Operating instructions

DVB3030/DVB3030L Digital Video Broadcast Modulator User Interfaces
TM052 - Rev. 3.5 4-27
Table B-3. Broadcast IDs
DIRECTLY-ADDRESSED EQUIPMENT MULTI-DROP OVERRIDE ID
Broadcast (all directly-linked devices) 00
DMD-3000/4000, 4500 or 5000 Mod Section, DMD15 01
DMD-3000/4000, 4500 or 5000 Demod Section, DMD15 02
RCU-340 1:1 Switch 03
RCS-780 1:N Switch 04
RMUX-340 Cross-Connect Multiplexer 05
CDS-780 Clock Distribution System 05
SOM-340 Second Order Multiplexer 07
DMD-4500/5000 Modulator Section 08
DMD-4500/5000 Demodulator Section 09
RCU-5000 M:N Switch 10
DMD15 Modulator 20
DMD15 Demodulator 21
DMD15 Modem 22
DVB3030 Video Modulator 23
Reserved for future equipment types 24 - 31
Note that multi-drop override ID 01 can be used interchangeably to broadcast a message to a
DMD-3000/4000 modem, a DMD-4500/5000, a DMD15 modem, or a DVB3030. Radyne Corp.
recommends that the multi-drop override IDs be issued only during system configuration as a
bus test tool by experienced programmers, and that they not be included in run-time software. It
is also advantageous to consider the use of multiple bus systems where warranted by a
moderate to large equipment complement.
Therefore, if a DMD15 Modulator is queried for its equipment type identifier, it will return a "20"
and DMD15 Demodulator will return a "21". A DMD15 Modem will also return an "22". A
DVB3030 Video Modulator will return a “23.”
4.3.7 Software Compatibility
The COMMSPEC, operating in conjunction within the RLLP shell, provides for full forward and
backward software compatibility independent of the software version in use. New features are
appended to the end of the DATA field without OPCODE changes. Older software simply
discards the data as extraneous information without functional impairment for backward
compatibility.
If new device-resident or M&C software receives a message related to an old software
version, new information and processes are not damaged or affected by the omission of data.
The implementation of forward and backward software compatibility often, but not always,
requires the addition of new Opcodes. Each new function requires a new Opcode assignment if
forward and backward compatibility cannot be attained by other means.