internal void RefreshAllForPollingManager()
{
_cachedValues.Clear();
Tag lastHandledTag = null;
try
{
foreach (Tag tag in _tagsSnapshot)
{
if (!tag.IsActive)
{
continue;
}
lastHandledTag = tag;
object value;
if (ReadValueSynchronously(tag, out value))
{
_cachedValues.Add(tag, value);
}
}
}
catch (Exception e)
{
RaiseCommunicationProblem(e);
var exception = new PlcCommunicationException("Can't read tag " + lastHandledTag.FullName(), _adsAddress,
_adsPort.ToString(CultureInfo.InvariantCulture), string.Empty, e);
exception.Tag = lastHandledTag;
throw exception;
}
}
private bool IsAdsException(PlcCommunicationException exception)
{
var innerException = exception.InnerException;
while (innerException != null)
{
if (innerException is AdsErrorException)
{
return(true);
}
innerException = innerException.InnerException;
}
return(false);
}
/// <summary>
/// Reads the element from the specified <paramref name="elementPath"/> and returns it.
/// </summary>
/// <param name="elementPath">The path to read from.</param>
/// <param name="typeOfElement">The type of the desired element.</param>
/// <returns>The read value.</returns>
public object ReadElement(string elementPath, Type typeOfElement)
{
int handle = -1;
try
{
handle = _twinCatClient.CreateVariableHandle(elementPath);
return(_twinCatClient.ReadAny(handle, typeOfElement));
}
catch (AdsErrorException e)
{
var exception = new PlcCommunicationException("Can't read tag " + elementPath, _path,
_port.ToString(CultureInfo.InvariantCulture), string.Empty, e);
throw exception;
}
finally
{
if (handle != -1)
{
_twinCatClient.DeleteVariableHandle(handle);
}
}
}
private bool ReadValueSynchronously(Tag tag, out object newValue)
{
lock (_lock)
{
try
{
Connect();
}
catch (AdsErrorException e)
{
var exception = new PlcCommunicationException("Can't read tag synchronously. Connection to PLC failed.", _adsAddress,
_adsPort.ToString(CultureInfo.InvariantCulture), string.Empty, e);
exception.Tag = tag;
throw exception;
}
}
try
{
// try to read UDT
if (_udtHandler.ContainsKey(tag.DataType))
{
return(ReadUdt(tag, out newValue));
}
using (var dataStream = new AdsStream(tag.BitSize == 0 ? 81 : tag.BitSize / 8))
{
Address address = GetPlcAddress(tag);
try
{
if (address == null)
{
int handle = _twinCatClient.CreateVariableHandle(tag.FullName());
try
{
_twinCatClient.Read(handle, dataStream);
}
finally
{
_twinCatClient.DeleteVariableHandle(handle);
}
}
else
{
_twinCatClient.Read(address.IndexGroup, address.IndexOffset, dataStream);
}
}
catch (AdsErrorException ex)
{
_logger.Warn("Couldn't read " + tag.FullName() + " because " + ex.ErrorCode.ToString() + " will try again...");
// try again
try
{
if (address == null)
{
int handle = _twinCatClient.CreateVariableHandle(tag.FullName());
try
{
_twinCatClient.Read(handle, dataStream);
}
finally
{
_twinCatClient.DeleteVariableHandle(handle);
}
}
else
{
_twinCatClient.Read(address.IndexGroup, address.IndexOffset, dataStream);
}
_logger.Info("Second try for " + tag.FullName() + " was successful");
}
catch (AdsErrorException e)
{
var exception = new PlcCommunicationException("Can't read tag " + tag.FullName(), _adsAddress,
_adsPort.ToString(CultureInfo.InvariantCulture), string.Empty, e);
exception.Tag = tag;
throw exception;
}
}
newValue = ParseValueFromStream(tag, dataStream);
return(true);
}
}
catch (Exception e)
{
_logger.Warn(tag.FullName() + " value change leaded to a unhandled exception", e);
var exception = new PlcCommunicationException("Can't read tag " + tag.FullName(), _adsAddress,
_adsPort.ToString(CultureInfo.InvariantCulture), string.Empty, e);
exception.Tag = tag;
throw exception;
}
}
public void ReadTagSynchronously(Tag tag)
{
tag.LockValue();
try
{
lock (_lock)
{
if (!_twinCatClient.IsConnected)
{
try
{
_twinCatClient.Connect(_adsAddress, _adsPort);
_twinCatClient.Timeout = Timeout;
}
catch (AdsException e)
{
throw new PlcCommunicationException("Can't read tag synchronously. Connection to PLC failed.", _adsAddress,
_adsPort.ToString(CultureInfo.InvariantCulture), string.Empty, e);
}
}
}
// try to read UDT
if (_udtHandler.ContainsKey(tag.DataType))
{
ReadUdt(tag);
return;
}
var dataStream = new AdsStream(tag.BitSize == 0 ? 81 : tag.BitSize / 8);
try
{
int handle = _twinCatClient.CreateVariableHandle(tag.FullName());
try
{
_twinCatClient.Read(handle, dataStream);
}
finally
{
_twinCatClient.DeleteVariableHandle(handle);
}
}
catch (AdsErrorException e)
{
throw new PlcCommunicationException("Can't read tag " + tag.FullName(), _adsAddress,
_adsPort.ToString(CultureInfo.InvariantCulture), string.Empty, e);
}
ParseValueFromStream(tag, dataStream);
}
catch (Exception e)
{
if (_logger != null)
{
_logger.Warn(tag.FullName() + " value change leaded to a unhandled exception", e);
}
var exception = new PlcCommunicationException("Can't read tag " + tag.FullName(), _adsAddress,
_adsPort.ToString(CultureInfo.InvariantCulture), string.Empty, e);
exception.Tag = tag;
throw exception;
}
finally
{
tag.ReleaseValue();
}
}
