MARK LEVINSON No53 Serial Protocol User Guide
- June 16, 2024
- Mark Levinson
Table of Contents
- MARK LEVINSON No53 Serial Protocol
- Product Information
- Product Usage Instructions
- FCC Notice
- Definitions, Acronyms, and Abbreviations
- General Description
- Ethernet Port & Cable Configuration
- Message Formats and Examples
- RQST Error Responses and Examples
- External Protocol Commands
- Critical Fault Notifications
- Notification Factory Defaults
- References
- Read User Manual Online (PDF format)
- Download This Manual (PDF format)
MARK LEVINSON No53 Serial Protocol
Product Information
Specifications
- Serial Protocol: No53 No532 Serial Protocol
- Trademark: Mark Levinson
- Manufacturer: Harman International Industries, Incorporated
- Part Number: 070-18998| Rev 1 |10/08
Product Usage Instructions
General Description
The No5 Series Amplifiers Serial Communications Protocol is designed for
communication between the Mark Levinson amplifier product and the HOST device.
It allows for control and interaction with the amplifier through serial
communication packets.
Ethernet Port & Cable Configuration
The amplifier can be connected to the HOST device using Ethernet cables. The
physical connection involves connecting one end of the Ethernet cable to the
Ethernet port of the amplifier and the other end to the Ethernet port of the
HOST device.
Physical Connection using Ethernet Cables
- Connect one end of the Ethernet cable to the Ethernet port of the amplifier.
- Connect the other end of the Ethernet cable to the Ethernet port of the HOST device.
Message Formats and Examples
The communication between the amplifier and the HOST device is done using
message formats. The message fields have specific formats for incoming
messages, outgoing messages, requests, responses, and notifications. Examples
of these message formats are provided below.
Format of the Message Fields
The message fields in the communication protocol have specific formats. These
formats are used to define the structure of the messages exchanged between the
amplifier and the HOST device.
Incoming Messages
Incoming messages are messages received by the amplifier from the HOST device.
These messages contain commands, parameters, or other instructions that the
amplifier needs to process.
Outgoing Messages
Outgoing messages are messages sent by the amplifier to the HOST device. These
messages include responses, notifications, or other information requested by
the HOST device.
-
Example Request – RQST
An example of a request message format is provided below:
RQST:CMD=PARAM,PARAM_VALUE -
Example Response – RSP
An example of a response message format is provided below:
RSP:ACK=PARAM,PARAM_VALUE -
Example Notification – NTF
An example of a notification message format is provided below:
NTF: AV=PARAM,PARAM_VALUE
RQST Error Responses and Examples
When an error occurs in processing a request message, the amplifier sends an
error response back to the HOST device. These error responses provide
information about the error that occurred.
External Protocol Commands
The No5 Series Amplifiers Serial Communications Protocol supports various
external protocol commands that can be used to control and interact with the
amplifier. Some of these commands are:
-
FAULT
The FAULT command is used to check the fault status of the amplifier. -
NOP
The NOP command is a no-operation command used for testing purposes. -
HWSTATUS
The HWSTATUS command is used to retrieve the hardware status of the amplifier. -
PWR
The PWR command is used to control the power state of the amplifier. -
TEMP
The TEMP command is used to retrieve the temperature status of the amplifier.
Critical Fault Notifications
Critical fault notifications are sent by the amplifier to the HOST device when
critical faults occur. These notifications provide information about the fault
that occurred.
Notification Factory Defaults
The amplifier supports notification factory defaults, which allow the user to
restore the default settings for notifications.
FAQ
-
Q: What documents should be used with this document?
A: The following documents should also be used with this document to understand how this protocol can be used with the No5 Series Amplifiers:- 070-18285 No53 Reference Monaural Power Amplifier Owner’s Manual
- 070-18979 No532 Dual Monaural Power Amplifier Owner’s Manual
-
Q: Are there any changes in this document?
A: No changes have been made to this document.
