Lexicon MC-12 V3.0 - SERIAL COMMUNICATIONS PROTOCOL DEFINITION REV 1-5 - 4 General Description

Lexicon, Inc.
MC-12 Serial Communications Protocol Printed on: 08/18/03
© 2003 Lexicon, Inc. All rights reserved. 7 of 94
ACK Acknowledge
NAK No Acknowledge
FPD Front Panel Display
4 General Description
The intention of the MC-12 serial port and protocol communication is for an external connected HOST to
control and obtain status from the MC-12. The protocol has been designed to focus on two specific goals.
The first is HOST uploading and downloading of MC-12 configuration, and system/effect setups. The
second is HOST control of basic user adjustable parameters.(i.e. input, volume, balance…)
The MC-12 uses simple notification, command, response and acknowledgment packets to have
communication transactions with a given HOST. This protocol is designed for point to point
communication between a HOST and MC-12. The MC-12 Protocol is a 3 layered system. The MC-12
serial protocol allows for the MC-12, or the HOST, to initiate a communication transaction. Most
transactions are initiated by the HOST. MC-12 then responds to the HOST command with either a response
or acknowledgment packet. There are a few asynchronous notifications that MC-12 initiates indicating
system changes. Each transaction initiated must wait for a corresponding response before initiating the next
transmission.
The 3 protocol layers are: Physical, Data Link, and Application Layers.
The MC-12 Serial Protocol attempts to be as backward compatible with the MC-1 as possible. This
document will try to inform the user/programmer of the consistencies and differences between the MC-1
protocol and the MC-12 protocol. The basic structure of the protocol has not changed. A number of
command/responses/notifications packets have been implemented exactly as they were in the MC-1. These
commands may not fully exercise the functionality of the MC-12 (i.e. Mc-1 has 8 inputs that have been
mapped to 8 of the 12 inputs on the MC-12, MC-1 IR codes are not the same as MC-12 IR codes) In the
case of these commands additional MC-12 commands have been added to fully implement the MC-12
functionality. In addition, some the internal structure of the MC-12 has forced the protocol to be unable to
support some MC-1 commands. These commands have been totally replaced with new commands that
provide more control over the MC-12 than was capable in the MC-1. (Parameter Set/Get commands)
Physical Layer (RS232)
Data Link Layer
Application Layer
CD VOL
Lexicon MC-12
HOST
Rs-232 Serial Link