Meinberg GPS163TDHS, Руководство по эксплуатации

Страница: 10 / 34

10
Asynchronous serial ports
Two asynchronous serial interfaces (RS-232) called COM0 and COM1 are available
to the user. In the default mode of operation, the serial outputs are disabled until the
receiver has synchronized after power-up. However, the system can be configured to
enable those outputs immediately after power-up. Transmission speeds, framings
and the kind of the time string can be configured separately. The serial ports are
sending a time string either once per second, once per minute or on request with
ASCII ´?´ only. The format of the output strings is ASCII, see the technical specifica-
tions for details. The corresponding parameters can be set up by GPSMON32 using
serial port COM0.
As an option the serial port COM1 is available as a RS485 interface.
IRIG-outputs
Introduction
The transmission of coded timing signals began to take on widespread importance
in the early 1950´s. Especially the US missile and space programs were the forces
behind the development of these time codes, which were used for the correlation of
data. The definition of time code formats was completely arbitrary and left to the
individual ideas of each design engineer. Hundreds of different time codes were
formed, some of which were standardized by the "Inter Range Instrumantation
Group" (IRIG) in the early 60´s. Detailed information about IRIG and other time
codes can be found in the "Handbook of Time Code Formats", by Datum Inc., 1363
South State College Boulevard, Anaheim, California 92806-5790.
Except these time codes other formats, like NASA36, XR3 or 2137, are still in use.
The module GPS163TDHS however generates IRIG-B or AFNOR NFS-500 only.
The selection of the generated timecode is done by the software GPSMON32.