Lexicon MC-8 V1.0 - SERIAL COMMUNICATIONS PROTOCOL DEFINITION REV... User manual

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Serial Communications Protocol Definition
Project: MC-8/MC-8B
Updated: April 1, 2003
Software Version 1.0
Protocol Version:
Major rev 1
Minor rev 4
Lexicon, Inc.
3 Oak Park
Bedford, MA 01730-1413
[phone]

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Manufactured under license from Dolby Laboratories. “Dolby”, “Pro Logic”, and the double-D symbol are
trademarks of Dolby laboratories.
Lucasfilm and THX are trademarks or registered trademarks of Lucasfilm, Ltd.
© Lucasfilm, Ltd. & TM. Surround EX is a jointly developed technology of THX and Dolby Laboratories,
Inc. and is a trademark of Dolby Laboratories, Inc. All rights reserved. Used under authorization.
Manufactured under license from Digital Theater Systems, Inc. U.S. Pat. No. 5,451,942; 5,956,674;
5,974,380; 5,978,762 and other world-wide patents issued and pending. “DTS”, “DTS-ES Extended
Surround” and “Neo:6” are trademarks of Digital Theater Systems, Inc. © 1996, 2000 Digital Theater
Systems, Inc. All rights reserved.
“LOGIC7” and the LOGIC7 symbol are registered trademarks of Lexicon, Inc., a Harman International
Company.
© 2003 Lexicon, Inc. All rights reserved.
This document should not be construed as a commitment on the part of Lexicon, Inc. The information it
contains is subject to change without notice. Lexicon, Inc. assumes no responsibility for errors that may
appear within this document.
Lexicon, Inc.
3 Oak Park
Bedford, MA 01730-1413 USA
Tel [phone]
Fax [phone]
www.lexicon.com
Customer Support
Tel [phone]
Fax [phone] (Sales)
Fax [phone] (Service)
Lexicon Part No. 070-15332 Rev 0

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1Documents 5
1.1 Change List 5
2 Definitions 5
2.1 Protocol Version Cross-reference 5
3 Abbreviations 5
4 General Description 5
4.1 Physical Layer 7
4.2 Serial Port Driver 7
4.3 Errors 7
4.4 MC-8 Receive Buffer 7
4.5 MC-8 Hardware Verification 7
5 Data Link Layer 8
5.1 Errors 8
6 Application Layer 8
6.1 MC-8 Asynchronous Notification Packets 8
6.1.1 Wakeup Notification 9
6.1.2 Sleep Notification 9
6.1.3 Front Panel Display 9
6.1.4 MC-1 Parameter Change 10
6.1.5 MC-8 Parameter Notification by Id 11
6.2 Acknowledgment Packets 12
6.2.1 Acknowledge 12
6.2.2 No Acknowledge 13
6.3 Host Initiated Command Packets 13
6.3.1 Reset Unit 13
6.3.2 Restore 13
6.3.3 MC-1 Send IR Command 14
6.3.4 Get Unit Configuration 14
6.3.5 Get System Status 17
6.3.6 Get Zone 2 Status 19
6.3.7 Get Custom Name 20
6.3.8 Get Input Name by Id 20
6.3.9 Set System Volume 21
6.3.10 Set Main Balance 22
6.3.11 Set Front/Back Balance 23
6.3.12 Set Active Effect by Id 23
6.3.13 Set Zone2 Volume 24
6.3.14 Set Zone2 Left/Right Balance 25
6.3.15 Set Custom Name 25
6.3.16 Set Input Name by Id 26
6.3.17 Host Wakeup 27
6.3.18 Host Sleep 27
6.3.19 Get Communication Configuration 27
6.3.20 Set Communication Configuration 28
6.3.21 Set Mute 29
6.3.22 Send Display String Command 29
6.3.23 MC-8 Get Parameter Definition by Id 30
6.3.24 MC-8 Set Parameter Value by Id 32

