Guralp Systems CMG-DM24 - Manual (Page 71)

Operator’s Guide DM-24 Digitiser
Issue G January 2003 69
11. GPS RECEIVER
The GPS2 Receiver Unit comprises an antenna, the GPS receiver electronics, wide
range input isolated dc power supply and output line drivers.
The antenna and all the associated electronics above, are all combined and housed
inside a specially designed enclosure. The enclosure is sealed with ‘O’ rings and
manufactured from a hard rigid resin. It is a stand-alone unit that is powered from the
digitiser it is connected to.
GPS data (position, date/time and status) is output in NMEA format at 4800 baud once
per second. Time synchronisation pulse (100 ms duration) is output at 1 pps. Both
outputs use RS232 (or RS422 option) line drivers allowing use of long cables (up to 100
metres or more).
For further information on time stamping and clock synchronization, see chapter 3
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