Echelon FTXL User Manual

Page 148

Advertising
background image

136

Neuron C Syntax for the Model File

network variables.
This keyword is not required for model files. Names of array elements are

automatically expanded by the LonTalk Interface Developer compiler.

offline

Specifies that a network management tool must take this device offline, or

ensure that the device is already offline, before updating the network
variable.
Do not use this feature in the bind_info for a configuration network variable

that is declared using the config_prop or cp keyword. Instead, use the offline
option in the cp_info.

unackd | unackd_rpt | ackd [ ( config | nonconfig ) ]

Selects the LonTalk protocol service to use for updating this network
variable. The allowed types are:
unackd — unacknowledged service; the update is sent once and no

acknowledgment is expected.
unackd_rpt — repeated service; the update is sent multiple times and no

acknowledgments are expected.
ackd (the default) — acknowledged service with retry; if acknowledgments

are not received from all receiving devices before the layer 4 retransmission

timer expires, the message is sent again, up to the retry count.
An unacknowledged (unackd) network variable uses minimal network
resources to propagate its values to other devices. As a result, propagation

failures are more likely to occur, and failures are not detected by the device.

This class might be used for variables that are updated on a frequent,
periodic basis, where loss of an update is not critical, or in cases where the

probability of a collision or transmission error is extremely low.
The repeated (unackd_rpt) service is typically used when a message is

propagated to many devices, and a reliable delivery is required. This service
reduces the network traffic caused by a large number of devices sending

acknowledgements simultaneously and can provide the same reliability as

the acknowledged service by using a repeat count equal to the retry count.
The config keyword indicates that this service type can be changed by a

network management tool. This option allows the tool to change the service

specification during installation. config is the default.
The nonconfig keyword indicates that this service cannot be changed by a

network management tool.

authenticated | nonauthenticated [ ( config | nonconfig ) ]

Specifies whether the network variable update requires authentication. With
authentication, the identity of the sending device is verified by all receiving

devices. Abbreviations for authenticated and nonauthenticated are auth and

nonauth.
The config keyword indicates that this service type can be changed by a

network management tool. This option allows the tool to change the service

specification during installation. config is the default
The nonconfig keyword indicates that this service cannot be changed by a

network management tool.

Advertising