/dev/com device names for communication ports	Device
	SYNOPSIS DESCRIPTION Supported ioctl() Requests PORTING ISSUES AVAILABILITY SEE ALSO

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SYNOPSIS

/dev/com/n

/dev/com/nM

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DESCRIPTION

The NuTCRACKER Platform recognizes two forms of device names for communication ports:

• The first form in the SYNOPSIS section corresponds to the Windows device COMn. This device assumes a hard-wired serial connection, and ignores the carrier-detect serial line.
• The second form in the SYNOPSIS section is the modem-control version of the Windows device COMn (hence the trailing M). An attempt to open this device blocks until the carrier-detect line becomes active, unless the port is explicitly opened in non-blocking mode.

By default, the NuTCRACKER Platform supports 12 com ports. You can increase this limit by using _NutConf() to change _NC_SET_MAX_COM_PORTS. This must be done before the first com port is opened in the process.

Supported ioctl() Requests

TCGETS, TCSETS, TCSETSF, TCSETSW  

These ioctl() requests are used to get and set termios parameters, and are documented under sstruct termios. The argument to the ioctl() request is a pointer to a termios structure.

TCFLSH  

This ioctl() request is used to flush pending input and output, and is documented under struct termios.

TCSBRK  

This ioctl() request is used to send a break, and is documented under struct termios.

TCXONC  

This ioctl() request is used for flow control, and is documented under struct termios.

TCGETX, TCSETX, TCSETXF, TCSETXW  

These ioctl() requests are used to get and set termiox parameters, and are documented under struct termiox. The argument to the ioctl() request is a pointer to a termiox structure.

FIOGETOWN  

This ioctl() request is equivalent to fcntl(fildes, F_GETOWN).

FIOSETOWN  

This ioctl() request is equivalent to fcntl(fildes, F_SETOWN, arg), respectively. The argument to the ioctl() request is a process ID or process group ID, as described for F_SETOWN under fcntl().

FIOASYNC  

This ioctl() request is equivalent to using the fcntl() command F_SETFL to set or clear the O_ASYNC flag. The argument to the ioctl() request is a variable of type unsigned long. If this variable is non-zero, the O_ASYNC flag is set, otherwise it is cleared.

FIONBIO  

This ioctl() request is equivalent to using the fcntl() command F_SETFL to set or clear the O_NONBLOCK flag. The argument to the ioctl() request is a variable of type unsigned long. If this variable is non-zero, the O_NONBLOCK flag is set, otherwise it is cleared.

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PORTING ISSUES

Refer to The Communication Port Interface in the PTC MKS Toolkit UNIX to Windows Porting Guide for a detailed discussion of working with communication port devices.

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AVAILABILITY

PTC MKS Toolkit for Professional Developers
PTC MKS Toolkit for Professional Developers 64-Bit Edition
PTC MKS Toolkit for Enterprise Developers
PTC MKS Toolkit for Enterprise Developers 64-Bit Edition

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SEE ALSO

Functions:

fcntl(), open()

Miscellaneous:

/dev/console, struct termios, struct termiox

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PTC MKS Toolkit 10.5 Documentation Build 40.