registry get $serial_base $valueName ] } return $result } ====== ---- Yep, the above works fine on XP. Try " return [lsort -dictionary $result]" to get the list sorted... -regards ---- enumerate serial devices on win2k-win7(Jee Labs version [http://talk.jeelabs.net/topic/208]) ====== # 2010-04-21 improved version, see http://talk.jeelabs.net/topic/208 proc RawListSerialPorts {} { set result {} set ccs {HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet} foreach {type match} { Serenum {^FTDIBUS.*_6001.(\w+)} usbser {^USB\B.*\B(.*)$} } { # ignore registry access errors catch { set enum "$ccs\\Services\\$type\\Enum" set n [registry get $enum Count] for {set i 0} {$i < $n} {incr i} { set desc [registry get $enum $i] if {[regexp $match $desc - serial]} { set p [registry get "$ccs\\Enum\\$desc\\Device Parameters" PortName] # Log . {usb-$serial Port: $p\ Friendly: [registry get "$ccs\\Enum\\$desc" FriendlyName]} lappend result usb-$serial $p } } } } return $result } ====== ---- Note that you most frequently see code something like this: ====== set serial [open "COM1:" "RDWR"] fconfigure $serial -mode 9600,n,8,1 ====== where fconfigure sets the baud rate, etc. of the serial port. <>Device Control|Windows