//======================================================================
// GetStatus
/// <summary>
/// Returns the current server status.
/// </summary>
/// <returns>The current server status.</returns>
public ServerStatus GetStatus()
{
lock (this)
{
if (m_proxy == null)
{
throw new NotConnectedException();
}
OpcXml.Da10.RequestOptions options = OpcXml.Da10.Request.GetRequestOptions(m_options.Locale, m_options.Filters);
OpcXml.Da10.ServerStatus remoteStatus = null;
OpcXml.Da10.ReplyBase reply = m_proxy.GetStatus(
options.LocaleID,
options.ClientRequestHandle,
out remoteStatus);
CacheResponse(m_options.Locale, reply, null);
// fill in the last update time.
ServerStatus status = OpcXml.Da10.Request.GetServerStatus(reply, remoteStatus);
status.LastUpdateTime = m_lastUpdateTime;
return(status);
}
}
/// <summary>
/// Causes the server to send a data changed notification for all active items.
/// </summary>
/// <param name="requestHandle">An identifier for the request assigned by the caller.</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>
public virtual void Refresh(
object requestHandle,
out IRequest request)
{
lock (this)
{
request = null;
// do nothing is subscription is no longer valid.
if (m_state.ServerHandle == null)
{
return;
}
// begin the polled refresh.
OpcXml.Da10.RequestOptions options = OpcXml.Da10.Request.GetRequestOptions(m_state.Locale, m_filters);
// send a polled refresh that requests all items.
m_proxy.BeginSubscriptionPolledRefresh(
options,
new string [] { (string)m_state.ServerHandle },
m_server.ServerTime,
true,
0,
true,
new AsyncCallback(OnPollCompleted),
new string[] { (string)m_state.ServerHandle, options.LocaleID, null });
}
}
//======================================================================
// Write
/// <summary>
/// Writes the value, quality and timestamp for a set of items.
/// </summary>
/// <param name="items">The set of item values to write.</param>
/// <returns>The results of the write operation for each item.</returns>
public IdentifiedResult[] Write(ItemValue[] items)
{
if (items == null)
{
throw new ArgumentNullException("items");
}
if (items.Length == 0)
{
return(new Opc.IdentifiedResult[0]);
}
lock (this)
{
if (m_proxy == null)
{
throw new NotConnectedException();
}
ItemValueList list = new ItemValueList();
list.AddRange(items);
OpcXml.Da10.RequestOptions options = OpcXml.Da10.Request.GetRequestOptions(m_options.Locale, m_options.Filters);
OpcXml.Da10.WriteRequestItemList requestList = OpcXml.Da10.Request.GetItemValueList(list);
OpcXml.Da10.ReplyItemList replyList = null;
OpcXml.Da10.OPCError[] errors = null;
OpcXml.Da10.ReplyBase reply = m_proxy.Write(
options,
requestList,
false,
out replyList,
out errors);
CacheResponse(m_options.Locale, reply, errors);
ItemValueResultList valueList = OpcXml.Da10.Request.GetResultList(replyList);
if (valueList == null)
{
throw new InvalidResponseException();
}
IdentifiedResult[] results = new IdentifiedResult[valueList.Count];
for (int ii = 0; ii < valueList.Count; ii++)
{
ItemValueResult valueResult = valueList[ii];
results[ii] = new IdentifiedResult(valueResult);
results[ii].ResultID = valueResult.ResultID;
results[ii].DiagnosticInfo = valueResult.DiagnosticInfo;
}
return(results);
}
}
//======================================================================
// Read
/// <summary>
/// Reads the current values for a set of items.
/// </summary>
/// <param name="items">The set of items to read.</param>
/// <returns>The results of the read operation for each item.</returns>
public Opc.Da.ItemValueResult[] Read(Item[] items)
{
if (items == null)
{
throw new ArgumentNullException("items");
}
if (items.Length == 0)
{
return(new Opc.Da.ItemValueResult[0]);
}
lock (this)
{
if (m_proxy == null)
{
throw new NotConnectedException();
}
ItemList list = new ItemList();
list.AddRange(items);
OpcXml.Da10.RequestOptions options = OpcXml.Da10.Request.GetRequestOptions(m_options.Locale, m_options.Filters);
OpcXml.Da10.ReadRequestItemList requestList = OpcXml.Da10.Request.GetItemList(list);
OpcXml.Da10.ReplyItemList replyList = null;
OpcXml.Da10.OPCError[] errors = null;
OpcXml.Da10.ReplyBase reply = m_proxy.Read(
options,
requestList,
out replyList,
out errors);
CacheResponse(m_options.Locale, reply, errors);
ItemValueResultList valueList = OpcXml.Da10.Request.GetResultList(replyList);
if (valueList == null)
{
throw new InvalidResponseException();
}
return((ItemValueResult[])valueList.ToArray(typeof(ItemValueResult)));
}
}
/// <summary>
/// Starts polling for the current subscription.
/// </summary>
private void Poll(object state)
{
lock (this)
{
// do nothing is subscription is no longer valid.
if (m_state.ServerHandle == null)
{
return;
}
TimeSpan holdTime = TimeSpan.Zero;
TimeSpan waitTime = TimeSpan.Zero;
// use simple client side polling if not enabled.
if (m_enabled)
{
// hold time is the ping rate and the wait time is zero.
if (m_pingRate < m_state.UpdateRate)
{
holdTime = new TimeSpan(m_pingRate * 10000);
waitTime = TimeSpan.Zero;
}
// hold time is the update rate and the wait time is ping rate minus the update rate.
else
{
holdTime = new TimeSpan(m_state.UpdateRate * 10000);
waitTime = new TimeSpan((m_pingRate - m_state.UpdateRate) * 10000);
}
}
// begin the polled refresh.
