Vanguard Managed Solutions 7300 Series Clock Timing, Clocked Port as DCE Port as DTE, T1/E1 Card

Vanguard 7300 Cards

	Clock Timing
Timing
		The 7300 serial cards can be clocked Internal, External, ExtInt, and ExtLp with no
		restrictions between ports or speeds up to 8,196,000bps. These timing modes are the
		same as other standard Vanguard products. The recommended Timing configuration
		for all applications is ExtInt on the DCE side and ExtLp on the DTE side (except for
		X.21). This is required for all higher speed connections to work reliably.
		Clocked	7300 Port as DCE	7300 Port as DTE
		Internal	Uses an internal oscillator and	Uses an internal oscillator to pro-
			provides clock on both the Trans-	vide clock on the External Trans-
			mit and Receive clock lines.	mit Clock line. Expects a clock
				supplied by the attached device
				on Receive Clock line.
		External	Expects a clock on External	Expects a clock supplied by the
			Transmit Clock line supplied by	attached device on both Transmit
			the attached device. Uses an	and Receive Clock lines.
			internal oscillator to provide
			clock on the Receive Clock line.
		ExtInt	Uses an internal oscillator to pro-	N/A
			vide clock to the attached device
			on the Receive Clock line.
			Expects the attached device to
			loop the Receive Clock around
			and provide it on the External
			Transmit Clock line.
		ExtLP	N/A	Expects the attached device to
				provide a clock on Receive
				Clock line and will loop this
				clock around and provide it on
				the External Transmit Clock line.
T1/E1 Card
		The T1/E1 card has three groups of 4 ports (2 groups for an 8 port card). Each T1/E1
		card can have a maximum of 3 different time bases on a single 12 port card (2 for 8
		port cards), one on each of the groups.

The Time base for all four ports in each group must be the same, either from an external source within the group, another group, another card or an internal oscillator. You can set each port to Internal, Primary External (Prim_Ext), or Secondary External (Sec-Ext). This setting determines whether the attached device provides the timing or accepts timing from each port and also sets the priority of this clock.

•There are three types of clock buses in the node, Group Clock, Card Clock and System Clock. There are three Group Clock busses on each twelve-port card (two for 8 port cards), one for each group of four ports. This locks the timing of each of the four ports in a group together.

2-36 Vanguard 7300 Enclosures and Components