Symmetricom 1100 User Manual

Chapter 5 Testing the TimeProvider

To test the ability of the TimeProvider to switch references, you perform a two-step 
test:

Connect appropriate reference inputs to the TimeProvider.

Create a fault on the selected reference signal and observe that the 
TimeProvider changes to the appropriate secondary input.

To test the reference switching:

1. Connect a suitable reference signal to the PRS input and a second reference 

signal to the INP1 input. Wait for the Qualified LEDs for both inputs to turn green 
and for the Active LED to light on the PRS input.

2. Issue the 

ED-EQPT::PRS:::INSTATE=DISABLE;

 command to disable the PRS 

input and force the TimeProvider to switch to the INP1 reference. 

3. Observe that the Active LED changes from the original input to the secondary 

input (PRS to INP1 or INP1 to PRS).

When the TimeProvider is in the non-revertive operating mode, the input reference 
signal does not revert to the original input after it recovers from an error condition.

The TimeProvider is in non-revertive mode when the QLEVEL parameter for INP1, 
INP2, and PRS inputs is set to the same value, and the PRIORITY parameters for 
the same inputs are set to the same level.

To test the non-revertive operating mode, perform the following steps:

1. Define the non-revertive mode by setting the QLEVEL and PRIORITY 

parameters to appropriate values. See 

112, and 

, on page 113, for further information.

2. Provision and connect appropriate reference inputs to the TimeProvider.

3. Create a fault on the selected reference signal and observe that the 

TimeProvider changes to the appropriate secondary input.

4. Remove the fault on the initial reference signal and observe that the 

TimeProvider does not revert to that initial reference input. The event log 
indicates that the reference signal is no longer in fault.