Error browsing OPC using tunneller device via OPC-DA server

I have 10 PCs running windows xp with 7.8.2 (32-bit) installed. I’ve created an OPC-DA server on each machine referencing the Opto22OPCServer and associated tag database file, along with a tunneler device, both connected. I have created 10 individual OPC-UA servers on the primary gateway (also 7.8.2 on Windows Server 2008 R2 Standard, 64-bit), corresponding to each machine. All devices populate in Quick Client, as well as the OPC browser in designer. The tags are located in 3 distinct folders, 2 of which will successfully open and import to the tag browser. The third (and largest) file consistently times out with the following:

Error browsing OPC.
GatewayException: Results for asynchronous rpc call were not received within the specified amount of time [120000 ms] for task ‘1c3ed43a-cc88-42e2-9da0-214fcb6a48ab’
caused by TimeoutException: Results for asynchronous rpc call were not received within the specified amount of time [120000 ms] for task ‘1c3ed43a-cc88-42e2-9da0-214fcb6a48ab’

Ignition v7.8.2 (b2016030813)
Java: Oracle Corporation 1.8.0_101

I’ve attempted to increase the “Read Timeout” value in Project>Properties>Client>Timing>Read Timeout, but the default value was 60,000 ms and the error above references 120,000 ms and increasing this value resulted in identical behavior. Is there some other location I could increase the timeout value?

Additionally, 3 of the 10 devices will browse all tags successfully. Are there constraints related to the processing capacity of each tunneller host machine?

I should add that I did select the “Use DA2 when possible” checkbox and deselected “Use Async Operations” on the OPC-DA server settings to get to this point.

Let’s clarify your architecture first.
When you say you have “created an OPC-DA server on each machine referencing the Opto22OPCServer”, do you mean an OPC-DA Client connection from Ignition installed on your Windows XP box(es) to Opto22OPCServer (wherever it is installed)?

If so, can you browse the folder in question from the Quick Client on the Gateway that has the OPC-COM Client connection to the Opto22OPCServer that has those tags? Can you read any of those tags in the Quick Client on that Gateway? Subscribe to them? Keep in mind, that at this stage, we are NOT involving the Tunneller yet.

Try the above, let me know what the results are, and we will go from there.

Yes, the architecture you described is accurate, and the Opto22 software is on the same XP machine.

The Quick Client, as well as the OPC Browser in the designer, are able to browse all tags successfully on at least 2 of the 7 machines in question. Also, importing to the Tag Browser was successful.

The OPC Browser did require 2 minutes and 13 seconds to display all the tags in the folder I described previously. Do you think it’s as simple as increasing the 120000 ms referenced in the error I keep getting when browsing via the tunneller?

Does anyone have any more input on this? I’ve called tech support, but didn’t really solve anything.

Unfortunately there’s a couple parts of the system where this 2 minute timeout seems to be a hardcoded value rather than configurable. I’ll get a ticket going to make this settable somewhere in the future.

Kevin, not sure how I missed this, but will I be notified somehow when this is updated? Will it just be an updated version of the tunneller module?

It’s not as simple as an update to the tunneller module. The 2 minute timeout is hardcoded deep in the communication logic between client/designer and gateway. Making it configurable could have some wider reaching implications. I made a ticket for this a few weeks ago so it doesn’t get lost, but best case scenario would be that it gets implemented in Ignition 7.9.4.

Okay, thank you for the timely response.