Operating Modes - Symmetricom TimeProvider 1000 User Manual

Chapter 1 Overview of the TimeProvider

Operating Modes

Operating Modes
You can configure the TimeProvider to operate in one of three modes:
Synchronization Supply Unit (SSU), Subtending (SUB) as defined by Telcordia
GR-378 Section 7, or Primary Reference Receiver (PRR) when the GPS input is
available. Each mode is unique in its operation, and is defined in the following
paragraphs.
SSU Mode
This is the TimeProvider's default operating mode. Valid signals on the PRS, INP1,
INP2, or GPS connectors can be selected as the system reference. In this mode,
the INP1 and INP2 inputs cannot be provisioned to receive Composite Clock (CC)
signals, including JCC or JCC4. The method of selecting the system reference is
described in
SUB Mode
This mode allows the TimeProvider to operate as a Remote shelf where phase is
critical. When you select the SUB mode, INP1 and INP2 are automatically set for
CC inputs (including JCC and JCC4). Outputs provisioned for CC are phase-aligned
with the selected CC input reference. Other output types comply with G.703 and
GR-1244.
To configure the TimeProvider for Subtending mode, see
on page 96.
PRR Mode
In PRR mode, the GPS is automatically selected as the system reference input.
This requires that you connect a GPS signal through the TPIU to the TimeProvider
using the provided interconnect cable. This mode complies with ITU-T G.811 and
Telcordia GR-2830 requirements for Primary Reference Receivers/Clocks. Valid
signals on the PRS, INP1, or INP2 connectors are used in conjunction with BesTime
to extend compliance with GR-2830/G.812 standards.
The PRR mode uses Symmetricom's BesTime servo control that allows the
TimeProvider to continue providing outputs in case GPS tracking is lost, the GPS
data loses integrity, or if the IMC is removed from the shelf. BesTime, on page 39
provides more information on the BesTime technology.
To configure the TimeProvider for PRR mode, see
page 96.
24 TimeProvider User's Guide
Selecting the Input, on page 32.
Setting the System
Setting the System Mode, on
097-58001-02 Revision C – August 2005
Mode,