/// <summary>
/// Invokes callback for a read request.
/// </summary>
private bool InvokeCallback(TsCHdaReadValuesCompleteEventHandler callback, object results)
{
// check for valid result type.
if (!typeof(TsCHdaItemValueCollection[]).IsInstanceOfType(results))
{
return(false);
}
TsCHdaItemValueCollection[] values = (TsCHdaItemValueCollection[])results;
// update item handles and actual times.
UpdateResults(values);
try
{
callback(this, values);
}
catch
{
// ignore exceptions in the callbacks.
}
// check if all data has been sent.
foreach (TsCHdaItemValueCollection value in values)
{
if (value.Result == OpcResult.Hda.S_MOREDATA)
{
return(false);
}
}
// request is complete.
return(true);
}
/// <summary>
/// Starts an asynchronous read values at specific times request for all items in the trend.
/// </summary>
public OpcItemResult[] ReadAtTime(
object requestHandle,
TsCHdaReadValuesCompleteEventHandler callback,
out IOpcRequest request)
{
return(ReadAtTime(GetItems(), requestHandle, callback, out request));
}
/// <summary>
/// Sends an asynchronous request to read item values that have been deleted or replaced.
/// </summary>
/// <param name="startTime">The beginning of the history period to read.</param>
/// <param name="endTime">The end of the history period to be read.</param>
/// <param name="maxValues">The number of values to be read for each item.</param>
/// <param name="items">The set of items to read (must include the item name).</param>
/// <param name="requestHandle">An identifier for the request assigned by the caller.</param>
/// <param name="callback">A delegate used to receive notifications when the request completes.</param>
/// <param name="request">An object that contains the state of the request (used to cancel the request).</param>
/// <returns>A set of results containing any errors encountered when the server validated the items.</returns>
internal OpcItemResult[] ReadModified(
TsCHdaTime startTime,
TsCHdaTime endTime,
int maxValues,
OpcItem[] items,
object requestHandle,
TsCHdaReadValuesCompleteEventHandler callback,
out IOpcRequest request)
{
if (_server == null)
{
throw new NotConnectedException();
}
OpcItemResult[] results = ((ITsCHdaServer)_server).ReadModified(
startTime,
endTime,
maxValues,
items,
requestHandle,
callback,
out request);
return(results);
}
/// <summary>
/// Sends an asynchronous request to read item values that have been deleted or replaced.
/// </summary>
/// <param name="startTime">The beginning of the history period to read.</param>
/// <param name="endTime">The end of the history period to be read.</param>
/// <param name="maxValues">The number of values to be read for each item.</param>
/// <param name="items">The set of items to read (must include the item name).</param>
/// <param name="requestHandle">An identifier for the request assigned by the caller.</param>
/// <param name="callback">A delegate used to receive notifications when the request completes.</param>
/// <param name="request">An object that contains the state of the request (used to cancel the request).</param>
/// <returns>A set of results containing any errors encountered when the server validated the items.</returns>
internal OpcItemResult[] ReadModified(
TsCHdaTime startTime,
TsCHdaTime endTime,
int maxValues,
OpcItem[] items,
object requestHandle,
TsCHdaReadValuesCompleteEventHandler callback,
out IOpcRequest request)
{
LicenseHandler.ValidateFeatures(LicenseHandler.ProductFeature.HistoricalAccess);
if (Server == null)
{
throw new NotConnectedException();
}
OpcItemResult[] results = ((ITsCHdaServer)Server).ReadModified(
startTime,
endTime,
maxValues,
items,
requestHandle,
callback,
out request);
return(results);
}
/// <summary>
/// Starts an asynchronous read values at specific times request for a set of items.
