WMK_PROT_HISTORY_ITEM_DATA Struct Reference

Public Attributes
WMK_OPCPIPE_HANDLE	AppTopicHandle
	app topic handle (call pipe -> app; server side only)
WMK_OPCPIPE_HANDLE	PipeTopicHandle
	pipe topic handle (call app -> pipe; server side only)
WMK_OPCPIPE_HANDLE	AppItemHandle
	app item handle (call pipe -> app)
WMK_OPCPIPE_HANDLE	PipeItemHandle
	pipe item handle (call app -> pipe)
opcpipe_timeval	StartTime
	start time for history read (requests only)
opcpipe_timeval	EndTime
	end time for history read (requests only)
W_UINT32	ValueCount
	max. number of values to be read (requests only)
W_UINT32	Flags
	Bits for WMK_PROT_HISTORY_ITEM_DATA::Flags (requests only)
W_UINT32	Aggregate
	Values for WMK_PROT_HISTORY_ITEM_DATA::Aggregate (requests only)
double	AggregationInterval
W_UINT32	unused [2]
	currently unused, must be 0
W_UINT32	Quality
	item quality, Quality values, conforming to OPC (responses only)
W_UINT32	DataLen
	Number of data values present (write request, read response)
WMK_PROT_RW_ITEM_DATA *	Data
	data values (write request, read response)

Detailed Description

API Struct for reading historical data

Notes:

• At least 2 of StartTime, EndTime, ValueCount must be given.
• Use 0 for an unused value.
• If StartTime > EndTime, or StartTime is 0, values are returned in reverse order.

Member Data Documentation

AggregationInterval

double WMK_PROT_HISTORY_ITEM_DATA::AggregationInterval

aggregation interval, given in seconds (requests only) note that the TANI historian supports only some specific intervals 0 to ask for aggregation over the entire interval StartTime .. EndTime