# Substitution Symbol vs Value **URL:** \ **Category:** Ignition\ **Tags:** ignition79\ **Created:** [February 9, 2021, 7:07pm UTC](https://forum.inductiveautomation.com/t/substitution-symbol-vs-value/43205 "2021-02-09T19:07:04Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![philippeg](https://avatars.discourse-cdn.com/v4/letter/p/e495f1/32.png) [@philippeg](https://forum.inductiveautomation.com/u/philippeg)\ **Post date:** [February 9, 2021, 7:07pm UTC](https://forum.inductiveautomation.com/t/substitution-symbol-vs-value/43205/1 "2021-02-09T19:07:04Z")
Version 7:9:16 Hello, thanks in advance for any insight or help…much appreciated We are converting a project from a other package (iFix) to Ignition. Without judging, just comparing, iFix has what GE calls TAG GROUP Basically it is an association between a SYMBOL and a VALUE The Symbol is what is bound to the animation on screen, while the value is the one being displayed. Obviously if you have multiple files using the same SYMBOL but different values, then it is possible to have a screen that would display values depending on which file you load For instance File 1 Node LOUISE PRODUCT APPLE VALUE 10 Were Node is the symbol and Louise the Value, same for product and apple and value and 10 File 2 Node TOM PRODUCT ORANGE VALUE 30 File 3 Node TOM PRODUCT LETUCE VALUE 40 If you display NODE TAG and VALUE On screen and you change the file then the screen will change from displaying LOUISE APPLE 10 to TOM LETUCE 40 This is pretty much similar to what UDT are in ignition except that iFIX is not loading TAGNAME (although it could) and it is based on files being read I could create a UDT for each files and a MEMORY TAG for each SYMBOL but with 50 files and 20 parameters each it would be 1000 memory tags just to do the substitution So what is the best way in Ignition 7.9.to do this type of substitution ? Is there an other way than UDT ? Thanks Regards Philippe Gras ---
**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:** [February 9, 2021, 9:22pm UTC](https://forum.inductiveautomation.com/t/substitution-symbol-vs-value/43205/2 "2021-02-09T21:22:34Z")
No need to use a UDT at all. Look at parameter passing in system.nav.openWindow. Where iFix is using a symbol, you use a Root Container Custom Property in Ignition. Another concept for similar behavior in Ignition is the use of a _tag path_ string with _indirect_ tag binding. All of this is basic Ignition technology that is best absorbed via [Inductive University](https://www.inductiveuniversity.com/library/). ---
**Author:** ![philippeg](https://avatars.discourse-cdn.com/v4/letter/p/e495f1/32.png) [@philippeg](https://forum.inductiveautomation.com/u/philippeg)\ **Post date:** [February 9, 2021, 9:37pm UTC](https://forum.inductiveautomation.com/t/substitution-symbol-vs-value/43205/3 "2021-02-09T21:37:29Z")
I see what you mean. I was over thinking …thanks ---
**Author:** ![nminchin](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/nminchin/32/6911_2.png) [@nminchin](https://forum.inductiveautomation.com/u/nminchin)\ **Post date:** [February 11, 2021, 11:47am UTC](https://forum.inductiveautomation.com/t/substitution-symbol-vs-value/43205/4 "2021-02-11T11:47:36Z")
Igntion is farr more powerful than iFix (and FactoryT for that matter - they use similar methods to iFix with their parameter files; awful things!) As Phil said, to make anything dynamic, just use custom properties / template parameters to pass a base tag path (to a popup or device template, or even a a Window, for example) , and then use indirect bindings that use the tag path and the rest of the path to the tag you want to bind to appended onto the end. The best thing is, you don’t have to create a million files in order to pass simple parameters to your things