FCC Notice
This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures:
- Reorient or relocate the receiving antenna.
- Increase the separation between the equipment and the receiver.
- Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.
- Consult the dealer or an experienced radio/TV technician for help.
Caution! Changes or modifications not expressly approved by the party
responsible for compliance could void the user’s authority to operate the
equipment.
Canada
This Class B digital apparatus complies with Canadian ICES-003. Cet appareil
numérique de la Classe B est conforme à la norme NMB-003 du Canada.
Documents
The following documents should also be used with this document to understand
how this protocol can be used with the No5 Series Amplifiers.
- 070-18285 No53 Reference Monaural Power Amplifier Owner’s Manual
- 070-18979 No532 Dual Monaural Power Amplifier Owner’s Manual
Change List
No changes have been made.
Definitions, Acronyms, and Abbreviations
- \r represents the ASCII new line control character (0x0D)
- : External Protocol String Field Separator
- , External Protocol String Field Parameter Separator for multiple parameters
- ACK Acknowledge
- AV Audio Video System generated response
- CMD Command
- CS Control Source
- EOP End of Packet
- HOST The device initiating or receiving the serial communication packets to/from the amplifier.
- ML Mark Levinson
- No5xx The Mark Levinson amplifier product receiving or transmits the serial communication packets to/from the HOST.
- NAK/NACK No Acknowledge
- NTF Notification
- PARAM Parameter
- RM Resource Manager
- RQST Request
- RSP Response
- SOP Start of Packet
- SPLUT Serial Protocol Lookup Table
- SPG Serial Protocol Guidelines
- UI User Interaction
- User Parameter A user-changeable variable that stores a specific value that describes an operating condition for the amplifier.
General Description
An external host controller can use the external protocol to control and monitor the operation of the No5 Series Power Amplifiers. The protocol consists of simple ASCII character set-based commands, which are passed to the amplifier as command packets via the Ethernet port. The amplifier will reply to command packets with an acknowledgment to signify that the command has been recognized and acted upon.
Ethernet Port & Cable Configuration
The No5 series power amplifiers are capable of obtaining a dynamically allocated IP address when connected to a DHCP server and the Network User Options are configured to use the DHCP server (default behavior). The DHCP setting can be modified via the internal Web page of the amplifier. Refer to the amplifier’s user manual for further instructions. The amplifier setup for Ethernet Control is defaulted to Auto-Negotiate and recommends the end point to also be configured for Auto-Negotiation. However, the amplifiers are capable of:
- 10/100 BaseT
- Half/Full-duplex
- flow control
- Pause control
Note: These parameters are NOT user-adjustable.
Physical Connection using Ethernet Cables
- If using a Direct-to-Ethernet capable Component, use a Crossover Ethernet Cable.
- If using a router or switch, use a straight-through Ethernet Cable.
Message Formats and Examples
The external protocol consists of a structured format string with specific fields used to indicate:
- Message type
- Source of the command
- Command
- Status/Parameter
Messages can be transmitted to (incoming) and received from (outgoing) the amplifier to facilitate system control via the Ethernet connection.
Format of the Message Fields
All incoming and outgoing messages must use the following format:
-
HDR:SRC:CMD: PARAM\r
Fields are separated by a colon “:” and messages are terminated with a ‘\r’ control character (0x0d).- All fields, commands and associated parameters are case-sensitive and must be entered as listed in the External Protocol Commands table. Do not insert spaces in message sequences, unless they are indicated in the table.
- Maximum message size is 60 characters, including the line ending ASCII control character ‘\r’ (0x0D).
- When an incoming or outgoing message uses more than one parameter, the individual parameters must be separated by commas.
-
HDR:SRC:CMD:PARAM1,PARAM2,PARAM3,…\r
When an incoming command requires multiple parameters per request (RQST), ALL parameters for the given command must be entered AND in the order presented in the External Protocol Commands table, as the descriptors are not utilized in the parameter field of the command/response string. The response message also follows these guidelines.
