# \[BUG\] Inherited UDT parameter does not change when parameter has changed on parent UDT

**URL:** <https://forum.inductiveautomation.com/t/bug-inherited-udt-parameter-does-not-change-when-parameter-has-changed-on-parent-udt/55761>\
**Category:** Ignition\
**Tags:** ignition81\
**Created:** [February 4, 2022, 3:34pm UTC](https://forum.inductiveautomation.com/t/bug-inherited-udt-parameter-does-not-change-when-parameter-has-changed-on-parent-udt/55761 "2022-02-04T15:34:37Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![louagejasper](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/louagejasper/32/86311_2.png) [@louagejasper](https://forum.inductiveautomation.com/u/louagejasper)\
**Post date:** [February 4, 2022, 3:34pm UTC](https://forum.inductiveautomation.com/t/bug-inherited-udt-parameter-does-not-change-when-parameter-has-changed-on-parent-udt/55761/1 "2022-02-04T15:34:37Z")

</div>

Hi,

On 8.1.13.  
I have 2 UDT’s, 1 Parent UDT with 1 parameter and a Child UDT with no parameters.  
 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/2/d/2d100d8b76e2be575ee772c9073acf8313761133.png)

I would expect all child udt’s to inherit the parameter of the parent udt. When the parameter on the parent udt changes, I think it should be normal behavior for same thing to happen on the child UDT’s.

So to reproduces we have the following steps:

1. Add parent udt as parent.  
Both parameters are the same  
 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/8/e/8e395e4cf976708755cdc9c0688842de676a1205.png) ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/d/4/d4074469122f7cd65be28e9e8d08a2581b8339ee.png)

2. Change parameter on parent udt

3. Observe: child udt’s still have the same parameter as before.

![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/f/3/f3b6bbe84003aa6fe41171d5e9af69ebce31705c.png)  
 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/d/4/d4074469122f7cd65be28e9e8d08a2581b8339ee.png)

Should these parameters not change automatically if the parameter is not overwritten?

This is the exported json:

```auto
{
  "tags": [
    {
      "name": "udtPARENT",
      "parameters": {
        "OPCServer": {
          "dataType": "String",
          "value": "Server_new"
        }
      },
      "tagType": "UdtType"
    },
    {
      "name": "udtCHILD",
      "typeId": "udtPARENT",
      "parameters": {
        "OPCServer": {
          "dataType": "String",
          "value": "Server_old"
        }
      },
      "tagType": "UdtType"
    }
  ]
}

```

Jasper

---

<div class="post-metadata">

**Author:** ![kvane](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kvane/32/22228_2.png) [@kvane](https://forum.inductiveautomation.com/u/kvane)\
**Post date:** [February 7, 2022, 8:59pm UTC](https://forum.inductiveautomation.com/t/bug-inherited-udt-parameter-does-not-change-when-parameter-has-changed-on-parent-udt/55761/2 "2022-02-07T20:59:38Z")

</div>

I tested out your replication steps on version 8.1.14 and I do not see the behavior you described. The child UDT updated as expected:

Child UDT has the new parameter after only updating the Parent definition:  
 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/3/1/318dc29ba271a00538903efb44aa22990ba0f65c.png)

The JSON export does not show the parameter for the Child UDT (because it is default):

```auto
{
  "tags": [
    {
      "name": "udtPARENT",
      "parameters": {
        "OPCServer": {
          "dataType": "String",
          "value": "Server_new"
        }
      },
      "tagType": "UdtType"
    },
    {
      "name": "udtCHILD",
      "typeId": "udtPARENT",
      "tagType": "UdtType"
    }
  ]
}

```

Based on the JSON export it seems like your child instance may be identifying its Parameter as non-default/overwritten. This may be behavior that has been changed in 8.1.14, so upgrading to test may be useful. If you can replicate the issue easily on your system you could also reach out to our [support department](https://inductiveautomation.com/support/home/) and they can help confirm this.

---

<div class="post-metadata">

**Author:** ![louagejasper](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/louagejasper/32/86311_2.png) [@louagejasper](https://forum.inductiveautomation.com/u/louagejasper)\
**Post date:** [February 8, 2022, 7:34am UTC](https://forum.inductiveautomation.com/t/bug-inherited-udt-parameter-does-not-change-when-parameter-has-changed-on-parent-udt/55761/3 "2022-02-08T07:34:47Z")

</div>

Thanks kvane,

The issue is not easy to replicate, 80% of the times it does go well. I have created a support ticket with our actual data, where the issue always happens.  
We will upgrade to 8.1.14 and see if all issues are resolved, it does look like it has set the parameter to overwritten, but without showing the green circle for overwritten. Thanks.

Jasper