/// <summary>
/// Read value from an OPC tag.
/// </summary>
/// <returns>Tag value.</returns>
public object ReadTagVal(string tagName)
{
if (String.IsNullOrEmpty(tagName))
{
throw new Exception(String.Format("OPC tag name '{0}' is not valid", tagName));
}
object tagValue = String.Empty;
if (!_server.IsConnected)
{
throw new Exception("Not connected to OPC server");
}
Item[] itemCollection = new Item[1];
itemCollection[0] = new Item {
ItemName = tagName, MaxAge = -1
};
ItemValueResult[] results = _server.Read(itemCollection);
if (results.Length > 0)
{
tagValue = results[0].Value;
}
return(tagValue);
}