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6.3.25 MC-8 Set Parameter Value by Id, No Run 34
6.3.26 MC-8 Get Unit Configuration 34
6.3.27 MC-8 Send IR Command 37
6.3.28 MC-8 Get Parameter Value by Id 37
6.3.29 MC-8 Set Parameter Notification by Id 38
6.3.30 MC-8 Parameter Get Value String by Id 39
6.3.31 MC-8 Clear All Parameter Notifications 40
6.3.32 MC-8 Get System Status 40
6.3.33 MC-8 Get Zone Status 42
6.3.34 MC-8 Set System Volume 43
6.3.35 MC-8 Set Main Balance 43
6.3.36 MC-8 Set Front/Back Balance 44
6.3.37 MC-8 Set Active Effect by Id 44
6.3.38 MC-8 Set Zone2 Volume 45
6.3.39 MC-8 Set Zone2 Left/Right Balance 45
6.3.40 MC-8 Get Input Name by Id 46
6.3.41 MC-8 Set Input Name by Id 47
Appendix A Command Codes 48
Appendix B Error Codes 50
Appendix C DC-2, MC-1 IR-Codes 51
Appendix D MC-8 IR Codes 52
Appendix E MC-1 Input Id’s 53
Appendix F MC-8 Input Ids 53
Appendix G Protocol Constants 53
Appendix H MC-8 to MC-1 Effect Map 54
Appendix I MC-1 to MC-8 Effect ID Map 55
Appendix J MC-8 Mode Ids 56
Appendix K Application Notes and Examples 57
6.4 Box initializations: 57
6.4.1 MC-8: 57
6.4.2 HOST: 57
6.5 Getting System Wide Status and Setup: 57
6.5 Downloading the System Setup to the 57
6.6 MC-8: 57
6.7 Simple System Control & System Status: 57
6.8 Examples: 57
6.8.1 MC-8 Get Unit Configuration 57
6.8.2 Send MC-8 IR Command Example 59
Appendix L MC8 V1.00 Parameter ID List 59

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1 Documents
The following documents should also be used with this document to understand how this protocol can be used with
an MC-8.
070-15481 Rev 0 Manual, Owner’s, MC-8/MC-8B
MC1/DC2 Serial Port Definition, Protocol Version 0.5
070-13227 MANUAL,OWNER'S,DC2
070-13278 MANUAL,OWNER'S,MC1
1.1 Change List
2 Definitions
User Parameter: A user changeable variable that stores a specific value that describes an operating
condition for the MC-8 system.
HOST: The device initiating or receiving the serial communication packets to/from the MC-8.
MC-8: The Lexicon product receiving or transmitting the serial communication packets to/from
the HOST.
Nonvolatile RAM: The area of memory in an MC-8 that stores users adjustable parameters. The Nonvolatile
RAM is battery backed, to maintain values during MC-8 power down.
2.1 Protocol Version Cross-reference
All references to MC-8 shall be valid for both the MC-8 and SDP-5 products unless specifically documented
otherwise. All references to MC-1 shall be valid for the MC-1, DC-2 and SDP-3 products unless specifically
documented otherwise.
3 Abbreviations
SOP Start of Packet
EOP End of Packet
ACK Acknowledge
NAK No Acknowledge
FPD Front Panel Display
4 General Description
The intention of the MC-8 serial port and protocol communication is for an external connected HOST to control and
obtain status from the MC-8. The protocol has been designed to focus on two specific goals. The first is HOST
uploading and downloading of MC-8 configuration, and system/effect setups. The second is HOST control of basic
user adjustable parameters.(i.e. input, volume, balance…)

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The MC-8 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-8. The MC-8 Protocol is a 3 layered system. The MC-8 serial protocol allows for the MC-8, or the HOST, to
initiate a communication transaction. Most transactions are initiated by the HOST. MC-8 then responds to the
HOST command with either a response or acknowledgment packet. There are a few asynchronous notifications that
MC-8 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-8 Serial Protocol attempts to be as backward compatible with the MC-1 as possible. The basic structure of
the protocol has not changed.
CD VOL
Lexicon MC-8
HOST
Rs-232 Serial Link

