Network variable syntax, Keywords, The network variable modifier – Echelon LonTal Stack User Manual

Page 176

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Appendix C: Appendix C


Neuron C Syntax for the

Model File

network output SNVT_amp nvoAmpere;
network output polled SNVT_time_stamp nvoInstallDate;

fblock SFPTopenLoopSensor {

nvoAmpere implements nvoValue;

nvoInstallDate

implementation_specific(128)

nvoInstall;
} fbAmpereMeter external_name("AmpereMeter")
fb_properties

{

cpDefaultOutput,

//

optional

CP

cpDisplayBrightness = {50.0, 1} // impl-specific

};

Network Variable Syntax

The syntax for declaring a single network variable object is:
network input | output [ netvar-modifier ] [ storage-class ] type
[

connection-info ] identifier

[

=

initial-value ] [ nv-property-list ] ;

The syntax for declaring an array of network variables is:

network input | output [ netvar-modifier ] [ storage-class ] type
[

connection-info ] identifier [ array-bound ]

[

=

initializer-list ] [ nv-property-list ] ;

The brackets around array-bound are shown in bold type. The brackets do not,

in this case, indicate an optional field. They are a required part of the syntax for
declaring an array, and must be entered into the program code.
Network variable arrays can only be single dimension. The array-bound must be
a constant. Each element of the array is treated as a separate network variable

for purposes of events, transmissions on the network, and so on. Therefore, each

element counts individually towards the maximum number of network variables
on a given device. Each element of the array is a separately bindable network

variable.

Keywords

network

Declares a network variable of a specific type and with a specific identifier.

input | output

Defines the direction (input or output) for the network variable, from the

point of view of the Echelon Smart Transceiver or Neuron Chip.

The Network Variable Modifier

The optional netvar-modifier specification for a network variable includes the
following keywords:

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