How to get altitide data from in activity file to be usefull in the CIQ simulator?

Not clear what are you doing. Are you trying to replay a fit file in the simulator? If yes, then after loading it have you clicked the black Play button triangle in the bottom-left corner?

Stupid question but did you load the FIT file as a "FIT/GPX Playable File" or a "Workout FIT file"?

To load an activity, you have to select "FIT/GPX Playable File" as the data source. 

"Workout FIT file" refers to a programmed workout (e.g. intervals), and if you select that as a data source and load an activity FIT file, you won't get the results you expect.

If I load an activity FIT file recorded on my FR955 into the simulator, the Activity.Info.altitude values are *reasonable*, although, interestingly enough, all 4 of the following values are different:

1) gps_altitude in FIT file

2) enhanced_altitude in FIT file (well this is expected to be different than 1, since it's probably from the baro)

3) elevation in Connect is different than both 1 and 2 (and elevation corrections have *not* been applied)

4) Activity.Info.altitude (in the sim, when playing back the FIT file) is different from all 3 of the above

But they're all in the same ball park for me

first of all, there are no stupid questions, any help is appreciated!
I configured my app activity as Generic Sport. I published my app as Beta app. It has a few FitContribution fields which I also display on my whatch and all fields have meaningfull values when see them during activity and in Garmin connect including altitude. I download the activity file and tried both in the simulator: Workout FIT File and FIT/GPS playable File. Both provide values which make no sense and differ by thousends not only a few meters or centimeters

I am using Fenix 7x Solar. and API Level 5.1.0 System 8 and Garmin SDK 8.1.0. I do not use GPS because the planned activity is indoor. 
You mentioned the Barometer: I looked up my settings vor the Sensor mode and found it "automatic" is it in my case better to choose another option? I do not know axactly the difference between Barometer and the other static option (I do not know what the name in english this other static option has, sorry)

1173236 said:

You mentioned the Barometer: I looked up my settings vor the Sensor mode and found it "automatic" is it in my case better to choose another option? I do not know axactly the difference between Barometer and the other static option (I do not know what the name in english this other static option has, sorry)

The altimeter/barometer is physically a single sensor, so Altimeter > Sensor Mode and Barometer > Sensor Mode refer to the same setting.

https://support.garmin.com/en-GB/?faq=J2WVA0dss82BNpphPYWq56

The barometric altimeter on the Outdoor watches use barometric pressure to determine changes in elevation as well as changes to the pressure caused by weather patterns. Garmin outdoor watches will continually monitor barometric pressure to determine which mode is most appropriate at any given time. 

Barometer Watch Mode

• Auto (default setting) - The watch will monitor changes and automatically switch between altimeter or barometer modes

• Altimeter - The watch is locked in altimeter mode and all changes in pressure will impact the elevation reading. This mode is best for activities with a lot of elevation changes. 

• Barometer - The watch is locked in barometer mode and all changes in pressure will be considered due to weather and changes in ambient pressure. This mode is best used for activities without a lot of elevation changes. 

Better to use the latest SDK.

I‘m developing datafields for Edge devices which have barometer. For testing in the simulator I use a real ridden Edge activity FIT file which I load via FIT/GPS playable file. The start point of my activity has an altitude of 155 m.

When playing back this file on the simulator, the altitude starts at minus18 m. Every playback the same. But then it seems the increments are correct. Means: the altimeter graph is correct but starts at -18 m instead of 155 m.
Calculations like grade, which are based on altitude, are therefore correct!

I've gotten used to it.

thanks for clarification, I will try fixed setting Altimeter then and come back with the results

mcinner1 said:

When playing back this file on the simulator, the altitude starts at minus18 m.

I noticed the same thing but didn't connect it to the fact that Activity.Info in the sim was off by a "little bit", when playing a back a FIT file.

Maybe in OPs case, they're somehow starting off with a value other than -18, such 1000 or 2000, and this is being used as the "offset"?