# Reference manual: External multiple out events

**URL:** <https://forum.verum.com/t/reference-manual-external-multiple-out-events/1108>\
**Category:** Forum @ Verum\
**Created:** [February 17, 2025, 7:48pm UTC](https://forum.verum.com/t/reference-manual-external-multiple-out-events/1108 "2025-02-17T19:48:39Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![pvberkel](https://avatars.discourse-cdn.com/v4/letter/p/34f0e0/32.png) [@pvberkel](https://forum.verum.com/u/pvberkel)\
**Post date:** [February 17, 2025, 7:48pm UTC](https://forum.verum.com/t/reference-manual-external-multiple-out-events/1108/1 "2025-02-17T19:48:39Z")

</div>

Hi,

I tried to run the example models described in section [5.4](https://download.verum.com/dezyne/manual/dezyne/dezyne.html#External-multiple-out-events) of the _Reference manual_ but discovered that the verification of all models failed. Unfortunately I was not able to determine/understand if or why these errors are valid or invalid.

Verifying component **external\_multiple\_out1** results in the _queue-full_ error:

```auto
verify: external_multiple_out1: check: deterministic: ok
verify: external_multiple_out1: check: illegal: fail
error: queue full in model external_multiple_out1
/home/pavlov/projects/dezyne/all_events/08_external_multiple_out_events.dzn:25:15: error: queue-full in component "J1"

```

Verifying component **external\_multiple\_out2** results in the _queue-full_ error:

```auto
verify: external_multiple_out2: check: deterministic: ok
verify: external_multiple_out2: check: illegal: fail
error: queue full in model external_multiple_out2
/home/pavlov/projects/dezyne/all_events/08_external_multiple_out_events.dzn:65:15: error: queue-full in component "J2"

```

Verifying component **external\_multiple\_out3** results in the _deadlock_ error:

```auto
verify: external_multiple_out3: check: deterministic: ok
verify: external_multiple_out3: check: illegal: fail
error: queue full in model external_multiple_out3
/home/pavlov/projects/dezyne/all_events/08_external_multiple_out_events.dzn:103:3: error: deadlock

```

As I am a new member I am only able to add one attachment. Therefore I only attached images a bout the first model.

 ![Reference manual - External multiple out events-images-0](https://europe1.discourse-cdn.com/flex017/uploads/verum/original/1X/022ad84c362bf887787af885d895ee6ae7336027.jpeg)

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<div class="post-metadata">

**Author:** ![karkob](https://avatars.discourse-cdn.com/v4/letter/k/e19adc/32.png) [@karkob](https://forum.verum.com/u/karkob)\
**Post date:** [February 19, 2025, 11:34am UTC](https://forum.verum.com/t/reference-manual-external-multiple-out-events/1108/2 "2025-02-19T11:34:35Z")

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Hi pvberkel,

In case of external ports you need to specify queue size during verification.  
For example: path\to\dezyne\ide.cmd verify --queue-size-external=3 -I . path/to/model/forum\_model.dzn

You can easily modify VS Code extension command by adding queue size. For more details please type “verify --help”.

Let me know if you have more questions

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<div class="post-metadata">

**Author:** ![pvberkel](https://avatars.discourse-cdn.com/v4/letter/p/34f0e0/32.png) [@pvberkel](https://forum.verum.com/u/pvberkel)\
**Post date:** [February 19, 2025, 2:56pm UTC](https://forum.verum.com/t/reference-manual-external-multiple-out-events/1108/3 "2025-02-19T14:56:09Z")

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Hi karkob,

Thank you this indeed solved the queue-size error for models _external\_multiple\_out1_ and _external\_multiple\_out2_ during both verification and simulation.

Unfortunately this results in a new problem in which the simulation of both models cause a deadlock after the first even. De verification on the other hand does not detect a deadlock.  
For model _external\_multiple\_out3_ the original deadlock has disappeared for the first event but now occurs after the second event during simulation and now the verification also does not detect any deadlock.

I tried different queue sizes but this did not solve the problem.

 ![deadlocks](https://europe1.discourse-cdn.com/flex017/uploads/verum/original/1X/ab151ebf9027df30ca663141b6c3c01991845aed.png)

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<div class="post-metadata">

**Author:** ![karkob](https://avatars.discourse-cdn.com/v4/letter/k/e19adc/32.png) [@karkob](https://forum.verum.com/u/karkob)\
**Post date:** [February 20, 2025, 10:37am UTC](https://forum.verum.com/t/reference-manual-external-multiple-out-events/1108/4 "2025-02-20T10:37:02Z")

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Hi pvberkel,

This is a known bug for the current simulator which has been addressed in the new simulator (which will be available in future release).

It is a rather academic example (two out events on a single modelling event on an external declared port).

When the whole trace is offered to the simulator it works currently, but when single stepping through the trace it reports wrongly a deadlock. (If you ignore the deadlock and just select “r.a” it continues correctly in the ide, just make sure to simulate with extended queue size “simulate --queue-size-external=3”)

 ![image](https://europe1.discourse-cdn.com/flex017/uploads/verum/original/1X/900cac32333baea223ff59f01b0a681619f634e7.png)

Again, sorry for the inconvenience, we are currently making big changes in the core of Dezyne

Cheers,  
Karol

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<div class="post-metadata">

**Author:** ![pvberkel](https://avatars.discourse-cdn.com/v4/letter/p/34f0e0/32.png) [@pvberkel](https://forum.verum.com/u/pvberkel)\
**Post date:** [February 20, 2025, 12:59pm UTC](https://forum.verum.com/t/reference-manual-external-multiple-out-events/1108/5 "2025-02-20T12:59:56Z")

</div>

Hi karkob,

Thank you for the explanation. Nice to know it is already fixed in development.

Cheers,  
Patrick.