Guralp Systems CMG-DCM build <10,000 - Manual (Page 97)

Acquisition Modules and Platinum Firmware Networking Configuration
7.8 Configuring TCP to serial converters
The acquisition module can act as a TCP to serial converter, effectively
transporting data between one (or more) of its serial ports and a TCP
connection. There are two different modes of operation, as detailed below.
Any number of serial ports can be configured as TCP converters, as long as
the TCP port numbers do not clash.
In “Simple server” mode, the acquisition module listens for incoming TCP
connections and, should it receive one that matches its configured rules,
accepts the connection and begins copying data between the serial port and
the TCP connection.
The acquisition module can be configured to only listen on particular
addresses and ports, to only accept connections from certain addresses or
blocks of addresses and to reject connections from certain addresses or blocks
of addresses.
In “Simple client mode”, the acquisition module will connect to an external
TCP server on a particular address and port and then copy data
bidirectionally between the serial port and the network port.
MAN-EAM-0003 97 Issue E - February 2014