Planning The Timing; Aggregate Timing - Ultra electronics VersaMux-4000 Operations & Installation Manual

Chapter 4: Getting Started

Planning the Timing

Aggregate Timing

Figure 4-14
Part No. 24001157
Revision C
The VersaMux-4000 is equipped with various timing options which enable it to
adapt to almost any network configuration. Your configuration may vary due to
your network design. This section provides an overview of typical VersaMux-4000
clocking configurations as a guide to adapting the VersaMux-4000 to your
network.
The VersaMux-4000 can accept timing from one of the following sources:
• Aggregate (NRZ interface)
• Any of the Port interfaces (up to four choices)
• External Clock Input
• The VersaMux-4000 internal oscillator
The VersaMux-4000 NRZ interface (aggregate) is software set to either DTE or DCE
(Mode parameter in the Aggregate sub-menu). This directly affects the Transmit
Clock Source operation (TxClkSrc parameter in the Aggregate sub-menu).
Selecting the Internal option (for the Clk-Ref parameter) causes the VersaMux-
4000 to develop the reference from its internal oscillator (accuracy +/- 20-ppm).
In most cases the VersaMux-4000, in DTE mode, will recover the master clock (also
known as the Primary Reference Source or PRS) from the transmission uplink
equipment via the aggregate interface (NRZ).
Aggregate Timing, VersaMux = DTE
Figure 4-14 illustrates a typical timing configuration where the VersaMux-4000
recovers its master clock from the Rx Clock (Receiver Signal Element Timing - DCE
Source) on the aggregate interface (ClkRef parameter set to Aggregate). It uses
the Tx Clock signal from the DCE device (Transmit Signal Element Timing- DCE
Source) to clock the Transmitted Data out to the DCE (TxClkSrc parameter set to
TxClkIn). In addition, the VersaMux-400 uses the Tx Clock DCE signal to generate
the Tx Clock DTE signal to the DCE (Transmit Signal Element Timing- DTE Source).
Port Interfaces
VersaMux-4000 (DTE) Typical Network Timing Configuration
VersaMux-4000 Operation & Installation Guide
VersaMux-4000 (DTE)
Mode = DTE
ClkRef = Aggregate
TxClkSrc = TxClkIn
ClkRef

Planning the Timing

DCE Device
(IE: Satellite
Modem)
Tx Clock (DCE)
Primary
Tx Clock (DTE)
Reference
Transmitted Data
Source (PRS)
Rx Clock (DCE)
Rx Data
NRZ Interface
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