Lw3 Programmers' Reference; Overview; Elements Of The Tree Structure - Lightware HDMI20-OPTC-TX220-Pro User Manual

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6. LW3 Programmers' Reference

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L W3 Programmers' Reference
The device can be controlled through Lightware 3 (LW3) protocol commands
to ensure the compatibility with other Lightware products. The supported LW3
commands are described in this chapter.

Overview

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The Tree Structure
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LW3 commands
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Formal Definitions
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System Commands
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Video Port and Crosspoint Settings
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Network Configuration
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RS-232 Port Configuration
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Sending Message via the Communication Ports
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EDID Management
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LW3 Commands - Quick Summary
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HDMI20-OPTC series – User's Manual
6.1. Overview
The Lightware 3 protocol (LW3) is an ASCII-based, tree-structured protocol that provides outstanding
flexibility. The protocol is easy to handle and programmatically still ease to parse, which is suitable for
different products with a different feature list.
All commands are terminated with a carriage return (Cr, '\r') and line feed (Lf, '\n') pair. In order to implement
a flexible, easy-to-use protocol that is straightforward to adapt to new devices and provides outstanding
scalability and sustainability, we decided to organize all settings, parameters and properties of the device to
a tree structure with nodes, properties, and methods.
6.1.1. Elements of the Tree Structure
ATTENTION! All names and values are case-sensitive. The space character is replaced by the '●' character
in the elements and commands descriptions.
6.1.1.1. Node
The basic building block of the tree structure is the 'node'.
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▪ The node can have multiple child nodes, but only one parent.
▪ The tree has only one root the 'root node'.
The leaves of the tree are also nodes, which do not have child nodes.
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The nodes are separated by a slash ('/') character.
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▪ All the slashes are 'right slashes', no backslash is used.
The identifier of the root node is a slash ('/')
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The node name can contain the elements of the English alphabet and numbers.
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▪ Recommended convention for case sensitivity:
– Fix nodes (that cannot be altered) are capitalized.
– User created nodes can contain both lowercase and capital letters, no restrictions.
▪ The path of a node has to contain all parent nodes from the root node.
Format: (the root node): nX●/
Path: nX●/[nodeName]/[nodeName]/[nodeName]
Legend:
n: node
'X' can be:
'-': default for a node.
'm': this is a manual for the node.
'E': this is an error message for the node.
's': this is a symlink node.
'v': this node has virtual children.
'r': this is a remote node.
INFO: All parent nodes must be listed in the path of a node.
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