Read modified data from an OPC HDA server
DObj = readModified(HdaClient,ItmList,StartTime,EndTime)
DObj = readModified(HdaClient,ItmList,StartTime,EndTime) reads
modified data from the items defined by
stored on the OPC HDA server connected to OPC HDA Client
StartTime (inclusive) and
must be date numbers, or character vectors that can be converted to
a MATLAB date number.
DObj is returned as an
opc.hda.Data array, with
one element per item specified in
DObj contains only data items that have been
modified, replaced, or deleted on the OPC HDA server; that is, only
data values that return a quality of
'Extra Data' during
readRaw operation. If a value
has been modified multiple times, all values for that time are returned.
Some servers do not support this function.