Guralp Systems CMG-DCM build <10,000 - Manual (Page 163)

Operator's Guide
give you a value for the “Encryption Key” field; Otherwise, enter a
random string into this field and let the person administering the
server know what you have used.
If the GSTM link fails for any reason, it is automatically restarted.
There may be situations where the link cannot be restarted so, to
prevent almost continuous restart attempts and consequent processor
thrashing, a time delay is implemented between a link failure and a
restart attempt. This defaults to thirty seconds but a different value
can be configured if desired by entering it in the “Exit delay” field.
If a configured link carries no traffic for an extended period, the client
will send “watchdog” packets to the server. This serves two functions:
it reassures the client that the link is still usable and it defeats any
“automatic disconnect on idle” mechanisms which may be active on
some links. The time, in seconds, between such watchdog probes can
be configured by entering a value in the “Watchdog interval” field.
If the watchdog packets do not elicit a response from the server, the
link is assumed to have failed and, optionally, an additional service
can be started in response. This will typically be another GSTM client
in order to establish a back-up link. The GSTM client to be started
should be identified here by its service descriptor, which takes the
form gstm­client.n where n is an integer: 0 denotes the first
configured client instance, 1 the second and so on.
When the GSTM link is established or re-established, it is possible to
run an arbitrary command. Any text entered in the “Link established
command” field is passed to the Linux shell for execution, so this can
be a single command or the path to a shell script to execute multiple
commands. Please contact Güralp support if you need assistance with
this feature.
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