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4.1 Physical Layer
DB-9 RS232 Connector
Note: The wiring requirements for a 9 pin to 9 pin serial connection, are a male to female straight through cable.
4.2 Serial Port Driver
MC-8 serial port has been setup to operate as follows:
Operating Mode: Full Duplex
Baud rate: 19.2K baud
Data Size: 8 bits (1 byte)
Parity: Odd
Stop Bits: 1
Hardware Handshaking: None
4.3 Errors
The MC-8 will detect parity, framing and data overrun errors. If any of the physical layer errors are detected, the
complete packet is corrupted and the MC-8 will reset the transaction and begin to look for a start of packet byte.
4.4 MC-8 Receive Buffer
The MC-8 has an internal receive buffer. The buffer is 256 Bytes and will transmit a NAK packet with an error code
of DC_ERR_BUFFER_FULL to the HOST if the buffer is full. If the buffer is full, all data transmitted to the MC-8
will be ignored. Therefore, making the currently transmitted packet, if partially transmitted invalid.
4.5 MC-8 Hardware Verification
This test verifies the RS232 ports are working by comparing the transmitted signal (at pin 2) to the received signal
(at pin 3). The MC-8 transmits a known test signal just following a power up. The MC-8 monitors the serial port
receivers while transmitting the test signal. If the signals are the same, the test passes. In order to test this circuit,
RS232 Wraparound plug(s) are needed and must be installed at the female D9 connector(s) on the rear panel of the
MC-8 labeled “RS232”. The wraparound plug shorts pins 2 to 3, allowing for the MC-8 to receive the signal it is
transmitting. Once installed, power cycle the MC-8 and verify the following message is displayed on the FPD:
SERIAL PORT A PASSED
SERIAL PORT B PASSED
This message is displayed for about 2 seconds before entering normal operating mode. If no messages are displayed,
then both wrap tests failed.
MC-8
COM1
Transmit Data
Receive Data
Ground
Host
Receive Data
Transmit Data
Ground
2
3
5
2
3
5
9 Pin D-Shell (female) 9 Pin D-Shell (male)
2
3
5
2
3
5
9 Pin D-Shell (male)
9 Pin D-Shell (female)

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5 Data Link Layer
The data link layer is used to define a transmission packet. The layer appends a header and tail that encloses the
transmitted application packet data. The data link header will contain the start of packet byte and count of bytes to
follow. The data link tail will contain the end of packet byte.
5.1 Errors
If the number of DLL data bytes received is the same as the data count and an EOP has not been received, the MC-8
responds by transmitting a NAK packet with an error code DC_ERR_INVALID_PACKET. The MC-8 then
continues to look for a SOP byte and will not process the erroneous application packet. The HOST can use this as an
indicator to retransmit the corrupted packet.
In addition, each byte of a packet must be received sequentially and within the INTER_PACKET_TIME. If any of
the bytes within a packet transmission exceeds the INTER_PACKET_TIME, the MC-8 will respond by transmitting
a NAK packet with an error code DC_ERR_INVALID_PACKET. The MC-8 then continues to look for a SOP byte
and will not process the erroneous application packet. The HOST can use this as an indicator to retransmit the
corrupted packet.
6 Application Layer
6.1 MC-8 Asynchronous Notification Packets
MC-8 has been designed to transmit the asynchronous notification packets following these system changes:
1. Power On
2. Entering Standby
3. Front Panel Display update
4. Parameter Value Changes.
Data Link Header:
Byte Number Description Value
First Byte(0) Start of Packet (SOP) 0xF1
Byte(1) DLL Data Count nn
Application Header:
Byte(2) Command nn
Byte(3)
APP Data Count (number of application data bytes to
Follow) nn
Application Data:
Byte(4) Data[0] nn
Byte(5) Data[1] nn
… Data[…] nn
Last Data Byte -1 Data[Data Count -1] nn
Data Link Tail:
Last Byte End of Packet (EOP) 0xF2

