Vanguard Managed Solutions 7300 Series installation manual Clocking Example

Vanguard 7300 Cards

•There is one Card Clock on each card. Card Clock allows you to lock multiple Groups together and must be used for voice ports.

•There is one System Clock bus in the node, which allows you to lock multiple cards together.

You set each group on a card (four ports) as to whether it participates in Card Clock or not and you set the card as to whether it participates in System Clock.

Figure 2-25shows this arrangement, with X’s showing where the connections points are located.

	T1/E1 Cards
Port 12
Port 9	System
	Clock
Port 8	Bus
Port 5	Card
Port 4	Clock
	Bus
Port 1
Group
Clock
Bus

Figure 2-25. Clocking Example

If you have an external device providing a clock to a port, that clock, if it is the first, highest priority clock in the group will drive the Group clock. You can configure Group Clock to drive Card Clock. Card Clock can then be used to synchronize different Groups and/or to drive System Clock. System clock can be used to synchronize multiple cards.

If you are running Voice, the PCM encoded port must be on ports 1-2 and the Group Clock (for group 1) must be set to Card Clock.

Port Timing		Group Clock set to		Group Clock set to Card			Card Clock set to
		Group Clock			Clock		System Clock
Internal	All four ports are isolated		Card Clock drives Group			System Clock drives Card
	from other groups. Port used		Clock's transmit.			Clock's transmit.
	Group Clock for transmit				Note		Note
	and expects the remote
			Group must be set to Card			Do not set all ports to
	device to return this clock.
			Clock for voice connections.			Internal when set for system
		Note
						clock or there will not be a
	If all ports in the group are					master clock source and
	internal, the ports will uses					connections will not operate
	Card Clock for their trans-					properly.
	mit.

Vanguard 7300 Enclosures and Components 2-37