VeriFone MX800 Series - COM Ports on the M 800 Series of Terminals; Com1

DEVICE DRIVERS
COM Ports on the M
x
800 series of Terminals
98 M
X
800 SERIES PROGRAMMERS GUIDE
COM Ports on
the M
x
800 series
of Terminals
There are 4 COM ports on the M
x
800 series of terminals labeled COM1 – COM4
plus an additional USB device serial port, COM5. They are referenced in software
as the following devices:
• COM1 = /dev/ttySAC0
• COM2 = /dev/ttySAC1
• COM3 = /dev/ttyWR0
• COM4 = /dev/ttySAC2
• COM5 = /dev/ttygser
Some ports are optional depending on the specific M
x
800 series of terminals
configuration. All ports can be used as a general RS232 port which can be
configured for different baud rates, character sizes, parity, and stop bits using
either standard Linux calls or the svcSetOpenBlock() call. They can also be
configured to work in character or packet mode, such as the Visa protocol, and
with or without flow control if that port supports it. The baud rates supported on all
ports are: 1200, 2400, 4800, 9600, 19200, 38400, 57600, and 115200. COM5 is a
special USB port that acts as a serial port and baud rate settings do not apply.
Unlike other VeriFone terminals, the serial port devices can be opened for control
by more than one process at a time. To prevent others from using the port at the
same time, use the following ioctl() calls to have exclusive access to the
opened port.
Due to the limitations of the ARM processor, the M
x
800 series of terminals COM
ports do not support the detection of parity errors and BREAK conditions.
It is the responsibility of the application to know which control and status lines are
supported by each COM port, as stated below. Control lines not supported by the
hardware will report the last status set by the application, and unsupported status
lines will report as being asserted.
COM1
COM1, or device /dev/ttySAC0, supports the following hardware lines: RTS,
CTS, and DCD.
The RTS/CTS flow control uses the Samsung S3C2410 UART’s Auto Flow
Control. In this mode, the UART will control the RTS line automatically, and cannot
be set by the application.
TIOCEXCL Put the ttySACx into exclusive mode, where no further open()
operations are permitted. They will fail with EBUSY, except for
root.
TIOCNXCL Disable exclusive mode.