What is the limiting number of developer fields that can be added under session?

I am trying to add 21 developer fields in a session using session.CreateField.  

It always crashes on the line adding the 17th developer field. I have tried a few different things, even swapping order, but same error occurs (runtime system error "Failed invoking <symbol>").  Is there a limit of 16 on the number of developer fields I can add?  Is there any way around this?

I am using SDK 2.4

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  • This is actually a bit more complex as I understand.

    While you may be able to use 16 in your DF, I think that's the a limit per activity, not per DF.

    So if a user has your DF with 16 and another DF that uses 1, one of the two DFs will crash.

    Also, You probably want to update your SDK, as the 2.4 one is years old, and missing many devices, features, bug fixes, etc.  The current SDK is 3.1.9

  • If you're doing a device app, you don't have to worry about impacting DFs though.

  • Please vote for this: https://forums.garmin.com/developer/connect-iq/i/bug-reports/please-can-the-sdk-documentation-be-more-developer-friendly-and-searchable-and-complete

    The number of fields under different conditions should be something that is available to be known per device.

    Also, the guidelines Jim supplies don't seem to match my observations in the wild.

    This seems to be pretty basic technical limits that Garmin and only Garmin can provide the answer to, but that Garmin and only Garmin should also find it very easy to provide the answer to.

  • There was a DF (I forget which one) where it was using a bunch of developer fields, and the developer released a "lite" version with fewer developer fields due to this.  The DF itself ran fine, but it impacted other DFs.

  • pretty basic technical limits that Garmin and only Garmin can provide the answer to

    I think you are just reinforcing my case!

    When even you don't know from your encyclopaedic knowledge and experience, it is safe to assert that the value is unknowable by anybody outside of Garmin.

    However...

    The techs who actually set the limits and build the devices can know this and other values absolutely.

    For example... that old chestnut about how many CIQ DF a device can support. You've given me a few answers "to the best of your knowledge" and yet there is an absolute, indisputable, hard-coded, programmatic limit that is enforced by Garmin.

    I won't get into the politics or workload to get it there, but I will state my belief that this information should be included in the developer docs as an appendix or (better) in a reworked, searchable and therefore useful "compatible devices" page.

  • and yet there is an absolute, indisputable, hard-coded, programmatic limit that is enforced by Garmin.

    I don't believe that there is such a hard-coded limit. It will likely depend on how the particular device is configured and how much space each field consumes.

  • For example; my 735xt will only allow me to use 3 CIQ datafields in one activity. This is an absolute, indisputable, hard-coded limit that is absolutely known and knowable to a Garmin developer. 

    I only discovered it by accident. 

    Similarly, there is an absolute - and smaller - limit for many other watches. I only know this on faith - I trust Jim - but it is not possible for me to know without owning the devices in question. 

    _That_ is the kind of absolute, hard-coded limit I mean that should be available. 

    However, there are _many_ of these...

  • You've complained about the number of CIQ DFs, probably since your first post, and what I've said is EASILY confirmed if you looked in the device forums.  You don't need to trust me or have the device.

    The 735 and Epix are odd, but all other watches, it's a max of two.

    And why exactly does that matter to most CIQ developers?  If their DF can be added, all is wonderful! Slight smile

    Exactly what hard coded limits don't you know?  There are many things you can see just using the sim.  Post a list of the "many of these"!

    Between long timers like me and Travis and newbies, we can probably tell you an easy way to find out.

  • So please can you tell me an easy way to find out?  For example, on Edge520Plus, SDK3.1, what is maximum number of CIQ DFs?  Is this dependent on datatype?

  • The easiest way is to look through device forum for those devices, and if you can't find it, post a question there.  If someone has the device, it's really easy for them to check.  When you go to add a field, in the CIQ section it will say

    Connext IQ Fields

    x/y

    Where x is the number of CIQ fields in use, and y is the max.

    I'm pretty sure it's like the e520 and 4.  but it could be like the e530/e1030, and be 10 (those are the two possibilities for edge devices).