National Instruments 653X Manuale Utente

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E-1
E
Optimizing Your Transfer Rates
Use this appendix to determine the maximum transfer rate for your device, 
optimize transfer rates, and to see example benchmark results.
Determining the Maximum Transfer Rates
The maximum sustainable transfer rate a 653device can achieve depends 
on the minimum available bus bandwidth and is based on your computer 
system. The maximum sustainable transfer rate also depends on the number 
of other devices generating bus cycles, your operating system, and your 
application software. The maximum sustainable transfer rate is always 
lower than the peak transfer rate.
The average bus bandwidth from highest to lowest is in the following order:
PCI/PXI-6534
PCI/PXI-6533
AT-DIO-32HS
DAQCard-6533 for PCMCIA
With the 6534 devices, if the data you are acquiring/generating fits in the 
onboard memory, the transfer rate is not limited by the bus bandwidth, 
only by the maximum transfer rate based on the protocol used. These rates 
are listed in Table E-1. The peak transfer rates are based on using a 
1 meter cable.
Table E-1.  Peak Transfer Rates Based on Mode and Protocol Used
Mode/Protocol
Peak Rate (MS/s)
Handshaking 8255
5
Handshaking Level-ACK
3.33
Handshaking Leading-Edge Pulse
3.33
Handshaking Long Pulse
3.33