6. LW3 Programmers’ Reference
HDMI20-OPTC series – User's Manual
37
LW3 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.
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’.
▪
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.
▪
The nodes are separated by a slash (‘/’) character.
▪
All the slashes are ‘right slashes’, no backslash is used.
▪
The identifier of the root node is a slash (‘/’)
▪
The node name can contain the elements of the English alphabet and numbers.
▪
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.
Ý
Ý
Ý
Ý
Ý
Ý
Video Port and Crosspoint Settings
Ý
Ý
Ý
Sending Message via the Communication Ports
Ý
Ý
