In our current practice, we encapsulate the content of DQMH MHL events within subVIs to maintain a tidy diagram and especially to facilitate the seamless propagation of changes to similar projects that use the same implementation.
I think It would greatly benefit the DQMH framework if it could autonomously generate these subVIs as part of its MHL event scripting process.
Lumos adds "Trace VIs", when migrating this code to another PC without Lumos installed When opening DQMH module it asks for all the "Trace VIs" and breaks the code...
It be great to have another option to Remove or Un-prepare project for Lumos Tracking and be able
We have identified that, if multiple clonable module instances are executed and a specific module (e.g. the first launched module) is stopped (no waiting) and afterward all open modules are stopped at once (incl. wait) the "stop module.vi" an error 1 is returning.
Steps to reproduce
Create a project and add a new clonable module
Create a tester VI and implement the code above
Run the VI and see error 1 at second Stop Module.
What is happening in the Background
Situation 1 - "Stall Data Flow" = 0
"Stop Module.vi" 2 runs into "Wait on Stop Sync.vi" and synchronizes stop over rendezvous. The acquired rendezvous size is 3 (Module 1 which is at stopping, Module 2 and Stop Module)
Module 1 is waiting in "Safe to Destroy Refnums.vi"
Module 2 runs into "Close Module.vi"
Last clone instance is fire at (1)
Releasing the Semaphore (2) will wake up module 1 that it is now safe to destroy refnums now. Module 2 runs into "Wait on Stop Sync.vi" (3) and synchronizes over rendezvous.
"Stop Module.vi" and Module 2 waiting for a third participation to join the rendezvous.
Module executes case to destroy Master reference.... and executes "Wait on Stop Sync.vi" (3) with no synchronization as the boolean "Wait for Module to stop?" is on false.
Module 1 executes "Destroy Sync Refnums.vi" (4) and is destroying the rendezvous.
Module 2 and "Stop Module.vi" will be release from the waiting of the rendezvous as the reference is now invalid and returning error 1.
Situation 2 - "Stall Data Flow" = e.g. 2000ms
In compare to the situation 1 the first module is already removed here. The obtained rendezvous has the expected size of 2.
When module 2 enters rendezvous synchronization in "Wait on Stop Sync.vi" (3) the expected amount of participant is reached, and the execution can continue.
In most of our tests, this situation worked fine and did not create an error.
For some situation, we had the behavior that shutdown of the first module seems to be faster as the wake-up from rendezvous of the second module. The module main of module 2 opened and showed error 1. Module 1 seems to destroy the references to early.
Situation 3 - First Module will be stopped with last "Stop Module.vi" call
The shutdown of a module is for this scenario delayed (add a wait 1000ms to exit case of the module)
Stop Module 2 waits for 11 rendezvous participations. (10 module and itself)
One of the previously closed module will destroy the synchronization events and makes the rendezvous reference invalid. => Error 1 at "Stop Module.vi"
The following screenshots are showing an extension of the "Stop Module.vi" and the "Close Module.vi".
The idea is to use a single element queue (SEQ) containing a map of sets. The key of the map refers to a "Stop Module.vi" which waits for stopping all module at the time when the "Stop Module.vi" is executed. The Set contains all Module ID's which should be stopped. Each module checks in its close condition if the SEQ is existing. If so, the module ID will be removed from the sets which containing the module ID. An empty set refers to all required modules have stopped and a notifier which is used for synchronization will be fired. Close Module.vi extention Stop Module.vi extention
With those extensions, all three described scenarios should be fixed. In addition, should it be possible to stop all module and launch in the background new ones, the stop and wait will wait until all those modules ID run at the stop execution are finished.
I added the project which the extensions and tests to the post.
Addition
I'm not sure, but I think that with the described change, destroy of the Module's Semaphore (1) should be done with the boolean condition of the First & Last Instance (2). (Red line)
Please let me know if you need any additional information and details.
As users of SVN for source code control, we rely on SVN-Locks to maintain a conflict-free development environment when collaborating with multiple project team members.
When working on DQMH Projects as a team, it would greatly enhance our workflow if we could selectively apply SVN locks to specific subsets of the project.
Currently, the DQMH scripting necessitates write access to the entire project, limiting flexibility in group collaborations.
Is it feasible to consider modifying this behavior to provide increased flexibility and efficiency for group work?
For DQMH modules written prior to DQMH 7, helper loops will unlikely have the "DQMH_HELPER_LOOP_NAME" string constant wired to the error helper VI as shown below.
This idea is to propose a new test be added to DQMH Validate Module to check that all helper loops have this string constant present.
Today when creating adding a module template it is not possible to set a 'human readable' name for template.
The template name is the module's library name. Having a field to specify a more friendly name could be useful (could be set by default withe the module's library name though).
Using DQMH 7.0.1.1316 (currently the latest version), the error message generated inside the Default case of the Message Handling Loop is "The invalid message string "%s" was received in the Message Handling Loop for module "%s"."
"The invalid message string "%s" was received in the Message Handling Loop of module "%s"." might be a small improvement.
Most of the time we create multi-layer applications, and bottom modules need to share information that might have to cross several upper layers.
To avoid coupling and jumps between any non-adjacent layers, we have to create similar broadcast in the parent modules to repeat child broadcast one layer upper.
It would be interesting to have a utility that 'copies' an existing broadcast from one module into another.
And maybe have an option to code the forwarding :
automatically register for child broadcast in the parent if not done already
in the selected braodcast EHL case, map broadcast arguments onto parent broadcast VI inputs
I guess the same thing can be done when the communication needs to go down the layers, and therfore applied to requests.
In DQMH 7.0 you can create private requests now. This is a feature that I really like and the more you use something, the more ideas come to you.
In my current project I created a private request and shortly after I realized, that I need to call this request from another module. I tried to convert the private request into a public request, but this wasn't easy.
So here comes my idea: why is the conversation (public requests → private requests and privat requests → public requests) not included in the Convert DQMH Events dialogue? That would be the place where I would intuitively look for it.
Include a "checkbox" onto the Add New DQMH Module dialog panel that is labelled "Include a Helper Loop"
If the user checks this checkbox, a helper loop is automatically added to the Main.vi
The helper loop would not be a sub-VI, but simply a third loop on the main.vi block diagram.
A Wake up Helper Loop request is automatically created and included in a Private Requests virtual folder
Make the helper loop generic as per Sam's suggestion. My suggestion is to have three user events: 1) Timeout 2) <Stop Module> 3) <Wakeup Helper Loop>
Label the additional "Register for Events" node something different from the other "Register for Events" node, ie. DQMH_REG_EVENTS_HELPER_LOOP (so that the Validate tool does not raise it as an issue)
When generating a helper loop for new cloneable modules, ensure that in the "Wakeup Helper Loop" and "Stop Module" user events, that the Addressed to this Module.vi is used.
It would be awesome if the DQMH validation tool could go back more than one version.
eg. If you open an old piece of code (that was written in say DQMH 4.2), the only way to upgrade it to 6.1 is to one version at a time, upgrade the code step by step. This would mean the following:
- Install DQMH 5.
- Run Validation tool
- Install DQMH 6
- Run Validation tool
- Install DQMH 6.1
- Run Validation tool
This is a rather painful process, and when faced with this, I have decided to simply implement the module again starting from the latest version, and porting the code over rather than go through that.
Neither approach is obviously ideal.
We really need a tool that can convert an older module up to the latest standard. This will become a more common problem now that we have DQMH-based code out there from 2018 onwards. The more people use it, the more this problem will surface.
I have 'barebones' singleton and cloneable module templates that I always use when creating new DQMH modules for projects. I started with the shipping module templates and removed:
- 'Do Something' events
- All #Bookmarks
- Simulate EHL/MHL error buttons
I propose DQMH ship with these simple module templates. They help save several minutes when creating a new module. I'm not suggesting changing the project template, but rather simply adding two new options in the Add New DQMH Module drop-down:
When you create a Request and Reply event, the scripter creates such code in the MHL :
And I always end up refactoring it this way :
('Status update' related code can be ignored if it is a bit too much). Is it possible, using scripting, to directly script that so we don't have to do this each time ?
I am aware of the note that is being shown on the "Remove DQMH Event" that states:
" NOTE 2: You cannot remove the last private event from a DQMH module. Once a private request has been created, the module requires at least one private event to be present."
The request i believe would come in handy, is that instead of "hiding" or "not showing" the one and only private request, to instead show it as available for deletion, and when pressing OK, populate the information on a popup that shows what NOTE 2 said.
This with the objective of not giving the user the notion that DQMH scripting tools are broken, especially the ones just beginning to use DQMH.
Open the block diagram and find the event frame configured for this request (It might no longer be listed and instead say something like “Unknown Event (0x0)”).
Open the block diagram and find the event frame configured for this broadcast. (It might no longer be listed and instead say something like “Unknown Event (0x0)”.)
All DQMH modules come with a Module Timeout--constant.vi:
This value defaults to 5 seconds, but I've worked with many modules over the years (usually having to do with serial devices) where this value is modified. I find it tedious to have to dig into the timeout VI any time I want to find out what the timeout actually is. Especially when I'm working with multiple modules at the same time that may have different (legitimate) timeout values. So I propose the following:
1) The default modules that ship with DQMH should include the timeout value in their icons:
2) There should be a Validate test that ensures the Timeout VI icon displays the correct value, and provide a fixer that will update the icon if it does not.
I want to be able to try to fix or poke the code more when an error occurs in the API Tester. The opportunity of going to the block diagram or attempting to send a different request goes away because the API Tester, by default, closes when an error occurs.
How I propose fixing it:
The first thing that I change on an API Tester at the first error is to remove the OR connected to the stop terminal in the loop and add an error indicator at the end instead of the Simple Error Handler and connect a local variable for the error. Would you please vote to have DQMH do this by default and have a validator to modify existing API Testers?
Current API Tester:
Proposed change:
Thanks,
Fab (yes, being the DQMH Lead Architect does not guarantee that all my wishes are turned into reality 😉 )
