Echelon OpenLDV User Manual download pdf (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

ONWORKS 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.

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Echelon OpenLDV User Manual Page 84