Symmetricom 1000 User Manual

Chapter 4 Provisioning the TimeProvider

ED-SYNC::INP1:TS1000::FRMTYPE=ESF;

TP-SSU 03-10-24 10:50:05

A 1181 REPT EVT

“INP1,T1:NA,FRMTYPE,NSA,03-10-24 10-50-05:\"INPUT FRAMING 

TYPE HAS CHANGED,ESF\””

;

The TimeProvider can determine which input reference signal has the highest 
quality. When the active reference signal falls below a preset quality level, the 
TimeProvider can automatically switch to the next highest input reference signal. To 
use this feature, you must enable Automatic switching.

You can also use the performance monitoring features to automatically switch the 
input reference signal when user-defined performance thresholds are crossed. See 

, on page 116 for more information on setting 

and using performance monitoring commands.

Automatic Return to a Higher Priority Reference
When the REFMODE parameter is provisioned to AUTO, the system reference 
switches when the input signal is disqualified. When the input signal is re-qualified, 
the TimeProvider can either keep the current reference or switch back to the 
re-qualified signal. The first case, keeping the current reference, is also known as 
“non-revertive” mode; the second case, switching back to the re-qualified input, is 
known as revertive mode.

The QLEVEL (see 

, on page 113) parameters work together with 

SSMs to determine the switching strategy for the inputs when the unit is in the SSU 
mode. If the active/primary input becomes unavailable, the switching strategy 
determines which input to use: the TimeProvider uses the input with the next 
highest QLEVEL. If all inputs have the same QLEVEL, then the TimeProvider uses 
the input with the highest PRIORITY.

To provision the TimeProvider as non-revertive, you must provision the 
user-assigned Priority Level on all inputs to the same value (1, 2, 3, or 4). To 
provision the TimeProvider as revertive, you provision any one of the inputs to a 
higher or lower Priority Level, with 1 being the highest priority.

INPp 
p = 1 | 2

FRMTYPE

2M (2.048 MHz) | CAS | 
CCS | D4 | ESF | 
1.544M | 6.312M | CC | 
JCC | JCC4 

Provisions the frame 
signal type used by 
the input. 

2M (E1)
ESF (T1)