Operating Manual GPS D25 R/G/Y 6
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System Description
Overview
GPS D25 R/G/Y 6 are displays (7-segment LEDs) of 25mm digit height. R or G or Y
responds to the colour of the LEDs: R = red, G = green, Y = yellow. Digit 6 stands for a 6-
digit display.
The brightness
brightnessbrightness
brightness of the LEDs is adjustable by using the BCD turn switch
BCD turn switchBCD turn switch
BCD turn switch located at the front:
0=1, 2, 3, 4, 5, 6, 7=8=9.
After power-on the display will show the revision number (e.g. ‘5.9 TH‘), any built-in
options and the selected operating mode. To select the operating mode
operating modeoperating mode
operating mode use HEX turn switch
HEX turn switchHEX turn switch
HEX turn switch
at the front. Select e.g. mode = 4 to display the time of the GPS receiver.
Mode Description
0...3 reserved
4Time
TimeTime
Time of the GPS receiver = time of the receiver or of the free-running clock
5Date
DateDate
Date of the GPS receiver = date of the receiver or of the free-running clock
6...7 reserved
8 Time/date of the last synchronisation of the receiver
9 Status information of the GPS receiver
A...F reserved
After a change of the mode with the HEX turn switch the display indicates the new mode for
a moment, e.g.: ‘Mode 5‘.
The built-in GPS receiver
The display has a built-in GPS receiver. An active antenna is connected via a 50 Ωcable at
a SMA female connector. Its built-in pre-amplifier is supplied via the same cable. No
passive antenna must be connected, as this normally causes a DC short circuit. The time
received is output via DSUB female connector every second as a serial telegram.
When the unit is powered off, the real time continues counting battery-powered with the
accuracy of the x’tal (see technical data). So when the unit is powered on, a time
information will be available immediately. With the first synchronous reception of the GPS
receiver (under normal conditions of reception this will take 10 minutes approx.) a switch-
over to GPS time is made. This time is transferred to the output connector with an accuracy
of ± 2µs (jitter) approx. for the seconds pulse (± 20µs for the serial telegram). If then a
GPS reception failure occurs, the time will continue counting with an accuracy of 1µs per
second (10-6). The only pre-condition is that the temperature-compensated x’tal has
meanwhile reached its operating temperature.
The switch-over for Daylight Saving Time will be made automatically. The only time
supplied by GPS is the world time UTC (Universal Time Co-ordinated), i.e. the receiver does
not supply any information about the moments of time for the switch-over. Therefore, this
time is defined according to the current valid legal provision regarding the Central
European Time (CET/CEST), i.e. the last Sunday of March resp. October at 1:00 UTC. If
