# Change value of tag set by parameter **URL:** \ **Category:** Ignition\ **Created:** [July 31, 2020, 7:44pm UTC](https://forum.inductiveautomation.com/t/change-value-of-tag-set-by-parameter/37273 "2020-07-31T19:44:30Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![Jonathan](https://avatars.discourse-cdn.com/v4/letter/j/aeb1de/32.png) [@Jonathan](https://forum.inductiveautomation.com/u/Jonathan)\ **Post date:** [July 31, 2020, 7:44pm UTC](https://forum.inductiveautomation.com/t/change-value-of-tag-set-by-parameter/37273/1 "2020-07-31T19:44:30Z")
Why do I get this error when I try to change the value of a UDT tag that was set by the UDT’s parameters? My tags Access Rights are set to Read/Write. ```auto Error writing to script.value: Bad_ReadOnly("The specified value is dynamic and cannot be written.") ``` ---
**Author:** ![Kyle\_Chase](https://avatars.discourse-cdn.com/v4/letter/k/9de0a6/32.png) [@Kyle\_Chase](https://forum.inductiveautomation.com/u/Kyle_Chase)\ **Post date:** [July 31, 2020, 7:46pm UTC](https://forum.inductiveautomation.com/t/change-value-of-tag-set-by-parameter/37273/2 "2020-07-31T19:46:05Z")
What type of binding are you using? ---
**Author:** ![Jonathan](https://avatars.discourse-cdn.com/v4/letter/j/aeb1de/32.png) [@Jonathan](https://forum.inductiveautomation.com/u/Jonathan)\ **Post date:** [July 31, 2020, 7:47pm UTC](https://forum.inductiveautomation.com/t/change-value-of-tag-set-by-parameter/37273/3 "2020-07-31T19:47:38Z")
Value Source? It is Memory ---
**Author:** ![Jonathan](https://avatars.discourse-cdn.com/v4/letter/j/aeb1de/32.png) [@Jonathan](https://forum.inductiveautomation.com/u/Jonathan)\ **Post date:** [July 31, 2020, 8:08pm UTC](https://forum.inductiveautomation.com/t/change-value-of-tag-set-by-parameter/37273/4 "2020-07-31T20:08:59Z")
Is it because the memory tags value is bound to the parameter? ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/4/9/49910f0d5ba72f97728cc0df35b2946e0e35cb7f.png) Is there some other way I am suppose to set the tag to the parameter? ---
**Author:** ![BryanB](https://avatars.discourse-cdn.com/v4/letter/b/57b2e6/32.png) [@BryanB](https://forum.inductiveautomation.com/u/BryanB)\ **Post date:** [August 1, 2020, 12:56am UTC](https://forum.inductiveautomation.com/t/change-value-of-tag-set-by-parameter/37273/5 "2020-08-01T00:56:59Z")
Try using an expression tag instead. ---
**Author:** ![Jonathan](https://avatars.discourse-cdn.com/v4/letter/j/aeb1de/32.png) [@Jonathan](https://forum.inductiveautomation.com/u/Jonathan)\ **Post date:** [August 3, 2020, 3:35pm UTC](https://forum.inductiveautomation.com/t/change-value-of-tag-set-by-parameter/37273/6 "2020-08-03T15:35:45Z")
Changing to an expression tag has the same issue. I am running version 8.0.12. ---
**Author:** ![Jonathan](https://avatars.discourse-cdn.com/v4/letter/j/aeb1de/32.png) [@Jonathan](https://forum.inductiveautomation.com/u/Jonathan)\ **Post date:** [August 3, 2020, 4:35pm UTC](https://forum.inductiveautomation.com/t/change-value-of-tag-set-by-parameter/37273/7 "2020-08-03T16:35:18Z")
I just upgraded to 8.0.15 and I have the same issue. ---
**Author:** ![Kyle\_Chase](https://avatars.discourse-cdn.com/v4/letter/k/9de0a6/32.png) [@Kyle\_Chase](https://forum.inductiveautomation.com/u/Kyle_Chase)\ **Post date:** [August 3, 2020, 10:36pm UTC](https://forum.inductiveautomation.com/t/change-value-of-tag-set-by-parameter/37273/8 "2020-08-03T22:36:10Z")
You can not write to an expression tag or a bound property on a memory tag. You will want to try a derived tag instead. Giving us more info and maybe we can provide more help. ---
**Author:** ![Jonathan](https://avatars.discourse-cdn.com/v4/letter/j/aeb1de/32.png) [@Jonathan](https://forum.inductiveautomation.com/u/Jonathan)\ **Post date:** [August 4, 2020, 3:05pm UTC](https://forum.inductiveautomation.com/t/change-value-of-tag-set-by-parameter/37273/9 "2020-08-04T15:05:47Z")
I am trying to create a UDT instance with some of the tags inside the UDT being set to an initial value. If I cannot change the values later by writing to them that will not work. I can easily create the UDT instance and then immediately write to the UDT changing the values to there initial state. I just thought it would be better to create the UDT all in one statement than it would be to have to create the tag and then write the values in a second statement. ---
**Author:** ![Kyle\_Chase](https://avatars.discourse-cdn.com/v4/letter/k/9de0a6/32.png) [@Kyle\_Chase](https://forum.inductiveautomation.com/u/Kyle_Chase)\ **Post date:** [August 4, 2020, 4:16pm UTC](https://forum.inductiveautomation.com/t/change-value-of-tag-set-by-parameter/37273/10 "2020-08-04T16:16:36Z")
Are the initial values different for specific instances? If not, you can set the initial value in the udt. ---
**Author:** ![Jonathan](https://avatars.discourse-cdn.com/v4/letter/j/aeb1de/32.png) [@Jonathan](https://forum.inductiveautomation.com/u/Jonathan)\ **Post date:** [August 4, 2020, 4:21pm UTC](https://forum.inductiveautomation.com/t/change-value-of-tag-set-by-parameter/37273/11 "2020-08-04T16:21:28Z")
Yes every instance will have different initial values. ---
**Author:** ![drewdin](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/drewdin/32/3363_2.png) [@drewdin](https://forum.inductiveautomation.com/u/drewdin)\ **Post date:** [September 24, 2024, 9:40pm UTC](https://forum.inductiveautomation.com/t/change-value-of-tag-set-by-parameter/37273/12 "2024-09-24T21:40:49Z")
did you ever figure this out? ---
**Author:** ![michael.flagler](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/michael.flagler/32/26272_2.png) [@michael.flagler](https://forum.inductiveautomation.com/u/michael.flagler)\ **Post date:** [September 24, 2024, 9:59pm UTC](https://forum.inductiveautomation.com/t/change-value-of-tag-set-by-parameter/37273/13 "2024-09-24T21:59:53Z")
What are you trying to do? Looking back at this, it seems Ignition is doing what would be expected in that dynamic values that derive their value from an expression or binding will not allow you to write to them as it inherently is a read-only value at that point. ---
**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\ **Post date:** [September 24, 2024, 10:04pm UTC](https://forum.inductiveautomation.com/t/change-value-of-tag-set-by-parameter/37273/14 "2024-09-24T22:04:11Z")
My spreadsheet import tool on the exchange explicitly handles this case, and with careful iteration, can do so with very tight spreadsheet content.