Incoming Messages
The Header Field (1st field) of every external protocol string indicates the
type of message contained within the transmitted string. All incoming messages
to the amplifier contain the string “RQST” in the header field. Any other
string in the header field indicates an outgoing message. The control source
that issued the Request (RQST) expects a reply within 500ms after receipt of
the string to indicate that the message was received. This response can be an
acknowledgement (ACK), the requested action if a data parameter was requested,
or a WAIT to indicate the system has received the command but needs additional
time to process the request.
NOTE: When an incoming request is received, the system acknowledges
receipt of the string within 500ms of receiving the incoming message.
Outgoing Messages
Outgoing Messages are generated to acknowledge an incoming request, to provide
requested information, or to inform of a system action occurring. As with an
incoming message, the Header field is used to indicate the type of message
contained within the string. Outgoing messages will be a response (RSP) to a
request or a system-generated notification (NTF) message.
-
RSP – Response to Command Request
An outgoing RSP will be generated as a result of an incoming RQST. In most cases the response is an acknowledgement (ACK) unless the request is a query “?”. In the case of a query, the RSP contains the requested parameter, rather than an ACK. -
NTF – Notification of System Action
An NTF is generated as the result of a system action occurring. When commands are issued to the system, they are placed in a queue in the order they are received. When the command is acted upon and the requested action has completed or occurred, a notification is generated within the system. If enabled, the notifications are sent if a user manually manipulates the front panel buttons or controls, presses IR keys on the remote control, issues an RQST via External Protocol to instruct the system to perform an action, or if a system fault is detected.
When an NTF event occurs, the source field indicates the source of the event:
- UI (user interaction)
- AV (component generated) fault
It’s important to note that Notifications are only sent to the Controller if
they are enabled. See the Notification Factory Defaults section of this
document for the factory default settings. See the External Protocol Commands
section in this document for more information.
Also, as commands are issued to change the state of a notification event
(enable it or disable it), the external protocol notification database is
updated to store this new state information, so that user configured
notification states are automatically restored when the amplifier is power
cycled. However, the user-configured states are reset to Factory Defaults at
any time that the factory default settings are restored.
Example Request – RQST
- RQST:CS:PWR: ON\r – incoming Request (RQST) from a Control Source (CS) commanding Power (PWR) ON.
- RQST:CS:PWR:?\r – incoming Request (RQST) from a Control Source (CS) querying the Power (PWR) state.
- RQST:CS:PWR: NTF?\r – incoming Request (RQST) from a Control Source (CS) querying the Power (PWR) Notification state.
Example Response – RSP
- RSP:CS:PWR: ACK\r – outgoing Response (RSP) generated from a Control Source request, indicating the command (PWR) is valid and the parameter supplied during the request is within the expected range, acknowledging (ACK) the request is being processed.
- RSP:CS:PWR: ON\r – outgoing Response (RSP) generated from a Control Source query request, indicating the command (PWR) current state is (ON).
- RSP:CS:PWR: EN\r – outgoing Response (RSP) generated from a Control Source notification state query request, indicating the command (PWR) notification is enabled (EN).
Example Notification – NTF
- NTF:UI:PWR: ON\r – outgoing Notification generated from a User Interaction (UI), indicating the command power (PWR) has turned ON.
NOTE: Notifications for a specific command must be enabled for system- generated messages.
RQST Error Responses and Examples
The External Protocol responds with the following message parameters when an
unexpected Incoming Request string is detected. If these responses are
received, please verify spelling, spacing and capitalization of all characters
of the failing field.
The format of the response message string indicates where the error has been
detected, as shown in the examples:
-
INVALID_SRC – The entered Source is not valid and is not recognized by the system.
Example: RSP: INVALID_SRC\r – received if sending RQST:Cs:PWR: ON\r -
INVALID_CMD – The entered Command is not valid and is not recognized by the system.
