/// <summary>
/// Removes the item from the group.
/// </summary>
/// <param name="item">The item.</param>
/// <returns>True if the item exists.</returns>
public bool RemoveItem(GroupItem item)
{
// add the item if it does not exist.
if (item == null)
{
return false;
}
// flag the item as deleted.
item.Deleted = true;
return true;
}
/// <summary>
/// Modifies the item.
/// </summary>
/// <param name="item">The item.</param>
/// <param name="samplingInterval">The sampling interval.</param>
/// <param name="deadband">The deadband.</param>
/// <param name="active">if set to <c>true</c> [active].</param>
/// <returns>True if the item is in the group.</returns>
public bool ModifyItem(GroupItem item, int samplingInterval, float deadband, bool active)
{
// check if the item can be added to the group.
if (m_samplingInterval != samplingInterval || m_deadband != deadband)
{
// check if the item needs to be removed from the group.
if (m_items.Count > 1)
{
item.Deleted = true;
return false;
}
// update active state.
item.ActiveChanged = active != item.Active;
item.Active = active;
// update the group parameters.
m_samplingInterval = samplingInterval;
m_deadband = deadband;
m_updateRequired = true;
return true;
}
// undelete the item.
item.Deleted = false;
// update active state.
item.ActiveChanged = active != item.Active;
item.Active = active;
// nothing to do - the group matches the item.
return true;
}
/// <summary>
/// Sets the monitored items associated with the item.
/// </summary>
/// <param name="item">The item.</param>
/// <param name="monitoredItems">The monitored items.</param>
public void SetMonitoredItems(GroupItem item, MonitoredItem[] monitoredItems)
{
// check if callbacks are enabled.
if (item == null || m_monitoredItems == null)
{
return;
}
// save the monitored items.
lock (m_monitoredItems)
{
DataChangeInfo info = null;
if (!m_monitoredItems.TryGetValue(item.ClientHandle, out info))
{
m_monitoredItems[item.ClientHandle] = info = new DataChangeInfo();
}
info.MonitoredItems = monitoredItems;
// resend the last cached value.
if (info.LastError != null || info.LastValue != null)
{
for (int ii = 0; ii < monitoredItems.Length; ii++)
{
monitoredItems[ii].QueueValue(info.LastValue, info.LastError);
}
}
}
}
/// <summary>
/// Creates the item.
/// </summary>
/// <param name="itemId">The item id.</param>
/// <param name="samplingInterval">The sampling interval.</param>
/// <param name="deadband">The deadband.</param>
/// <param name="active">if set to <c>true</c> [active].</param>
/// <returns>
/// The item that was added to the group. Null if the item could not be added.
/// </returns>
public GroupItem CreateItem(string itemId, int samplingInterval, float deadband, bool active)
{
// set the group parameters if this is the first item.
if (m_items.Count == 0)
{
m_samplingInterval = samplingInterval;
m_deadband = deadband;
}
// check if the item can be added to the group.
if (m_samplingInterval != samplingInterval || m_deadband != deadband)
{
return null;
}
// create the item.
GroupItem item = new GroupItem();
item.ItemId = itemId;
item.ClientHandle = Utils.IncrementIdentifier(ref m_itemCounter);
item.ServerHandle = 0;
item.Active = active;
item.ActiveChanged = false;
item.Deleted = false;
item.Created = false;
item.ErrorId = 0;
lock (Lock)
{
m_items.Add(item);
}
return item;
}
/// <summary>
/// Writes the item values to servers.
/// </summary>
/// <param name="requests">The requests.</param>
private void WriteItemValues(List <WriteRequest> requests)
{
ComDaGroup group = new ComDaGroup(this, false);
try
{
int count1 = 0;
GroupItem[] items = new GroupItem[requests.Count];
WriteRequest[] addItemRequests = new WriteRequest[requests.Count];
// create the items in the temporary group.
for (int ii = 0; ii < requests.Count; ii++)
{
WriteRequest request = requests[ii];
if (request == null)
{
continue;
}
// status code writes not supported.
if (request.Value.StatusCode != StatusCodes.Good)
{
request.Error = ResultIds.E_NOTSUPPORTED;
continue;
}
// timestamp writes not supported.
if (request.Value.SourceTimestamp != DateTime.MinValue)
{
request.Error = ResultIds.E_NOTSUPPORTED;
continue;
}
// add the item.
items[count1] = group.CreateItem(request.ItemId, 0, 0, true);
addItemRequests[count1] = request;
count1++;
}
// create the items on the server.
group.ApplyChanges();
// build the list of values to write.
int count2 = 0;
int[] serverHandles = new int[count1];
object[] values = new object[count1];
WriteRequest[] writeRequests = new WriteRequest[count1];
for (int ii = 0; ii < count1; ii++)
{
// check for error on create.
GroupItem item = items[ii];
WriteRequest request = addItemRequests[ii];
if (item.ErrorId < 0)
{
request.Error = item.ErrorId;
continue;
}
serverHandles[count2] = item.ServerHandle;
values[count2] = ComUtils.GetVARIANT(request.Value.Value);
writeRequests[count2] = request;
count2++;
}
// write values to the server.
int[] errors = group.SyncWrite(serverHandles, values, count2);
// read the errors.
for (int ii = 0; ii < count2; ii++)
{
writeRequests[ii].Error = errors[ii];
}
}
finally
{
// delete the group and items.
group.Delete();
}
}
