# Type conversion error = squishy spot on forehead

**URL:** <https://forum.inductiveautomation.com/t/type-conversion-error-squishy-spot-on-forehead/7672>\
**Category:** Ignition\
**Created:** [December 5, 2013, 11:16pm UTC](https://forum.inductiveautomation.com/t/type-conversion-error-squishy-spot-on-forehead/7672 "2013-12-05T23:16:06Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![tpenke63](https://avatars.discourse-cdn.com/v4/letter/t/5fc32e/32.png) [@tpenke63](https://forum.inductiveautomation.com/u/tpenke63)\
**Post date:** [December 5, 2013, 11:16pm UTC](https://forum.inductiveautomation.com/t/type-conversion-error-squishy-spot-on-forehead/7672/1 "2013-12-05T23:16:06Z")

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OK… this one is just killing me… and the answer is probably ‘DOH’ simple:

Trying to multiply two UDT tag values to get a result.

UDT  
----- Tag1 (expression tag) (float8) – has a working expression  
----- Tag2 (expression tag) (float8) – will be a user input value  
----- Tag3 (expression tag) (float8) – the result

Tag3 expression:

toFloat({[~]UDT/Tag1}) \* toFloat({[~]UDT/Tag2})

I’ve tried other versions using tag(toFloat( and tag(

Anyone have any ideas?  
Thanks!

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<div class="post-metadata">

**Author:** ![Colby.Clegg](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/colby.clegg/32/3282_2.png) [@Colby.Clegg](https://forum.inductiveautomation.com/u/Colby.Clegg)\
**Post date:** [December 11, 2013, 9:35pm UTC](https://forum.inductiveautomation.com/t/type-conversion-error-squishy-spot-on-forehead/7672/2 "2013-12-11T21:35:39Z")

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Hi,

I think those references are simply incorrect. If all three tags are side by side like you describe, try:

```auto
{[.]Tag1}*{[.]Tag2}
```

When you use [~], it’s going to the root of the tag provider, which I doubt is what you want. It didn’t give you that through a tag selector, did it? If so, what version are you using?

Otherwise, perhaps you could export the udt in question, and I could try to import it.

Regards,

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<div class="post-metadata">

**Author:** ![tpenke63](https://avatars.discourse-cdn.com/v4/letter/t/5fc32e/32.png) [@tpenke63](https://forum.inductiveautomation.com/u/tpenke63)\
**Post date:** [December 14, 2013, 4:48pm UTC](https://forum.inductiveautomation.com/t/type-conversion-error-squishy-spot-on-forehead/7672/3 "2013-12-14T16:48:09Z")

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> [@](#):
>
> When you use [~], it's going to the root of the tag provider, which I doubt is what you want. It didn't give you that through a tag selector, did it? If so, what version are you using?

Yep... in the tag selector for an expression tag that is within a UDT. Version=7.6.4.2013112117 in an active production environment.

This only happens if I try to do any manipulation using tags within a UDT as such (this is an expression in UDT/Tag6):

```auto
({[~]UDT/Tag1}+{[~]UDT/Tag2}+{[~]UDT/Tag3}+{[~]UDT/Tag4}+{[~]UDT/Tag5})/5
```

Perhaps I am trying to do something outside of the scope of Ignition. Note that the above does work if I throw it into an expression for a numeric field value.

Meanwhile... I'm reading through documentation. Thanks!