# Kepserver Codesys driver, Ignition opc item path for dynamic tag access

**URL:** <https://forum.inductiveautomation.com/t/kepserver-codesys-driver-ignition-opc-item-path-for-dynamic-tag-access/63889>\
**Category:** Ignition\
**Tags:** ignition81\
**Created:** [September 8, 2022, 4:06pm UTC](https://forum.inductiveautomation.com/t/kepserver-codesys-driver-ignition-opc-item-path-for-dynamic-tag-access/63889 "2022-09-08T16:06:26Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![mazeyrat](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/mazeyrat/32/10955_2.png) [@mazeyrat](https://forum.inductiveautomation.com/u/mazeyrat)\
**Post date:** [September 8, 2022, 4:06pm UTC](https://forum.inductiveautomation.com/t/kepserver-codesys-driver-ignition-opc-item-path-for-dynamic-tag-access/63889/1 "2022-09-08T16:06:26Z")

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I try to read tag **not previously** created in kepserver with **codesys driver.**  
No sure it could be done with this driver.

**Ignition:**  
Data Type = Short  
OPC item Path  
nsu=KEPServerEX;s=Codesys.EC4P\_1.mot\_de\_vie  
or nsu=KEPServerEX;s=Codesys.EC4P\_1…mot\_de\_vie

**KepServer:**  
Provide the error:  
compatible with the device data type. | Tag address = ‘.mot\_de\_vie’, server data type = ‘String’, device data type = ‘.mot\_de\_vie’.

**Perhaps there is another item synthax in Ignition to provide the type ?**

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<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:** [September 8, 2022, 4:11pm UTC](https://forum.inductiveautomation.com/t/kepserver-codesys-driver-ignition-opc-item-path-for-dynamic-tag-access/63889/2 "2022-09-08T16:11:31Z")

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Ignition has absolutely nothing to do with this - whatever you put into the OPC Item Path is used as the NodeId, and it’s 100% up to the server how it interprets that NodeId or what the syntax is.

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<div class="post-metadata">

**Author:** ![mazeyrat](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/mazeyrat/32/10955_2.png) [@mazeyrat](https://forum.inductiveautomation.com/u/mazeyrat)\
**Post date:** [September 8, 2022, 5:10pm UTC](https://forum.inductiveautomation.com/t/kepserver-codesys-driver-ignition-opc-item-path-for-dynamic-tag-access/63889/3 "2022-09-08T17:10:09Z")

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Yes I see. The error message in the kep Doc mention that the item is wrong or the data type.  
In my case it must the item name requested not existing in kep opcua adresse space.  
I think that this driver doesn’t support creating item on the fly, and tag must be created in kep before. ☹

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<div class="post-metadata">

**Author:** ![mazeyrat](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/mazeyrat/32/10955_2.png) [@mazeyrat](https://forum.inductiveautomation.com/u/mazeyrat)\
**Post date:** [September 9, 2022, 7:13am UTC](https://forum.inductiveautomation.com/t/kepserver-codesys-driver-ignition-opc-item-path-for-dynamic-tag-access/63889/4 "2022-09-09T07:13:42Z")

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@Kevin.Herron,

It was finally a “datatype” issue in kepserver.

For **dynamic tag in Kepserver** , I need to specify the type at the end of the opc item path.  
In my use case:

```auto
nsu=KEPServerEX;s=Codesys.EC4P_1..mot_de_vie@Short

```

Dynamic tags are created on the fly by keyserver from the Ignitin opcua client request.  
For codesys driver the datatype of the tag need to be specified as it can’t be deducted from the opcitem name like it can be done with synthax in modbus or S7 driver.

 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/6/7/67e4046fd4d4e8a59124e9f976a8b27cc7f860b6.png)