Example: RSP:CS: INVALID_CMD\r – received if sending RQST:CS:PWr: ON\r -
INVALID_PRM – The entered Parameter is not a valid parameter for the given command, or is out of the acceptable range for the command.
Example: RSP:CS:VOL:INVALID_PRM\r – received if sending RQST:CS:PWR:On\r -
INVALID_STR – The entered Request String is not formatted correctly and is not valid.
Example: RSP:CS:INVALID_STR\r – received if sending QST:CS:PWR:ON\r, or RQST:CSPWR:ON\r -
NACK – The incoming request is Not Acknowledged, indicating the system is in Standby and the request is being ignored.
Example: RSP:CS:PWR: NACK\r – received if sending RQST:CS:PWR: ON\r while the system is in Standby and the Link2 master is in Standby. -
WAIT/ERROR – If the system is unable to process a request (RQST) within 500mS, the external protocol automatically generates the WAIT response indicating the system needs additional time for processing. Up to 3 wait responses can occur before the system responds with ERROR, signifying it is unable to process the request. The typical response format is utilized, with the command field representing the name of the command that the system needs additional time to process.
Example:- RSP:CS:PWR: WAIT\r
- RSP:CS:PWR: WAIT\r
- RSP:CS:PWR: WAIT\r
- RSP:CS:PWR:ERROR\r
External Protocol Commands
The command examples under the field “Incoming Request” assumes the keywords
RQST:CS: precedes the command parameter indicated in the table, i.e.
RQST:CS:PWR:ON\r
The command examples under the field “Outgoing Response” must include the
keyword RSP:CS: preceding the response indicated in the table, i.e.
RSP:CS:PWR:ACK\r
DSPLY – This command only applicable to the No53 Amplifier
Command| Parameter| Function| Incoming Request|
Outgoing Response| Comment
---|---|---|---|---|---
DSPLY| SETFB| Sets Display to Full Brightness| DSPLY: SETFB\r| DSPLY:ACK\r|
| SET2| Sets Display Brightness to Setting 2| DSPLY: SET2\r| DSPLY:ACK\r|
| SET1| Sets Display Brightness to Setting 1| DSPLY: SET1\r| DSPLY:ACK\r|
| OFF| Turns Display OFF| DSPLY: OFF\r| DSPLY:ACK\r|
| ?| Request Current Display Setting| DSPLY:?\r| DSPLY:SETFB\r| Display set to
Full Brightness
| | | DSPLY:?\r| DSPLY: SET2\r| Display Brightness at Set level 2
| | | DSPLY:?\r| DSPLY: SET1\r| Display Brightness at Set level 1
| | | DSPLY:?\r| DSPLY: OFF\r| Display is OFF
| EN| Enables Notification| DSPLY:EN\r| DSPLY:ACK\r|
| DIS| Disables Notification| DSPLY:DIS\r| DSPLY:ACK\r|
| NTF?| Query Notification State| DSPLY:NTF?\r| DSPLY:EN\r| Notification is
Enabled
| | | DSPLY:NTF?\r| DSPLY:DIS\r| Notification is Disabled
| | | | DSPLY:NACK\r| Command is ignored because the system is in Standby
mode.
FAULT
Command| Parameter| Function| Incoming Request|
Outgoing Response| Comment
---|---|---|---|---|---
FAULT| THERM| A critical system fault has occurred| Not Available| | See the
section “Critical Fault Notifications” in this doc for more details on this
command notification
| PWR| | Not Available| |
| SIGNAL| | Not Available| |
| UNKNOWN| | Not Available| |
NOP
Command| Parameter| Function| Incoming Request|
Outgoing Response| Comment
---|---|---|---|---|---
NOP| NOP| No operation is performed| NOP:NOP\r| NOP:ACK\r| Used for testing
communication
HWSTATUS
Command| Parameter| Function| Incoming Request|
Outgoing Response| Comment
---|---|---|---|---|---
HWSTATUS| NAME| Display the assigned host name.| HWSTATUS:NAME\r| Example:
HWSTATUS:NO53_00005B\r| Response Only.
