‘Error -200452 occurred at Property Node DAQmx Channel’ When Using Counter Inputs On a 62xx Card Hardware: Counter/Timers (TIO)
Problem: An application using multiple counter pulse tasks crashes when run and generates error -200452.  DAQmx counter tasks use Direct Memory Access (DMA) as the default data transfer method since it is the fastest option. Every card has a specified number of DMA routes available for use, and if you attempt to communicate with more channels than the card has DMA routes for, the application will generate an error. Solution: Use a channel property node to specify the data transfer method for channels that exceed the available DMA routes. The next best option is ‘Interrupts.’  The DAXmx Channel Property Node can be found on the DAQmx palette under Measurement I/O. Place this node and connect the task input to the counter task you wish to configure. The Data Transfer Mechanism Property can be found by clicking on Property and selecting Counter Input » General Properties » More » Advanced » Data Transfer and Memory Data Transfer Mechanism. Set this property to write and create a constant for the input. You can now select any of the various methods for the transfer method. The included example has four counter input tasks. The 6602, for example, has 3 DMA routes. One of the tasks in this application does not have the channel property node in order to demonstrate that it defaults to DMA even if all routes are full. If you use the 6602 with this application and have all CI.DataXferMech inputs set to DMA, you will see the error in the problem description. Try changing any of these transfer method constants to interrupts and notice how the program executes without error. Related Links: KnowledgeBase 3L5FO27U: Why Do I Get Error 200452 When I Use Certain DAQmx Properties With My DAQ Board? KnowledgeBase 3289EL74: Common NI-DAQmx Error Codes and Solutions: Codes -200300 to -200999 KnowledgeBase 2XQEAPQJ: Common NI-DAQmx Error Codes and Solutions: Codes -200000 to -200299 and -50103 Attachments:  
Report Date: 11/21/2006 Last Updated: 02/11/2008 Document ID: 43KB81BE |
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