DAQ USB 6341 et boucle cadencée plante après un temps d'éxécution

Bonjour,
J'ai un souci avec un code (voir fichier joint Labview 8.6)
Je réalise sur un DAQ 6341 une sortie horloge laquelle est reliée sur une entrée numérique qui me sert d'horloge à une boucle cadencée (cadencement à 250ms). Dans cette boucle je ne fais qu'afficher le temps écoulé en comptant le nombre de top qui sert au cadencement de ma boucle. 
Lorsque j'exécute tous ce passe bien jusqu'à environ 247 seconde ou tout s'arrète:
Je n'ai plus mon signal d'horloge que j'ai créé sur le DAQ, et le code Labview semble planté.
Lorsque j'effectue plusieurs foi l'exécution du code le plantage intervient toujours aux alentours de de 247 secondes!!
Je ne comprend pas ce qu'il se passe, voyez vous quelque chose dans mon code qui ne colle pas????
Merci
Résolu !
Accéder à la solution.
Pièces jointes :
Test_sequence-cadence.vi ‏29 KB

J'ai trouvé d'ou vient le problème!
Pour ceux que cela intéresse il faut pour le VI DAQmx Cadencement câbler l'entrée "mode d'échantillonnage" avec "Echantillons continus".
Dans la doc de Labview il est indiqué nul par la valeur par défaut de cette entrée si on ne la câble pas!! Par contre je ne comprend pas pourquoi c'est seulement au bout de 247 secondes que la tache s'arrète???????
Ci joint le VI fonctionnant (Labview 8.6).
Pièces jointes :
Test_sequence-cadence.vi ‏39 KB

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