Guralp Systems CMG-DCM build <10,000 - Manual (Page 191)

Acquisition Modules and Platinum Firmware Transmitting Data
Heartbeat debug messages: If this check-box is ticked, debugging messages
are generated for every heartbeat packet sent, received or expected but missed.
Debugging messages will normally be written to /var/log/messages but a
different file can be specified in Expert mode.
12.3.2 Configurable parameters in Expert mode
Clicking the button will display an additional tab, “Advanced”, with
three extra fieds.
Log file: It may sometimes be desirable, for debugging purposes, to separate
log messages for this sender from the standard system log. The text field can
be populated with a path name which will then be used for dedicated logging.
MAN-EAM-0003 191 Issue E - February 2014