Outgoing response column lists typical examples.
| MAC| Display the MAC address.| HWSTATUS:MAC\r| Example:
HWSTATUS:AABBCCDDEEFF\r
| IP| Display the Internet Protocol (IP) address.| HWSTATUS:IP\r| Example:
HWSTATUS:192.168.10.10\r
| STATICIP| Display the static IP address.| HWSTATUS:STATICIP\r| Example:
HWSTATUS:192.168.50.3\r
| MASK| Displays the IP address of the subnet mask.| HWSTATUS:MASK\r| Example:
HWSTATUS:255.255.255.0\r
| DHCP| DHCP Status| HWSTATUS:DHCP\r| HWSTATUS:ENABLE\r HWSTATUS:DISABLE\r|
Response only.
| MLNETVER| Displays the ML Net version.| HWSTATUS:MLNETVER\r| Example:
HWSTATUS:v0.1.0\r| For Customer Service use.
PWR
Command| Parameter| Function| Incoming Request|
Outgoing Response| Comment
---|---|---|---|---|---
PWR| ON| Amp Powered ON from Standby| PWR:ON\r| PWR:ACK\r|
| STANDBY| Place Amp into Standby Mode| PWR:STANDBY\r| PWR:ACK\r|
| LP| Place Amp into Low Power Mode| PWR:LP\r| PWR:ACK\r|
| ?| Request Current PWR State| PWR:?\r| PWR:ON\r| System Powered ON
| | | PWR:?\r| PWR:STANDBY\r| System in Standby
| | | PWR:?\r| PWR:LP\r| System in Low Power
| EN| Enables Notification| PWR:EN\r| PWR:ACK\r|
| DIS| Disables Notification| PWR:DIS\r| PWR:ACK\r|
| NTF?| Query Notification State| PWR:NTF?\r| PWR:EN\r| Notification is
Enabled
| | | PWR:NTF?\r| PWR:DIS\r| Notification is Disabled
TEMP
Command| Parameter| Function| Incoming Request|
Outgoing Response| Comment
---|---|---|---|---|---
TEMP| ALL| Requests all available temperatures in the box| TEMP:ALL\r|
TEMP:ACK\r|
| BOX| Requests the overall ambient temperature inside the amplifier|
TEMP:BOX\r| TEMP:ACK\r|
Critical Fault Notifications
System Error | Fault | Message |
---|---|---|
Over Temp (Internal) | Amplifier is operating at excessive temperature. |
NTF:AV:FAULT:THERM\r
Power Fail Condition| Power failure due to over voltage, under voltage, or AC
line power is outside of the line frequency limits.| NTF:AV:FAULT:PWR\r
Signal Fault| Indicates to Controller that the Component has had a General
Signal Fault with ML Net or Link2 attached devices| NTF:AV:FAULT:SIGNAL\r
System Software| General signal fault due to excessive DC offset or excessive
output current.| NTF:AV:FAULT:UNKNOWN\r
Notification Factory Defaults
Command| Factory
Default Setting
| Notes
---|---|---
DSPLY| No|
NOP| N/A| Notification not available for this command
NTF| N/A| Notification not available for this command
PWR| YES|
Mark Levinson and the Mark Levinson logo are trademarks of Harman
International Industries, Incorporated, in the United States and/or other
countries. Microsoft and Windows are registered trademarks of Microsoft
Corporation in the United States and/or other countries. Other company and
product names may be trademarks of the respective companies with which they
are associated.
©2008 Harman International Industries, Incorporated. All rights reserved.
This document should not be construed as a commitment on the part of Harman
International Industries, Incorporated. The information it contains is subject
to change without notice. Harman International Industries, Incorporated
assumes no responsibility for errors that may appear within this document.
For customer service and product shipment information, refer to the
www.marklevinson.com Web site.