Table of Contents
Advertisement
Multi-Band Transceiver System
Remote Command
RS-485 (full duplex) summary:
Two differential pairs
Controller-to-target pair
Target-to-controller pair
A.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.3 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 format is fixed at
8 data bits, no parity, and 1 stop bit. Only two (2) baud rates are supported: 9600 baud and 19200
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.
A–2
Revision 0
MN/MBT4000B.IOM
Advertisement
Table of Contents
