Echelon OpenLDV - Manual (Page 84)

76 Sending and Receiving Messages with the OpenLDV API
Message Code Comments
Set Node Mode 0x6C On-line and off-line only. OpenLDV application should send
corresponding immediate command (niONLINE or
niOFFLINE) to the network interface.
Wink 0x70 OpenLDV application should indicate receipt of message to user,
or handles a request to manage its self-documentation data.
Query SI 0x72 OpenLDV application should respond with self-identification and
self-documentation data.
NV Fetch 0x73 OpenLDV application should respond with network variable
data.
Using the Network Interface Command Interface
The following sections describe the OpenLDV command interface.
Downlink Commands
A downlink command is a message sent to a network interface from an OpenLDV
application with the ldv_write() function:
• The OpenLDV application sends application messages, network
management and diagnostics messages, network variable updates, and
network variable poll requests on the network through the network
interface using the niCOMM network interface command.
• The OpenLDV application also sends messages to the OpenLDV interface
that it generates in response to uplink request messages, including
responses to uplink network variable poll messages.
• The OpenLDV application sends messages to the OpenLDV interface in
response to certain uplink network management messages that it
receives for processing.
There are two categories of downlink communication:
• Immediate commands do not require an application output buffer in the
network interface, and are used to control the operation of the network
interface itself. Immediate commands are sent with all queue selection
bits cleared.
• Local network management commands are used to configure and control
the Smart Transceiver or Neuron Chip that is part of the network
interface. They are sent with the niNETMGMT network interface
command, and are not sent on the L ON W ORKS network.
Commands for Layer 5 devices that can be used with a specified queue include
niCOMM for messages sent to the network, and niNETMGMT for local network
management operation messages sent to the network interface. Local network
management messages use the Layer 5 buffer structure, regardless of which
layer the network interface uses for network messages.