Guralp Systems CMG-DCM build <10,000 - Manual (Page 129)

Acquisition Modules and Platinum Firmware Receiving Data
Note: When configuring units without a dedicated console port,
such as the CMG-DCM, take care not to “lock yourself out” of the
system by, eg, configuring all serial ports for non-terminal functions
before completing network access configuration.
10.1.1 Configurable parameters in simple mode
The configurable parameters for GCF input ports are contained in a single
form in simple mode:
Port Function: Select “GCF in. Inbound GCF data gathering”.
Port speed: Set the appropriate Baud rate from the drop-down menu
Click on the GCF input settings link.
In simple mode, the only option available is to disable BRP rewinding. In
some modes, some digitisers will not allow BRP to rewind to earlier blocks. In
these modes, missed packets will, instead, be sent at a later time. However,
the log-file will accumulate many entries about sending NAKs and giving up.
These may be avoided by telling the receiver that its digitiser is using one of
these modes and that rewinding will not work. The log messages are
harmless, so leave this check-box clear if unsure.
MAN-EAM-0003 129 Issue E - February 2014