# Matlab OPC Ua ignition problem

**URL:** <https://forum.inductiveautomation.com/t/matlab-opc-ua-ignition-problem/90102>\
**Category:** Ignition\
**Created:** [May 8, 2024, 2:20pm UTC](https://forum.inductiveautomation.com/t/matlab-opc-ua-ignition-problem/90102 "2024-05-08T14:20:51Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![Jakub\_Zwolinski](https://avatars.discourse-cdn.com/v4/letter/j/3be4f8/32.png) [@Jakub\_Zwolinski](https://forum.inductiveautomation.com/u/Jakub_Zwolinski)\
**Post date:** [May 8, 2024, 2:20pm UTC](https://forum.inductiveautomation.com/t/matlab-opc-ua-ignition-problem/90102/1 "2024-05-08T14:20:51Z")

</div>

I have a strange problem / issue  
All the OPC Ua browser i used show me only two possible ways of using my node ids  
1 - '[PLC]UDT\_ACV\_V1001.S\_POS'  
2 - '1:Devices.[PLC].Controller&:Global.UDT\_ACV\_V1001.S\_POS'

But matlab can't directly acccess it..

In theory it should work like this

```python
% Create OPC UA client object
 uaClient = opcua("opc.tcp://localhost:62541");
% Connect the client to the OPC UA server
connect(uaClient);
nodeId = "ns=1;s=[PLC]UDT_ACV_V1001.LGC_CLS";
value = readValue(uaClient, nodeId );
disp(value);
disconnect(uaClient);

```

But this is not working...  
Instead what I need to do is 3 times find by name..

```python
DB_Node = findNodeByName(uaClient.Namespace, 'Devices', '-once'); 
ValvePointer = findNodeByName(DB_Node, 'UDT_ACV_V1001', '-once');
node = findNodeByName(ValvePointer, 'LS_CLS', '-once');
disp(node);
disconnect(uaClient);

```

But it really slows down the performance..  
Assuming that i will have to read thousands of signals.. Crazy enough!

Is there a way to make Ignition not to use brackets?  
i suspect it to be a problem with [PLC]  
if it would be PLC. - probably it would work

---

<div class="post-metadata">

**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\
**Post date:** [May 8, 2024, 2:30pm UTC](https://forum.inductiveautomation.com/t/matlab-opc-ua-ignition-problem/90102/2 "2024-05-08T14:30:55Z")

</div>

> [@Jakub\_Zwolinski](#):
>
> `ns=1;s=[PLC]UDT_ACV_V1001.LGC_CLS`

This is a NodeId.

> [@Jakub\_Zwolinski](#):
>
> '1:Devices.[PLC].Controller&:Global.UDT\_ACV\_V1001.S\_POS'

This looks like what is called a "BrowsePath" in OPC UA. It's different than a NodeId. I don't know what your client is doing with this, but if I had to guess it's just calling the TranslateBrowsePaths service to turn it into a NodeId before it reads anyway.

You should contact Matlab for support about why the NodeId doesn't work directly.