ProSoft Technology MVI69E-LDM - Manual (Page 49)

MVI69E-LDM ♦ "C" Programmable Contents
Linux Application Development Module Developer's Manual
ProSoft Technology, Inc. Page 49 of 130
August 21, 2014
4.2.2 Serial Sample
To run the Serial sample:
1 Establish a command window using Telnet or similar terminal software on the PC
through the Ethernet E1 port or Serial P1 port.
2 Login:
user: root
password: password
To execute the sample:
1 Navigate to the default home directory /psft/sample .
2 Type the command ./Serial_Sample ttyS1 test string in order to run the program with
ttyS1 as the output, and "test string" sent to that port.
While reviewing the source code for Serial_Sample , you'll see that the main program:
 registers
sigquit_handler for four signals.
 checks command line and print usage message if required.
 opens the backplane using
open_backplane() . See the detailed description in
backplane_sample .
 reads the serial configuration jumpers and ensures that both serial ports are configured
as RS232.
 opens the serial port using function
open_serial_port() . Examine this function:
o opens the serial device by calling open() .
o reads current serial port attributes using tcgetaddr() .
o configures serial port attributes. The routine uses cfsetispeed() to set the baud rate.
It then uses tcsetattr() to set the remaining attributes.
 initializes the LEDs on the front panel.
 enters a for loop which transmits a test string one character at a time by calling
write()
and sleeping for 500 msec using usleep() .
 closes the serial drive connection using
close() .