type definitions and enums

[JeffOverton]

---

Ben wrote:

---

JeffOverton wrote:

I don't know about 8.6, but in 8 through 8.5 the constant will update when you change the typedef.

edit - Specifically if you add options to the enum, the constant will update to allow those new options to be selectable.

Message Edited by JeffOverton on 09-04-2008 10:53 AM

---

... but after the update the value it was set too will be retained as long as that value is still present. When I say "value" I'm refering to the string that was selected. Even if the enum is re-ordered such that the numeric value associated with the string is different, it should still have the same stirng selected.

Agreed?

Ben

---

Oh, I agree with that, yes.  The specific value of that specific constant instance of the type def will remain the same unless it's deleted from the type def.  I was speaking more in terms of enumerating states for a state machine, and if you add a state to the typedef, you can just right click the case structure and "add case for all values" because the constant will autoupdate as well.

[ShotSimon]

In enum1.vi I changed the enumerated type defined control to a constant and saved.  In Control 1.ctl, I added an item and saved and then select apply changes.  The constant in enum1.vi doesn't update? -SS 

[RavensFan]

I see what you mean. But there is one complication in your example.  You do not have an Enum.  You have a ring control.

I'm not sure if the behavior being shown is expected or not, but I know that there are some differences between enums and ring controls.  In enums, the name of a value is an integral part of the control.  In rings, the value is the key item, the name used in the display is more of a "decoration" and is not a critical part of the definition.

That is why if a control's names needed to be changed during runtime, it is required to use a ring rather than an enum.

[JeffOverton]

---

Ravens Fan wrote:

In rings, the value is the key item, the name used in the display is more of a "decoration" and is not a critical part of the definition.

That is why if a control's names needed to be changed during runtime, it is required to use a ring rather than an enum.

---

I believe that is expected behavior, because of the following:  Wire a ring to a case structure and wire an enum to a case structure, and the selectors will be completely different.  Additionally, the terminal of a ring control  even says U16, while an enum is just the left and right arrows.

[ShotSimon]

Yes sorry I was using a ring instead of enum.  But when I change everything to enum my constant doesn't update as I was expecting.  I saw this happen the first time but not after that.  -SS

[JeffOverton]

The first time, as in you changed the typedef, opened your VI (and the constant was changed), then changed your typedef again and the constant didn't change?  Is "Auto-Update from Type Def." checked?  Is your typedef strict?

[RavensFan]

Try this.

Go to your Ring constant.  Right click change to control.  Right click change to constant.

I don't know why, but that seemed to update the control to the saved type def. which persisted when it changed back to a constant.

It isn't automatic and in the background, but it did do the update in a few mouse clicks.

[RavensFan]

I replaced the ring constant with an enum constant.  The values from the ring did not automatically transfer over, so I had to edit the enum constant to add all the items.  I then made it a strict type def and saved it.

After that, I opened the control.vi and edited and deleted items, then saved it.  I didn't see any problems with the enum constant being updated automatically when I edited the strict type def control.

[ShotSimon]

JeffOverton, Yes "Auto-Update from Type Def." is checked and typedef is strict.

Ravens Fan, Yes your work around will work with ring controls but I was trying to avoid this.

The problem went away since I was accidentally not applying changes from the ctl file, this is important

Thanks guys for your help, I'm still learning the in's and out's of this useful feature.  -SS

Message Edited by ShotSimon on 09-04-2008 03:28 PM

[JeffOverton]

---

ShotSimon wrote:

The problem went away since I was accidentally not applying changes from the ctl file, this is important

---

haha, that'll do it

also, if you save the changes (but don't apply them) and then close the .ctl it will automatically apply the changes