Comtech EF Data SFC1800A - Manual (Page 44)

User Interfaces SFC1800A Synthesized Frequency Upconverter
4-20 TM111 - Rev. 1.0
4.4.2 RLLP Serial Protocol
The Radyne Link Level Protocol (RLLP) is an alternative serial protocol used in conjunction with
the remote port.
4.4.2.1 RLLP Protocol Structure
When new features are added to Radyne 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 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 Customer Service Department (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 multi-drop control buses that
conform to EIA Standard RS-485.
Each piece of earth station equipment on a control bus has a unique physical address, which is
assigned during station setup/configuration or prior to shipment. Valid decimal addresses on one
control bus range from 032 - 255 for a total of up to 224 devices per bus. Address 255 of each
control bus is usually reserved for the M&C computer.