Triggered Buffered Counting on Multiple Cards Running Slower Than Expected Hardware: Counter/Timers (TIO)>>Devices>>PCI-6602, Counter/Timers (TIO)>>Devices>>PCI-6601, Counter/Timers (TIO)>>Devices>>PCI-6608
Problem: I have multiple counter cards doing buffered event counting. When I use a start trigger for this acquisition it runs much slower than if I just let them start when the VIs are called. Why is this going slower than expected? Solution: To increase the speed make sure that you are using no more than three counters per card. This way each of the counter channels has a DMA channel to transfer the data. Above that there is not much you can do except try to offset the starting point of each of the counters. When they all run with the same start trigger, they all try to use the Bus to transfer data at the same time. There may be long times where nothing is using the bus and then they all try to use it again. This problem creates periodic backlogs of data, which result in the Counter Card buffer overruns earlier than usual. Synopsis: (1) Make sure you are using DMA Channels. (2) Try to offset the start of the counter tasks by letting them be started by software or having multiple offset hardware triggering. Related Links: KnowlegeBase 2QUB0D7N: Triggering Multiple Counters with a Single Pulse Product Reference: 6601/6602 Users Manual Attachments:
Report Date: 01/24/2006 Last Updated: 03/29/2006 Document ID: 3TNCUTXJ |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
