ADTRAN TSU 120e - Manual (Page 68)

Chapter 5. Configuration Menu
5-10 TSU 120 User Manual 61202129L1-1
Secondary Timing
The secondary interface is the source of timing. The TSU 120
uses the clock derived by the secondary interface for transmis-
sion timing and the receive signal timing. See Figure 5-6.
Either a DSX-1 Option Module or a Drop and Insert Option
Module must be installed in the TSU 120 for this mode to func-
tion.
Figure 5-6. Secondary Timing
DTE
OSC
Secondary
Interface
(SI)
( O P T I O N )
Network
Interface
(NI)
T1 XMIT
T1 Receive
( D S 1 )
Nx56/64
DTE CLOCK
DSX
PBX
PBX
(IO PB)