ADTRAN T1-FT1 user manual TSU Clock Sources, Network Timed

Chapter 1. Introduction

TSU Clock Sources

The TSU is operable from various clock sources permitting it to perform properly in many different applications. The network interface clocking options are set by using the Network (NI) Configuration menu options. There are three clock source options available.

•Network

•DTE Timed

•Internal Timing

The clocking option selected always designates the clock source for transmission. Clocking necessary for receiving data will always be recovered from incoming data.

Network Timed

The network is the source of timing. The received data clocking is looped back to the network where it is used to determine the transmission timing. This option is also referred to as looped timed as the transmission clock is derived from the received clock. See Figure 1-4.

	OSC
T1 XMIT
( D S U )	Network
T1 Receive	Interface
	NX56K/64K
	DTE CLOCK
	DTE

Figure 1-4. Network Timed Clock Source

1-8 TSU User Manual 61200060L1-1