OpcXml.Da10.RequestOptions options = OpcXml.Da10.Request.GetRequestOptions(m_state.Locale, m_filters);
m_proxy.BeginSubscriptionPolledRefresh(
options,
new string [] { (string)m_state.ServerHandle },
m_server.ServerTime.Add(holdTime),
true,
(int)waitTime.TotalMilliseconds,
false,
new AsyncCallback(OnPollCompleted),
new string[] { (string)m_state.ServerHandle, options.LocaleID, "" });
}
}
//======================================================================
// GetProperties
/// <summary>
/// Returns the item properties for a set of items.
/// </summary>
/// <param name="itemIDs">A list of item identifiers.</param>
/// <param name="propertyIDs">A list of properties to fetch for each item.</param>
/// <param name="returnValues">Whether the property values should be returned with the properties.</param>
/// <returns>A list of properties for each item.</returns>
public ItemPropertyCollection[] GetProperties(
ItemIdentifier[] itemIDs,
PropertyID[] propertyIDs,
bool returnValues)
{
if (itemIDs == null)
{
throw new ArgumentNullException("itemIDs");
}
if (m_proxy == null)
{
throw new NotConnectedException();
}
lock (this)
{
OpcXml.Da10.RequestOptions options = OpcXml.Da10.Request.GetRequestOptions(m_options.Locale, m_options.Filters);
OpcXml.Da10.PropertyReplyList[] properties = null;
OpcXml.Da10.OPCError[] errors = null;
OpcXml.Da10.ReplyBase reply = m_proxy.GetProperties(
OpcXml.Da10.Request.GetItemIdentifiers(itemIDs),
OpcXml.Da10.Request.GetPropertyNames(propertyIDs),
options.LocaleID,
options.ClientRequestHandle,
null,
(propertyIDs == null),
returnValues,
options.ReturnErrorText,
out properties,
out errors);
CacheResponse(options.LocaleID, reply, errors);
return(OpcXml.Da10.Request.GetItemPropertyCollections(properties));
}
}
/// <summary>
/// Establishes a subscription for the current set of items.
/// </summary>
private ItemValueResultList Subscribe(ArrayList items)
{
lock (this)
{
// cancel any current subscription.
Unsubscribe();
// check if there is nothing to do.
if (items == null || items.Count == 0)
{
return(new ItemValueResultList());
}
// create a single item list and use the subscription state to set list level parameters.
ItemList itemList = new ItemList();
itemList.ClientHandle = Guid.NewGuid().ToString();
itemList.ItemPath = null;
itemList.ReqType = null;
itemList.Deadband = m_state.Deadband;
itemList.DeadbandSpecified = true;
itemList.SamplingRate = m_state.UpdateRate;
itemList.SamplingRateSpecified = true;
itemList.EnableBuffering = false;
itemList.EnableBufferingSpecified = false;
// set the ping rate based on the keep alive (if specified) or five times update rate.
m_pingRate = (m_state.KeepAlive != 0)?m_state.KeepAlive:m_state.UpdateRate * 5;
// stop any existing timer.
if (m_pollTimer != null)
{
m_pollTimer.Dispose();
m_pollTimer = null;
}
// create copies of each and replace the client handle with the server handle.
foreach (Item item in items)
{
Item clone = (Item)item.Clone();
clone.ClientHandle = clone.ServerHandle;
itemList.Add(clone);
}
string subscription = null;
// establish the subscription on the server.
OpcXml.Da10.RequestOptions options = OpcXml.Da10.Request.GetRequestOptions(m_state.Locale, m_filters);
OpcXml.Da10.SubscribeReplyItemList replyList = null;
OpcXml.Da10.OPCError[] errors = null;
OpcXml.Da10.ReplyBase reply = m_proxy.Subscribe(
options,
OpcXml.Da10.Request.GetSubscribeList(itemList),
true,
m_pingRate * 2,
out replyList,
out errors,
out subscription);
// cache results with the server object.
m_server.CacheResponse(m_state.Locale, reply, errors);
// save subscription handle.
m_state.ServerHandle = subscription;
// check for valid response.
if (replyList == null)
{
throw new InvalidResponseException();
}
// save the revised update rate.
if (replyList.RevisedSamplingRateSpecified)
{
m_state.UpdateRate = (int)replyList.RevisedSamplingRate;
}
// update items.
ItemValueResultList resultList = OpcXml.Da10.Request.GetSubscribeResultList(replyList);
for (int ii = 0; ii < itemList.Count; ii++)
{
SubscribeItemValueResult resultItem = (SubscribeItemValueResult)resultList[ii];
// restore the client/server handles in the result.
resultItem.ServerHandle = resultItem.ClientHandle;
resultItem.ClientHandle = ((Item)items[ii]).ClientHandle;
// check if the requested sampling rate was accepted.
if (!resultItem.SamplingRateSpecified)
{
resultItem.SamplingRate = itemList[ii].SamplingRate;
resultItem.SamplingRateSpecified = itemList[ii].SamplingRateSpecified;
}
}
// schedule polling.
SchedulePoll();
// return result list.
return(resultList);
}
}
