Session.Read() is taking very long

[Ragnar]

Hi,

I'm trying to read about 100 nodes from an OPC Server on the same machine using Session.Read(). Sadly, each of these reads takes up more than 10 seconds.
I'm relatively inexperienced when it comes to working with OPC Servers or networking in general, so maybe I'm overlooking some essential settings?

Code: Select all

for(int i = 0; i < 100; i++)
{
//creating about 100 nodes from a datasheet
     nodesToRead.Add(new ReadValueId() { NodeId = nodeId, AttributeId = Attributes.Value });
}

Code: Select all

while (true)
{
                dtn = DateTime.Now;
                List<DataValue> results = session.Read(nodesToRead,1,TimestampsToReturn.Both, new RequestSettings() { OperationTimeout = 100000 });
                Console.WriteLine(results.Count() + " items Read " + (DateTime.Now - dtn));
}

I do get the expected values, however every read takes 10-12 seconds to complete.

[Support Team]

Hi Ragnar,

The server returns very slow. This is not an issue on client side.

Note: the server returns the ReadResponse after it has collected all values. So if there is one "slow" value (e.g. the server has to wait for answer of an underlying system), the whole ReadResponse will be slow.