Input/Output clocks not synced on 6062e

[blibbey]

We are running the PCMCIA card NIDAQ-6062e hooked up to the BNC-2090 set in referenced single-ended mode. We have output channel 0 hooked up to all 16 input channels on the box. When we send a sine wave through the output and into the input, it appears that the clocks used to measure the signal are not synced. This delay varies with the sampling frequency. We are using the Matlab data acquisition tool box to run the card.

[LA 75]

Hello,

PCMCIA equivalents of PCI DAQ cards are often thought to have exactly the same capabilities of their PCI counterpart. However, this is not necessarily the case. For non-buffered operations, such as analog output, the specifications in the catalog are accurate, but for buffered operations, you may notice that there are no deterministic specifications. The reason for this is that PCMCIA cards do not have DMA capabilities. As a result, they use interrupts as their method of transferring data. This is a much slower method than DMA, and the speed of the transfers is limited to a lower rate than that of the PCI cards. That speed is not listed explicitly in the specifications because it is system dependant. So be aware that buffered operations can cause problems with a PCMCIA card in places where they normally wouldn't with the PCI equivalent.

Hope this helps.

Regards,

LA