MICROTRONIX DX-2200, User Manual

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DX-2200
– SD/HD-SDI Text & Graphics Inserter – User Manual
Page 74 of 103
Command Description
CSF-400 to adjust the time in GPS field 59 by -400 milliseconds
The CFS command also accepts arguments followed by S, M, and H to set adjustments
in units or seconds, minutes, or hours. Decimal points are not permitted, but offsets in
hours, minutes, seconds and milliseconds can be combined in the command. Each
adjustment can
have a sign ‘+’ or ‘-‘. If no sign is provided the adjustment is taken as
positive, but when the sign is provided, it is sticky and applies to all subsequent
arguments until a new sign is found.
For example:
•
CSF-2h30m
– specifies an offset of -2:30:00
•
CSF-2h+30m
– specifies an adjustment of -2 hours + 30 minutes for a total
adjustment of -1:30:00.
•
CSF2h30m
– species an adjustment of +2:30:00
•
CSF5h400
– specifies an adjustment of 5:00:00.4 (five hours and 400
milliseconds).
The total adjustment allowed has a limit of 24 hours regardless of how it is specified.
Notes about time adjustment:
GPS data on the overlay is updated when data is received. If the adjusted time in field
59 is displayed on the overlay, and a correction of for example 400 milliseconds is used
with a GPS that updates once per second, the times on the overlay will be displayed as
03:31:20.4, 03:31:21.4, 03:31:22.4, etc. which may not be desirable. If a GPS with a
faster update rate and time resolution of 0.1 second were used instead, the output would
count as expected.
CSMn
Frame Counter synchronization mode.
After the frame counter time clock has been set, it runs from a crystal oscillator on the
DX-2200 and will gradually drift from real time. Synchronization modes provide a method
to keep the time clock synchronized with the GPS.
n = 0 - no synchronization. The frame counter time clock runs independently.
n = 1 - monitor GPS time and make micro-adjustments to the frame counter time clock to
track the GPS time. If the error is found to exceed the error threshold, the time clock is
re-set from the GPS time.
n = 2
– monitor and GPS time and re-set the time clock when the error exceeds the
threshold set by the CSR command.
CSRttt
Set the error threshold in milliseconds for performing a set of the frame counter time
clock. The default is 100 milliseconds. The frame counter time clock is compared to the
adjusted GPS time in GPS data field 59. If the error in the clock is found to be greater
than the threshold, the GPS time is used to set the clock.
CSS
Set the Frame Counter time clock when the next GPS time message is received. The
clock is set based on the adjusted time in GPS data field 59
4.8.1.14.4.1 GPS Data Display Example:
The following commands 7 data items at the top of the overlay and are intended for use with 720p video and
the Garmin GPS18xLVC receiver. To provide the necessary data for this example, the GPS should be
configured to output $GPGGA, $GPRMC, and $GPVTG sentences.