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164 TimeHub 5500 User’s Guide
097-55501-01 Revision M – January 2009
Chapter 4 Testing and Configuring the TimeHub
Provisioning Inputs on a Master Shelf
If the “Q” LED is not lit and the “E” LED is lit, check for:
– No signal. Check the configuration at the source.
– Signal is present but it isn't an ESF-framed DS1. DS1 SF-framed (also
known as D4 framing) signals are not capable of SSM encoding. Change
the configuration at the source so the framing of this signal is ESF.
If the “Q” LED is lit, a shelf can now use the DS1 input 1 signal as an SSM
source. The “A” (Active) LED indicates that this input is currently being used as
the source of SSM information for the shelf. When lit, any outputs carrying SSM
are encoded with the same SSM value that is being decoded on this input. The
“A” LED illuminates when the following condition is present:
– There isn't also a qualified SSM input in the DS1 input 2 row. If there is, it
is possible that this input will be selected as the active SSM source instead
of the DS1 input 1 signal. When both SSM inputs are valid the one that will
be used is determined by the setting of the PRIORITY keyword. The
default is that the DS1-1 input has the higher priority, so it will be selected
when both inputs are qualified. See TL1 manual for details.
The general TL1 command format for enabling or disabling an input is:
ED-SYNC::CLK-a:<ctag>:::ENABLE=b;
where a = 0 – 4 to identify the input (PRS=0)
b = Y to enable or N to disable the input.
Based on the inputs you will actually use, enable or disable inputs as
appropriate. For example, to disable DS1 input 2, issue the command:
ED-SYNC::CLK-2:SV343:::ENABLE=N;
To retrieve the status of an input, issue the command:
RTRV-SYNC::CLK-a:SV343:::PARAMETER=ENABLE;
which shows if the selected input is enabled or disabled.
6. Set PRS Input frequency, if needed. The PRS reference frequency can be set to
expect either a 5 or 10 MHz input. The default is 10 MHz. If necessary, change
the setting.
To set the PRS Frequency to 5 MHz, issue the following command:
ED-SYNC::CLK-0:SV347:::PRC5MHZ=Y;
Set this value to N when the expected PRS Frequency is 10 MHz.