Calls sending the request for the current data. By calling this method all tvTrend objects that were successfully connected to the data sources (e.g. by calling the tvTrend.Connect method), send the request for the data to the connected servers.
Calling the method always calls the onReadData event. The tvTrend objects that are not connected to any data source (to a variable in the PmTrend object), can use the event for "manual" (i.e. in the script) filling of the buffer for viewer data.