Modem Remote Communications; Host Computer Remote Communications - Radyne DMD20 Installation And Operation Manual

DMD20 Universal Satellite Modem
The Terminal Mode uses eight "Screens," each of which have the basic contents of the three
modem monitor and control areas as set in the Front Panel matrix columns. This screen is used
for setting the parameters of the Modulator, Demodulator, Event, Alarm, Latched Alarm, Drop
Controls, Insert Controls, and Interface Areas.

4.9 Modem Remote Communications

4.9.1 Host Computer Remote Communications

Note: This specification is applicable to the DMD20, DMD15, DMD15L, DMD10 and
DMD10L Modems. Any reference to the DMD20 in this document can be applicable to any
one of these three modems.
Control and status messages are conveyed between the DMD20 and the subsidiary modems and
the host computer using packetized message blocks in accordance with a proprietary
communications specification. This communication is handled by the Radyne Link Level Protocol
(RLLP), which serves as a protocol 'wrapper' for the RM&C data. Complete information on
monitor and control software is contained in the following sections.
4.9.1.1 Protocol Structure
When new features are added to Radyne ComStream Corporation
equipment, the control parameters are appended to the end of the Non-
Volatile Section of the Remote Communications Specification, and status
of the features, if any, are added at the end of the Volatile Section. If a
remote M&C queries two pieces of Radyne ComStream Corporation
equipment with different revision software, they could respond with two
different sized packets. The remote M&C must make use of the non-
volatile count value to index to the start of the Volatile Section. If the
remote M&C is not aware of the newly added features to the product, it
should disregard the parameters at the end of the Non-Volatile Section
and index to the start of the Volatile Section.
Before creating any software based on the information contained in this
document, contact the Radyne ComStream Corporation Customer
Service Department at (602) 437-9620 to find out if the software revision
for that piece of equipment is current and that no new features have been
added since the release of this document.
The Communications Specification (COMMSPEC) defines the interaction of computer resident
Monitor and Control Software used in satellite earth station equipment such as modems,
redundancy switches, multiplexers, and other ancillary support gear. Communication is bi-
directional, and is normally established on one or more full-duplex 9600-baud multi-drop control
buses that conform to EIA Standard RS-485.
TM103 – Rev. 1.1
User Interfaces
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