Meinberg GPS169PCI, Руководство по эксплуатации

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the new almanac is complete and the system switches to Warm Boot mode scanning
for other satellites.
In the default mode of operation, neither pulse outputs nor the serial ports will be
enabled after power-up until synchronization has been achieved. However, it is possible
to configure some or all of those outputs to be enabled immediately after power-up. If the
system starts up in a new environment (e. g. receiver position has changed or new power
supply) it can take some minutes until the TCXO´s output frequency has been adjusted.
Up to that time accuracy of frequency drops to 10
-8
reducing the accuracy of pulses to
±2µs.
Firmware updates
Whenever the on-board software must be upgraded or modified, the new firmware can
be downloaded to the internal flash memory via the radio clock's serial port COM0.
There is no need to open the computer case and insert a new EPROM.
If the button behind a hole in the rear slot cover is pressed for approximately 2
seconds, a bootstrap loader is activated and waits for instructions from the serial port
COM0. A loader program shipped together with the file containing the image of the
new firmware sends the new firmware from one of the computer's serial ports to the
clock's serial port COM0. The bootstrap loader does not depend on the contents of the
flash memory, so if the update procedure is interrupted, it can easily be repeated.
The contents of the program memory will not be modified until the loader program
has sent the command to erase the flash memory. So if the button has been pressed
accidentally, the system will be ready to operate again after the computer has been
turned off an the on again.