Timing of the DASYLab Action ModulePrimary Software: Other NI Software>>DASYLabPrimary Software Version: 6.0 Primary Software Fixed Version: N/A Secondary Software: N/A
Problem: My DASYLab worksheet uses a two-channel Action module where channel 0 generates data in a Latch module, which stores the value of a variable and, on the same event input channel , I set the variable to 0. Why does the latch module always output 0 and not the correct value of the variable ? Solution: The reason for this behaviour is the timing of the Action module: An action can only be processed once per block. If an asynchronous Action is released, a one block time delay between the appearance of the event (in one block) and the release of the action (in the next block) arises. A synchronous action solves this time delay because the action will be released in the same block as the event is detected. This type of action uses a lot of computation time so the total number of synchronous actions is limited to 16 per worksheet. Another problem can arise if more than one action influences the same receiver module at the same time; the receiver may calculate its function more than once per block. In this case different data streams may emerge which can not be controlled. The action module is event driven; the order of the channels is not the order in which actions are released. If you try to release two actions on the same event, it could be possible that the order is not the order you like. To overcome the problem, you should set up two different events for your actions. One technique for this is to use the "Increment var no. x after performing action" option for the first action, and define the second event as "Global var x changed" for the second action. Related Links: Attachments:
Report Date: 05/06/2002 Last Updated: 12/07/2004 Document ID: 2L5DC20Z |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