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The notification packets are defined as follows:
6.1.1 Wakeup Notification
By transmitting the Wakeup Notification, MC-8 indicates the unit has just “powered on” or reset and is ready to
receive host commands. This notification is primarily for the HOST to know the status of the MC-8.
6.1.1.1 Notification Packet Description
Application Header:
Command DC_WAKEUP 0x01
Data Count 0 0x00
Application Data:
N/A
6.1.1.2 Host Response
The MC-8 does not expect any response from the HOST.
6.1.2 Sleep Notification
By transmitting the Sleep Notification, MC-8 indicates the unit is shutting down into a standby mode. Because the
hard power switch could be activated independently of the MC-8 system software, hard power down will not be
notified. Acknowledgment of the Sleep Notification is not required. This notification is primarily for the HOST to
know the operating status of the MC-8.
6.1.2.1 Notification Packet Description
Application Header:
Command DC_SLEEP 0x02
Data Count 0 0x00
Application Data:
N/A
6.1.3 Front Panel Display
MC-8 will transmit the front panel display buffer following the update to the MC-8 front panel display. The MC-8
front panel display is 2 X 20 ASCII character display. The HOST can enable transmission of this notification
message by sending Host Wakeup (7.3.29). To disable transmission the HOST can send Host Sleep (7.3.30).
Transmission of the display buffer is asynchronous to other host/MC-8 communication and will only transmit
following the completion of any communication exchanges in progress or pending.
6.1.3.1 Notification Packet Description
Application Header:
Command DC_FPD 0x03
Data Count 42 0x2A
Application Data:
Data[0] - Data[20] Line1 ch ch ch… 0x00
Data[21] - Data[41] Line2 ch ch ch … 0x00
6.1.3.2 Data Description

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Line1
Data Type: Null (0x00) terminated ASCII character string.
Max Length: DISP_LINE_LENGTH defined in Appendix G Protocol Constants.
Line2
Data Type: Null (0x00) terminated ASCII character string.
Max Length: DISP_LINE_LENGTH defined in Appendix G Protocol Constants.
The MC-8 includes 8 custom characters that are defined to display increments of a display block. (i.e. Volume Bar)
The custom characters are ASCII character codes 8E - 93(hex). The codes are used as follows:
'8E' - empty cell
'8F' - left 1 bar
'90' - left 2 bars
'91' - left 3 bars
'92' - left 4 bars
'93' - full cell
6.1.3.3 HOST Response
The MC-8 does not expect any response from the HOST.
6.1.4 MC-1 Parameter Change
MC-8 will transmit predetermined parameter change notifications. If a parameter value is changed due to any user
action or system action the MC-8 will transmit the current value of the parameter that is changing.
This command has been maintained for backward compatibility with MC-1. In order to maintain backward
compatibility, the MC-8 Parameters have been mapped to the MC-1 parameters as described in the Supported
System Parameters table listed below.
MC1 Parameter Change Notification can be enabled/disabled by using the Communication Configuration Packet as
described in 6.3.19 Get Communication Configuration and 6.3.20 Set Communication Configuration
The MC8 disables these notifications in its default state.
6.1.4.1 Notification Packet Description
Application Header:
Command DC_PARAM_CHG_MSG 0x04
Data Count 2 0x02
Application Data:
Data[0] ParamId nn
Data[1] Value nn
6.1.4.2 Data Description
ParamId:
Data Type: Unsigned 8 bit integer
Max: 255.
Value:
The Current Value for this system parameter.
Data Type: Unsigned 8 bit integer
Max: Set by the Max Value per the Parameter Definition response Packet for the
Parameter Id of this packet.