/// </summary>
public OpcItemResult[] ReadAtTime(
TsCHdaItem[] items,
object requestHandle,
TsCHdaReadValuesCompleteEventHandler callback,
out IOpcRequest request)
{
DateTime[] timestamps = new DateTime[Timestamps.Count];
for (int ii = 0; ii < Timestamps.Count; ii++)
{
timestamps[ii] = Timestamps[ii];
}
return(_server.ReadAtTime(timestamps, items, requestHandle, callback, out request));
}
/// <summary>
/// Sends an asynchronous request to read raw data from the historian database for a set of items.
/// </summary>
/// <param name="startTime">The beginning of the history period to read.</param>
/// <param name="endTime">The end of the history period to be read.</param>
/// <param name="maxValues">The number of values to be read for each item.</param>
/// <param name="includeBounds">Whether the bounding item values should be returned.</param>
/// <param name="items">The set of items to read (must include the item name).</param>
/// <param name="requestHandle">An identifier for the request assigned by the caller.</param>
/// <param name="callback">A delegate used to receive notifications when the request completes.</param>
/// <param name="request">An object that contains the state of the request (used to cancel the request).</param>
/// <returns>A set of results containing any errors encountered when the server validated the items.</returns>
internal OpcItemResult[] ReadRaw(
TsCHdaTime startTime,
TsCHdaTime endTime,
int maxValues,
bool includeBounds,
OpcItem[] items,
object requestHandle,
TsCHdaReadValuesCompleteEventHandler callback,
out IOpcRequest request)
{
if (_server == null)
{
throw new NotConnectedException();
}
return(((ITsCHdaServer)_server).ReadRaw(startTime, endTime, maxValues, includeBounds, items, requestHandle, callback, out request));
}
/// <summary>
/// Starts an asynchronous read modified request for a set of items.
/// </summary>
public OpcItemResult[] ReadModified(
TsCHdaItem[] items,
object requestHandle,
TsCHdaReadValuesCompleteEventHandler callback,
out IOpcRequest request)
{
OpcItemResult[] results = _server.ReadModified(
StartTime,
EndTime,
MaxValues,
items,
requestHandle,
callback,
out request);
return(results);
}
/// <summary>
/// Starts an asynchronous read request for a set of items.
/// </summary>
public OpcItemResult[] Read(
TsCHdaItem[] items,
object requestHandle,
TsCHdaReadValuesCompleteEventHandler callback,
out IOpcRequest request)
{
// read raw data.
if (Aggregate == TsCHdaAggregateID.NoAggregate)
{
return(ReadRaw(items, requestHandle, callback, out request));
}
// read processed data.
else
{
return(ReadProcessed(items, requestHandle, callback, out request));
}
}
/// <summary>
/// Starts an asynchronous read processed request for a set of items.
/// </summary>
public OpcItemResult[] ReadProcessed(
TsCHdaItem[] items,
object requestHandle,
TsCHdaReadValuesCompleteEventHandler callback,
out IOpcRequest request)
{
TsCHdaItem[] localItems = ApplyDefaultAggregate(items);
OpcItemResult[] results = _server.ReadProcessed(
StartTime,
EndTime,
ResampleInterval,
localItems,
requestHandle,
callback,
out request);
return(results);
}
/// <summary>
/// Sends an asynchronous request to read item values at specific times.
/// </summary>
/// <param name="timestamps">The set of timestamps to use when reading items values.</param>
/// <param name="items">The set of items to read (must include the item name).</param>
/// <param name="requestHandle">An identifier for the request assigned by the caller.</param>
/// <param name="callback">A delegate used to receive notifications when the request completes.</param>
/// <param name="request">An object that contains the state of the request (used to cancel the request).</param>
/// <returns>A set of results containing any errors encountered when the server validated the items.</returns>
internal OpcItemResult[] ReadAtTime(
DateTime[] timestamps,
OpcItem[] items,
object requestHandle,
TsCHdaReadValuesCompleteEventHandler callback,
out IOpcRequest request)
{
if (_server == null)
{
throw new NotConnectedException();
}
OpcItemResult[] results = ((ITsCHdaServer)_server).ReadAtTime(
timestamps,
items,
requestHandle,
callback,
out request);
return(results);
}
