Sync Functions - Promax MO-180 Manual De Usuario

4.6 SYNC functions

These set of functions control all synchronisation features of the MO-180. In the
following the available menu entries are described.
10 MHz reference
This applies to master MFN and SFN operation. In slave MFN operation the
modulator clock is always derived from the input TS rate. Several lock modes are
defined:
Ext SFN and master MFN. The modulator locks its circuitry to the external
10 MHz input. This might be for instance the clock obtained from the
GPS signal by an external professional GPS receiver.
Int Master MFN only. Use the internal 10 MHz TCXO for synchronisation.
Auto1 Master MFN only. The automatic switch over type 1 defaults to the
external 10 MHz reference, switching over to the internal TCXO when an
external reference is missing. Once the loss of the external 10 MHz
reference has triggered the switch over to the internal 10 MHz clock, the
10 MHz loss flag will remain active until a switch over back to the
external reference is forced by selecting Auto1 again.
Auto2 SFN and Master MFN. The automatic switch over type 2 works similarly
to Auto1. The only difference is that a loss of sync triggers the
switchover to a TS data derived clock which is locked to the incoming
HP stream as in MFN slave mode.
10 MHz Zin
The input impedance seen from the 10 MHz BNC connector can be set to 50 Ω
or to High Z (several MΩ).
1pps edge
In SFN operation this selects the active edge of the one pulse per second
signal. The rising edge is commonly used.
1pps Zin
In SFN operation, the input impedance seen from the 1pps BNC connector can
be set to 50 Ω or to High Z.
Page 26
USER'S MANUAL MO-180
04/2008