User`s guide

i.LON SmartServer 2.0 Programming Tools User’s Guide 219
v.GetDpPropertyAsString(Dp::cfgUCPTname),
v.GetDpPropertyAsString(Dp::cfgUCPTaliasName),
v.GetUCPTindex(),
v.GetDpPropertyAsItemCfgDepth(Dp::cfgItemDepth));
}
Notes:
• You can also define an xSelect statement that queries data point properties instead of actual data
points. For example, you could define an xSelect statement that queries the AliasName
configuration property of a data point.
char szXSelect[128] =
//Item[@xsi:type=\"Device_Cfg\"][UCPTaliasName=\"xxo\"]";
• If you define a more general xSelect statement that could return a set of mixed network objects
(e.g., devices, functional blocks, and data points), you need to evaluate the cfgItemDepth
property of the objects being returned. This property can have one of the following types:
ItemCfgDepth_Network // item is a network
ItemCfgDepth_Channel // item is a channel
ItemCfgDepth_Device // item is a device
ItemCfgDepth_Fb // item is a functional block
ItemCfgDepth_Dp // item is a data point
ItemCfgDepth_Cp // item is a configuration property
ItemCfgDepth_UNKNOWN // item has an unknown object type
• You can use the GetUCPTindex()in the List()method to obtain the network variable index
of the data point within its device.
Read()
You can perform a Read() method in an FPM application to read the values of the data points
returned by the List() method.
SYNTAX
STATUS Read(const CFpmItemInfo& rMeta,
Byte* const pbyValue,
unsigned int nSize,
bool bReadProperties = false,
int nMaxAgeMillis = -1);
In the CFpmItemInfo parameter, you must specify an object obtained by the List() method.
The object’s cfgItemDepth property must be of type ItemCfgDepth_Fb or
ItemCfgDepth_Dp; otherwise, this method returns an ERROR in the STATUS value.
The pbyValue parameter specifies the variable used to store the value returned by the method.
If a container is provided (pbyValue != NULL), this method returns the following properties
of the data points in addition to their values (if bReadProperties is set to true):
FPM::Dp::cfgUCPTname
FPM::Dp::dataUCPTlastUpdate
FPM::Dp::dataUCPTstatus
FPM::Dp::dataUCPTpriority
The nSize parameter specifies the size of the data point returned by the method.
The nMaxAgeMillis parameter specifies how the source of the data point value and how often
the FPM application polls the data point. This parameter accepts the following values: