Sequence parameter mapping breaks without notification

[h_yong]

Every once in a while, a stimulus profile or real time sequence doesn't seem to have the desired effect. Several times now we've found that the reason is that a parameter that is mapped to a user channel appears to be forgotten or its link broke. That is, although the sequence tries to change a user channel, the user channel doesn't actually change. The workaround has been to rename the parameter to a new name, and the subsequent run will be successful. Has anyone else experienced this? This is with 2011 SP1.

[Sev_K]

Hi,

I've created a test project that increments a "Count" parameter linked to a user channel inside a test sequence. I've placed an indicator linked to the same user channel on the workspace and it looks like that indicator is always updating whenever the test sequence is running. Can you run the attached project on your end and see if you can reproduce the behavior you've described?

[h_yong]

Hi Sev,

Thanks for the reply. I would like to clarify, however, that the mapping/linking of parameters to a user channel works most of the time. Occasionally as we edit the sequences, it would just suddenly stop working. I am trying to narrow down when this is happening, but it's often hard to tell because it takes quite a bit of debugging to narrow down that it's a parameter mapping that's broken. Typically we think it's a new feature or code that was added, but after some debugging, then we find it's the mapping that's broken and no longer taking effect on the user channel or vice-versa (e.g., the parameter is no longer being updated by the user channel).

[Sev_K]

Hi Harris,

It can be hard to narrow down the cause of this issue since it doesn't happen all the time. Do you think you can create a simple project and try adding some of your code elements (channels, RT sequences) that you think have this issue to see if you can reproduce this issue outside of your main system definition file. I'd also recommend creating a Service Request to address this issue.

[h_yong]

Yes, I can start a support ticket and will pay more attention to the exact steps that cause this on my next stimulus profile project.

[h_yong]

Hi,

I think I may have found a cause of this, or at least a very related issue.

If I have a profile that calls sequence A and that calls subsequence B, and all parameters are passed by reference (perhaps it breaks by value too, but I don't know), then if a parameter's default assignment is changed in subsequence B, the Update Parameters button in the profile doesn't reflect the change of the default assignment, and no error is given. This means that the profile will always continue to assign the parameter with the original default assignment and not the new one which is quite subtle to debug.