Motorola T1/E1 ユーザーズマニュアル

Canopy  T1/E1 Multiplexer 

 

 

 

 

 

 

September 2004 

 

 

 

 

 

 

     

      T1/E1 Multiplexer FPGA Version 3.4 

 
 

 

Page 22 of 73 

Stratum 1 
Clock 

1 x10

-11

1 every 72 days 

Gateway Office 

Stratum 2 
Clock 

1x10

-10

1 every 3.5 hours 

Toll Center  

Stratum 3 
Clock 

3.7x10

-7

1 every 6 minutes  
or  

255 in 24 hours 

Central Office 

Stratum 4 
Clock 

3.2x10

-6

Up to 1 frame slip 
every 4 seconds in 
free-run 

Customer Premises Equipment 
(PBX, Channel Banks, Routers) 

 

The Canopy T1/E1 Multiplexer does not have an internal oscillator. Therefore, the unit 
must be synchronized to a T1/E1 bit stream in order to accurately pass T1/E1 traffic.  The 
Canopy T1/E1 Multiplexer may be configured to synchronize to a near-end or far-end 
Canopy T1/E1 Multiplexer. 

The clock on each Canopy T1/E1 Multiplexer must be correctly configured to prevent 
frame slips.  Each of the four (4) T1/E1 ports may be configured as the Master clock 
source or the Secondary clock source.  Any port may be set to Master and any port may 
be set to Secondary, however there may only be one (1) Master and one (1) Secondary 
clock setting per unit.   

Note: If neither the Master or Slave port is active, then the system will start at Port 1 and 
search in logical order until it finds an active T1/E1 port, at which time it will assume this 
to be the Master clock source.   

Two scenarios are shown below, one scenario with Port 1 set to Master and Port 2 set to 
Secondary. The second scenario shows Port 1 set to Secondary and Port 3 set to 
Master. 

 

Issue 3