User's Manual

Digital ATSC Exciter-Modulator System Chapter 2,
Installation and Operating Instructions
Axcera Axciter, Rev. 0 11
SMPTE 310 Connection
The SMPTE 310 input receives a serial ATSC bitstream at a data rate of
19.392658 megabits per second. Line code is biphase mark. Signal amplitude
should be 800 millivolts peak to peak when terminated in a 75 ohm load.
The SMPTE 310 signal is internally regenerated and reclocked by the Axciter
modulator, and is available for testing or other uses at the connectors on the
rear panel.
IF Output Connection
The IF output is available on the rear connector labeled IF OUT. A sample of
the IF can be made available on the front panel. This sample should only be
used for test purposes and not for the primary IF output.
10 MHz Reference Connection
The modulator allows for the use of a 10 MHz external reference. If precise
frequency control is required, an external 10 MHz reference from a highly
stable source (such as a rubidium standard or GPS) may be applied to the
Axciter. With the external 10 MHz present, the internal 10 MHz OCXO is phase
locked to the high accuracy external reference.
1 PPS Reference Connection
Used for Single Frequency Network applications only.
Rear Panel LEDs
The rear panel of the modulator has an LED next to each coaxial connector.
During operation, a green LED next to the connector means that the signal is
present. A red LED means that the signal is absent or in a fault condition. A
dark LED means that the signal is not being used.
Graphical User Interface
The front panel of the modulator includes a color LCD that shows a wide range
of information about the operation of the Axciter modulator and the
upconverter. Details in the next section.
User Interface
This section describes the user interface, which is implemented as a graphical
set of screens following a menu structure. These screens are displayed on the
LCD screen on the front panel of the Axciter.
Topics include:
§ Navigating the user interface
§ Screen Displays and Details
§ User Interface Conventions
Navigating the User Interface
Each screen can contain a number of soft buttons, fields, graphs, and values.
The soft buttons along the right side of the screen display the function of the
corresponding adjacent front panel buttons. (NOTE: It is not a touch screen).
The primary function for these soft buttons is navigation between screens.