kdb066: QNx4.22 Modem and Tinit Examples

Title: QNx4.22 Modem and Tinit Examples
Keywords: QNX4.xx modems tinit
Date: November 29, 1996
KDB: KDB-066
Revision: 0.00
Author: KAM
Distribution: External

How to get QNX4.xx to answer a modem on a serial port and send a login. To do this we use the “modem” command and tinit.

EXAMPLES

tinit -c “modem -b (baud) -L” -t /dev/nt16 &

Or

tinit -t con1 con2 -c “modem -b (baud) -L” -t /dev/nt16 &

To start up two virtual consoles as well as the “modem” program.

NOTES:

  • c :Tinit will start the following command specified by -c on the
    devices specified by -t. (-t) to start program immediately on
    the device.
  • b :The “modem” command to set baud rate.

Under Qnx4 The Nt960 baud settings are:

  • 115200 134
  • 76800 110
  • 64000 75
  • 57600 50
  • L: Use locked baud rate.
  • It was found that the description of the device connected to the MODEM must be after the “modem” command and not before. See examples illustrating the importance of positioning:

tinit -t /dev/nt16 -c “modem -b (baud) -L” & {this won’t work}

tinit -c “modem -b (baud) -L” -t /dev/nt16 & {,but this will work}

  • Use these AT commands to set up the MODEM…AT E1 Q0 V1 X1 &C1 &D2.
  • Other values can be specified for “modem” such as parity,stop and start. See the QNX4 manual under “modem” for great detail.

Description: When someone phones the MODEM, the string “ring” is sent to the computer from the MODEM. The program “modem” will then recognize this as a ring and will tell the MODEM to answer. When the two MODEMs are setup and in contact, “modem” will then die and the port is handed over to tinit who then throws a login on that port.

End of KDB-066

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