Echelon Neuron C - Manual (Page 102)

90 Using Configuration Properties to Configure Device Behavior
A Neuron C program can have multiple device property lists. These lists are
merged together by the Neuron C compiler to create one combined device
property list. However, you cannot have more than one configuration property of
any given SCPT or UCPT type that applies to the device.
If two separate modules specify a particular configuration property of the same
type in the device property lists, this situation causes a compilation error.
Example of incorrect CP conflict:
UCPTsomeDeviceCp cp_family cpSomeDeviceCp;
SCPTlocation cp_family cpLocation;
SCPTlocation cp_family cpPlacement;
device_properties {
cpSomeDeviceCp,
cpLocation,
cpPlacement // Conflicts with cpLocation
};
Network Variable Property Lists
A network variable property list declares instances of configuration properties
defined by CP family declarations and configuration network variable
declarations that apply to a network variable. See the Neuron C Reference Guide
for the configuration network variable’s property list syntax.
Example:
// CP for heartbeat and throttle (default 1 min each)
SCPTmaxSndT cp_family cpMaxSendT = { 0, 0, 1, 0, 0 };
SCPTminSndT cp_family cpMinSendT = { 0, 0, 1, 0, 0 };
// NV with heartbeat and throttle:
network output SNVT_lev_percent nvoValue
nv_properties
{
cpMaxSendT,
// override default for minSendT to 30 seconds:
cpMinSendT = { 0, 0, 0, 30, 0 }
};
The network variable property list begins with the nv_properties keyword. It
then contains a list of property references, separated by commas, exactly like the
device property list. Each property reference must be the name of a previously
declared CP family or the name of a previously declared configuration network
variable. The rest of the syntax is very similar to the device property list syntax
discussed above.
Following the
property-identifier , there can be an optional initializer , and an
optional range-mod . These optional elements are discussed in more detail in the
Neuron C Reference Guide .
You cannot have more than one configuration property of any given SCPT or
UCPT type that applies to the same network variable. A compilation error occurs
when a particular configuration property type is used for more than one property
in the network variable’s property list.
Unlike device properties, network variable properties can be shared between two
or more network variables. The use of the global keyword creates a CP family