Command Types; Prefix Summary; Error Messages; Escaping - Lightware VINX-110-HDMI-DEC User Manual

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5. Programmers' Reference
5.2.5. Command Aypes
GEA command
The GET command can be used to get the child nodes, properties and
methods of a specific node. It can also be used to get the value of a
property. Use the dot character (.) when addressing a property:
ç GET /.SerialNumber
æ pr /.SerialNumber=87654321
GEAALL command
The GETALL command can be used to get all child nodes, properties
and methods of a node with one command.
ç GETALL /MEDIA/UART
æ n- /MEDIA/VIDEO/I1
æ n- /MEDIA/VIDEO/O1
æ n- /MEDIA/VIDEO/QUALITY
æ pr /MEDIA/VIDEO.I1=I1
æ pr /MEDIA/VIDEO.O1=O1
æ pr /MEDIA/VIDEO.PortCount=2
SEA command
The SET command can be used to modify the value of a property. Use
the dot character (.) when addressing the property:
ç SET /MEDIA/VIDEO/QUALITY.QualityMode=0
æ pw /MEDIA/VIDEO/QUALITY.QualityMode=0
CALL command
A method can be invoked by the CALL command. Use the colon
character (:) when addressing the method:
ç CALL /MEDIA/VIDEO/QUALITY:applySettings(true)
æ mO /MEDIA/VIDEO/QUALITY:applySettings
VINX-1x0-HDMI Extenders – User's Manual

5.2.6. Prefix Summary

DEFINITION:
The prefix is a 2-character long code that describes
the type of the response.
The following prefixes are defined in the LW3 protocol:
Prefix Description
n- a node
nE an error for a node
nm a manual of a node
ns a child node of a node
pr a read-only property
pw read-write property
pE an error for the property
pm a manual for the property
m- a method
mO a response after a success method execution
mF a response after a failed method execution
mE an error for a method
mm a manual for a method

5.2.7. Error Messages

There are several error messages defined in the LW3 protocol, all of
them have a unique error number.
ç SET /MEDIA/UART/P1.Baudrate=9
æ pE /MEDIA/UART/P1.Baudrate %E004:Invalid value

5.2.8. Escaping

DEFINITION: An escape sequence is a sequence of characters that
does not represent itself when used inside a character or string
literal, but is translated into another character or a sequence of
characters.
Property values and method parameters can contain characters which
are used as control characters in the protocol. They must be escaped.
The escape character is the backslash ('\') and escaping means
injecting a backslash before the character that should be escaped
(like in C language).
Control characters are the followings: \ { } # % ( ) \r \n \t
The original message:
CALL /MEDIA/UART/P1:sendMessage(Set(01))
The escaped message:
CALL /MEDIA/UART/P1:sendMessage(Set\(01\))

5.2.9. Subscription

DEFINITION: Subscribe to a node means that the user will get a
notification if any of the properties of the node is changed.
A user can subscribe to any node. These notifications are asynchronous
messages and they are useful to keep the client application up to date,
without receiving any unwanted information. When the user does
not want to be informed about the changes anymore, he can simply
unsubscribe from the node.
AAAENAIING!
The subscriptions are handled separately for
connections. Hence, if the connection is terminated all registered
subscriptions are deleted. After closing a connection the subscribe
command has to be sent in order to get the notifications of the
changes on that connection.
Subscribe to a Node
ç OPEN /MEDIA/VIDEO
æ o- /MEDIA/VIDEO
Get the Active Subscriptions
ç OPEN
æ o- /MEDIA/VIDEO
æ o- /EDID
æ o- /DISCOVERY
Subscribe to Multiple Nodes
ç OPEN /MEDIA/VIDEO/*
æ o- /MEDIA/VIDEO/*
Unsubscribe from a Node
ç CLOSE /MEDIA/VIDEO
æ c- /MEDIA/VIDEO
Unsubscribe from Multiple Nodes
ç CLOSE /MEDIA/VIDEO/*
æ c- /MEDIA/VIDEO/*
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