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为什么获取时间/日期（秒）和时间计数器的时间分辨率不一致？
硬件: PXI/CompactPCI>>Controllers
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问题: 获取时间/日期（秒）这个VI似乎有1ms的分辨率，但有时却更长。为什么当我仍然能使用时间计数器来获取1ms的分辨率会发生这样的问题？
解答: 获取时间/日期（秒）这个VI从Windows的日历中获得信息，而时间计数器这个VI则从您的计算机系统的BIOS中获取tick的个数。每次您重启计算机后，tick的个数就会被复位，且它的精度为1ms。Windows日历的更新率却不同，因此并不会给出期望的1ms的分辨率。Windows日历的更新速率大概是这样的， Windows XP 专业版的是60Hz.，这个速率将会使获取时间/日期（秒）这个VI的时间分辨率大致为16.66 ms。
相关链接: KnowledgeBase 3PJC3B8: How do I Convert a Date/Time String into a Timestamp Constant in LabVIEW?
KnowledgeBase 2G27ANEW: Wait Until Next ms Multiple.vi Does Not Wait Properly on First Loop Iteration
KnowledgeBase 0EF854SG: Differences Between Wait (ms) and Wait Until Next ms Multiple
DeveloperZone: Software Timed Loops using Wait (ms) and Wait Until Next ms Multiple
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报告日期: 03/03/2006
最近更新: 01/21/2009
文档编号: 3V2FAKHL