6 software compatibility – Comtech EF Data SFC1800A User Manual
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SFC1800A Synthesized Frequency Upconverter
User Interfaces
TM111 – Rev. 1.0
4-25
Table 4-6. 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
06
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, DM240
23
Reserved for future equipment types
24 – 31
The following multi-drop override IDs are device-type specific, with the exception of
"BROADCAST". These are summarized in Table 4-6 with ID values expressed in decimal
notation:
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 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.”
4.4.2.6 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.