Comtech EF Data SDM-2020 - Manual (Page 65)

6–1
Chapter 6. FRONT PANEL
OPERATION
This appendix describes the front panel operation for demodulator.
6.1 Introduction
The SDM-2020 demodulator has three general modes of operation controlled by the DVB
Framing Type command in the Configuration Interface menu.
Refer to Table 6-1 for a description of the three modes.
Table 6-1. Mode Description
Mode Description
188 The demodulator receives a 204 byte satellite frame. The outgoing DVB/MPEG2
frame consists of 1 sync byte (047 hex) and 187 bytes of data after the Reed-
Solomon check bytes (16 bytes) are removed.
204 The demodulator receives a 204 satellite frame consisting of 1 sync byte (047),
plus 187 bytes of data and 16 bytes reserved for check bytes. The outgoing
frame contains 204 bytes.
None (187) In this mode there is no outgoing frame structure. The demodulator receives a
204 byte satellite frame and removes the 1 sync byte and 16 Reed-Solomon
check bytes.
Note: The satellite frame is always 204 bytes, and the data format exiting the data interface
depends upon the type of interface and the configuration selected. Control functions and status
readings are accessible through the front panel keypad/LCD display, or the rear panel remote
port.