Echelon Neuron C - Manual (Page 31)

Neuron C Reference Guide 11
array, the nv_array_index built-in variable indicates the relative index of the
element to which the event applies. The nv_array_index variable’s type is a short
int.
If a network variable range is used, then the network variable at the beginning of
the range must have a lower global index than the network variable at the end of
the range. Each network variable in the range is checked for failure until the
first such network variable with an event is found. The event occurs for each
network variable in the range that experiences a failure event.
Checking the completion event (nv_update_completes, or nv_update_fails in
combination with nv_update_succeeds) is optional by network variable.
If a program checks for the nv_update_succeeds event, it must check for the
nv_update_fails event as well. The alternative is to check only for
nv_update_completes. A program is also permitted to check only for
nv_update_fails as long as there is no use of nv_update_completes or
nv_update_succeeds for any network variable.
Syntax
nv_update_fails [( network-var )]
nv_update_fails [( network-var1 .. network-var2 )]
network-var A network variable identifier, a network variable array
identifier, or a network variable array element. A range
can be specified with two network variable identifiers or
network variable array elements separated with a range
operator (two consecutive dots). The range is defined by
the indices of the referenced network variables. If the
parameter is omitted, the event is TRUE when any
network variable update fails.
Example 1 – Event for a Single Network
Variable
network output SVNT_abs_humid nvoHumidity;
...
nvoHumidity = 32;
...
when (nv_update_fails(nvoHumidity))
{
...
}
Example 2 – Event for a Network Variable
Array
network output SVNT_abs_humid nvoHumidity[4];
...
nvoHumidity[1] = 32;