Toshiba Strata DK 280 Installation Manual page 640

DK280
DIGITAL
TELEPHONE
ELECTRONK
,
TELEPHONE
STANDARD
TELEPHONE
RCTU PCB
SYNCHRONIZATION
CIRCUIT
AI
4 IL
RDTUI (PRIMAR' t REF)
ION -
;
- I-----
-i
=
I
3Y REF)
ION -
I
;
SPAN
LINE 1
SPAN
INE 3
L
Ti SPAN CLOCK NOT
SYNCHRONIZED
PROPERLY WITH
STRATUM 1
CLOCK SOURCE
General Notes:
l
Primary Reference Syncronization:
In this diagram RDTUI is the primary reference, its synchronization circuit sends the clock reference
from the TELCO Tl span to the DK280, to the RCTUI synchronization circuit, via RDTUI Software
Switch (SS). The RCTU clock synchronizes the DK280 digital transmission voice path (via RCTU time
switch) to the TELCO/STRATUMl clock source.
l
Secondary Reference Switch-Over:
If the primary reference Tl (RDTUI) fails, the DK280 will automatically open the RDTUI primary
synchronization circuit (SSt) and close the RDTU2 secondary synchronization circuit (SS2). At this
time, the DK280 digital voice path will be synchronized to the AT&T/STRATUM1 clock source.
10 Slip example:
In the above diagram the "Other Tl Provider" is not synchronized to the STRATUM1 clock source
properly - Slip problems will occur on RDTU3 Tl channels.
Figure 11-l 2
RDTU Primary/Secondary Reference Block Diagram
11-16
January 1996