Basic Protocol - Comtech EF Data LBC-4000 Installation And Operation Manual

LBC-4000 L-Band Up/Down Converter System
Remote Control
RS-485 (full duplex) summary:
Two differential pairs
Controller-to-target pair
Target-to-controller pair
A.1.2 RS-232
This is a much simpler configuration in which the controller device is connected directly
to the target via a two-wire-plus-ground connection. Controller-to-target data is carried,
via RS-232 electrical levels, on one conductor, and target-to-controller data is carried in
the other direction on the other conductor.
A.2 B P
ASIC ROTOCOL
Whether in RS-232 or RS-485 mode, all data is transmitted as asynchronous serial
characters, suitable for transmission and reception by a UART. The asynchronous
character formats are:
o
o
o
The following are the baud rates being supported: 1200, 2400, 4800, 9600, 19200, and
38400 baud.
All data is transmitted in framed packets. The host controller is assumed to be a PC or
ASCII dumb terminal, which is in charge of the process of monitor and control. The
controller is the only device that is permitted to initiate, at will, the transmission of data.
Targets are only permitted to transmit when they have been specifically instructed to do
so by the controller.
All bytes within a packet are printable ASCII characters, less than ASCII code 127. In
this context, the Carriage Return and Line Feed characters are considered printable.
All messages from controller to target require a response (with one exception). This will
be either to return data that has been requested by the controller, or to acknowledge
reception of an instruction to change the configuration of the target. The exception to this
is when the controller broadcasts a message (such as Set time/date) using Address 0,
when the target is set to RS-485 mode.
One pair for controller to target.
One pair for target to controller.
One line driver (controller) and all targets have line-
receivers.
One line receiver (controller) and all targets have tri-
state drivers.
8 data bits, no parity, and 1 stop bit (8NI)
7 data bits, even parity, and 2 stop bits (7E2)
7 data bits, odd parity, and 2 stop bits (7O2)
A-2
MN/LBC4000.IOM
Revision 2