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8.1 RTC (Real Time Clock)
A backup clock, called the RTC (Real Time Clock) is included in the DXD. It is set at the factory (date & time) and runs
continuously, even when the unit is turned off as it is powered by an internal battery.
The DXD uses the date & time information from the RTC just after power up and transfers it to
the main TOD (System Time). When locking to a new reference, if that reference does not
have date & time, the TOD simply continues counting along its current time sequence; if it has
date & time, that information is transferred to the TOD.
Although the RTC is set at the factory, it can also be set manually by the operator or be
updated automatically (if GPS is available) via the Real Time Clock menu (menu 7.2).
8.2 Time Jam
The BNC inputs can accept Word Clock, AES, Video Sync or 10 MHz. As none of those signals has date and time information,
when one is selected as reference, the DXD-8 can be set to receive time information from another source. Current choices are
PTP and GPS. Since the DXD-8 can only lock to one reference at one time, this would take place as a Time Jam, meaning that
the DXD-8's TOD will be reset to the time of the master source before locking to the BNC input.
8.2.1 TIME JAM TO PTP
When PTP is selected as the source of TIME JAM (menu 1.2), the DXD-8 will first lock its internal Time of Day clock to PTP.
When that is achieved, the DXD-8 will release the PTP Lock and revert to the BNC source selected in the reference menu.
Reasons to PTP time jam DXD-8's include:
• Locking to a common video reference (e.g. NTSC) and wanting all of the cross-frame outputs (25 etc.) to be in correct phase
(and epoch), as well as wordclocks and AES.
• In a primarily legacy application this is the way to increase the number of legacy outputs and have them all in phase.
• With a timecode license wanting TOD timecode outputs to be in sync, and with correct cross-framing where applicable.
8.2.1.1 What is the sequence of a complete Time Jam to PTP?
1. LOCK TO PTP: The DXD-8 Lock status indicates HOLD / PTP SYNC on dark pink background.
2. CONFIRMATION: A message confirms that the date and time information has been transferred to the internal Time
of Day successfully (clearing of this message is required).
3. LOCK TO THE BNC INPUT: The DXD-8 indicates it is locked to the BNC reference, Input a / Video in this example.
4. SYSTEM TIME UPDATED: The System Time now indicates the same time as the PTP source
8.2.1.2 What is required for a Time Jam to PTP?
1. Reference must be BNC A or BNC B (menu 1.1). That BNC input must be set properly in menus 2.1 and/or 3.1.
2. The PTP port must be set as the BNC INPUT TIME JAM SOURCE (menu 1.2). The port will now show as set for Time
Jam [BNC Inputs] in menu 5.1 (blue letters indicate status and cannot be altered)
3. The PTP domain of the Time Jam Port must be set to the same domain as the PTP source in the proper menu (Menu 5.5)
8.2.2 TIME JAM TO GPS
With the DXD/GPS option installed, GPS can be selected as a source for a Time Jam in menu 1.2. The sequence is similar to
the Time Jam to PTP. After the DXD has locked its internal Time of Day clock to GPS, it locks to the BNC source selected in
menu 1.1.
Note: Be sure the GPS Receiver is no longer in WARM UP state as it will not be used for Time of Day in that condition.
DXD/PTP/GPS User Manual (rev 2.10)
TIME JAM
A Time Jam to PTP has
completed successfully
Press Any Key to Exit
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