Cheetah 64NEX Digital Video Router
Publication 81-9059-0685-0, Rev. A
March 2011
Proprietary Information of PESA
4-10
4.9.3
System Control Alarm Connector
This three-pin connector, illustrated in Figure 4-7, provides an interface for an external,
customer-supplied, system control alarm (alarm contact locations are also shown).
F
IGURE
4-7
System Control Alarm Connector
The system controller initiates a system alarm when the controller is in reset and when the
standby controller is gathering configuration information from the primary controller. During an
alarm condition, an optically isolated, electronically closed circuit (see Figure 4-8 on next page)
exists between contacts 3 and 1 for Controller A (top) and contacts 2 and 1 for Controller B
(bottom). This circuit acts as a switch to trigger an optional external alarm in the event of a
controller fault or failure. The controller alarm circuit supplies an electronic contact closure, but
does not provide a voltage to the external alarm.
The Customer-supplied alarm circuit voltage to this connector must not
exceed 12VDC and the associated amperage must not exceed 10mA.
The alarm is activated if any of the following system controller software conditions exist:
•
Encounters an interrupt that it does not expect or can not process.
•
Is unable to synchronize with the second system controller (dual controllers).
•
Does not get the configuration from the active system controller (dual controllers)
The customer supplied external alarm circuit is connected with a cable constructed as shown in
Figure 4-8.
(+)
(-)
S
S
YSTEM
C
ONTROL
A
LARM
C
ONNECTOR
Summary of Contents for 64NEX
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