Lightware MODEX-OPTM-RX, User Manual

Page: 65 / 113

MODEX-OPTS, MODEX-OPTM
User’s Manual
Section 7.
Programmer’s reference
Page 65 / 113
7.
Programmer’s reference
7.1. LW3 protocol
– Overview
Lightware 3 (LW3) protocol is currently used by MODEX extender family, 25G product line
and will be the preferred protocol in new developments.
LW3 is an ASCII based protocol and all commands are terminated with a carriage return
(Cr,
‘\r’) and line feed (Lf, ‘\n’) pair. It is organized as a tree structure that provides
outstanding flexibility for implementing a human readable, but still easy to programmatically
parse protocol, which is suitable for different products with different feature list.
The concept
In order to implement a flexible, easy-to-use protocol that is straightforward to adapt to new
devices and provides outstanding scalability and sustainability, Lightware decided to
organize all settings, parameters and properties of the device to a tree structure with
‘nodes’, ‘properties’ and ‘methods’.
7.1.1. Elements of tree structure
Info: All names and values are case sensitive. Space character is replaced by
‘●’ character in
elements and commands descriptions.
Node

Basic building block of the tree structure is the
‘node’.

A 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.

Nodes are separated by a slash (
‘/’) character; no backslash is used.

The identifier of the root node is a slash (
‘/’).
 Nodes’ name can contain elements of the English alphabet and numbers.

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’: manual for the node (see section
7.2.9 on page 74 ),
‘E’:
error message for the node (see section 7.1.3 on page 68 ).
Info: All parent nodes must be listed in the path of a node.