Terminals HOWTO


Communications using SSH, minicom, stip, etc.

Using SSH

Before starting an ssh session to another node, ensure that both hosts (“fromNode” and “toNode”) will stay awake by establishing a lease for each one:

lease -establish 1200 fromNode lease -establish 1200 toNode

Establishing the lease on toNode may be difficult if toNode is sleeping frequently. In this case try starting the lease process in the background and then using the bcastc utility to wake up toNode:

lease -establish 1200 toNode & bcastc

The examples above establishes a 1200 sec (20 min) lease on “toNode” and “fromNode”; adjust duration as needed.

Start ssh session from fromNode to toNode using command

ssh ops@toNode

The example above establishes an ssh session to toNode using login account ops; the host name may be given as either a host name or an IP address.

Telemetry Consoles

The console processes managed by the auxTelem script (SURFACE freewave, BIN consoles) differ from the dedicated console ports in a couple of ways: They are active for 30 seconds once every 5 minutes. It may be necessary to wait for up to 5 minutes before the console login becomes available.

Once logged in, the console uses a default 30 sec inactivity timeout unless the TMOUT variable is set. Set TMOUT to a value long enough to allow for necessary operation. Setting TMOUT=0 disables the console inactivity timeout.

THIS MAY HAVE SERIOUS CONSEQUENCES as it potentially leaves the radio powered indefinitely if the console link is broken inadvertently.

In general, it is better set TMOUT to some reasonable value.

Instrument Consoles (SIAM application is running)

conPort utility provides a console to an instrument without explicitly halting the service:

conPort <node> <port>

Use ctrl-x x to exit conPort; it may be necessary to use scanPort to restart the instrument service after using conPort:

scanPort <node> <port>

Alternatively, shutdown the instrument service using the shutdownPort utility and restore power and communication to the instrument using the powerUpPort utility before using one of the terminal emulator programs to establish a console to the instrument. When finished, use scanPort to restart the instrument service:

  • shutdownPort <node> <port>
  • powerUpPort <node> <port>
  • <your terminal session here…>
  • scanPort <node> <port>

Instrument Consoles (SIAM application is not running)

dpaView utility allows the user to enable power and communications prior to using a terminal emulator to establish a console to the instrument. The following commands are used to set current limit, turn on power and communications:

  • dpaView scm <dpa (0-11)> <port (0 or 1)> <currentLimitMilliamps>
  • dpaView power <dpa (0-11)> <port (0 or 1)> <ON|OFF>
  • dpaView comms <dpa (0-11)> <port (0 or 1)> <ON|OFF>

Use the help command in dpaView for full descriptions of all commands dpaView commands give help when issued with no arguments.

tty DPA Channel
ttySX0 0 0
ttySX1 0 1
ttySX2 1 0
ttySX3 1 1
ttySX4 2 0
ttySX5 2 1
ttySX6 3 0
ttySX7 3 1
ttySX8 4 0
ttySX9 4 1
ttySX10 5 0
ttySX11 5 1

Terminal Program Options

stip (a variation of Unix tip) provides a basic serial console

stip –s <baudRate e.g. 9600> <port name e.g. /dev/ttySX2> stip –help provides use message with all options stip has no facility to issue a break exit stip using the character sequence “~.”

stip is not compatible with RS422 instruments and may not be compatible with other terminal emulators and consoles.

minicom is a more fully featured terminal emulator

As root: use minicom –s to configure and save a console session As ops: use minicom <session name> to use a saved session

If starting minicom from within another minicom session, be sure to change the control sequence for the outer session to some thing other than the default (ctrl A) before starting the inner session.

See Also