Dolby Laboratories S01/13621 - Manual (Page 32)

Dolby Installation Guidelines Hot Standby and Alarms
4-2
Figure 4-1 Hot Standby Operation of the DP569
For further security, pins 1 and 9 (ground) of the GPI/O ports can be used to control a
unit fault alert. If pin 1 goes “low,” then a power supply or hardware fault has occurred.
These can be used on both the encoders so that a faulty standby encoder can be identified
before it is required. Pins 3, 4, and 9 can also be used to ascertain whether the unit is
producing an encoded output, and trigger a warning on the console or monitor system.
4.4 DP570
The DP570 has fixed connections on the GP output for fault and error conditions
(pins 2 and 3, respectively). For critical live applications, the system design should be
such that the DP570 is only part of the monitor path or that these pins can be used to
trigger routing to bypass the main audio around the DP570.
4.5 DP571
The status port can be used to control a router, console, or other switching device in
the event of a unit failure. Pins 4, 5, and 9 (ground) can be used to check whether a
unit is operational. If pin 4 or 5 goes “low,” then either the system is not operational,
a hardware fault has occurred, or power has been lost to the unit. By monitoring these
pins on both the units, an operator can be alerted to problems with either unit.
4.6 DP572
The DP572 can be used in the same way as the DP571.