06-28-2012 05:41 PM
Hi,
Solved! Go to Solution.
06-28-2012 06:02 PM
If the sample rate of the controller is set to 300 us, that would meean indeed it samples the channels in that speed. The 9215 does not have a free running clock like the delta sigma modules. It samples when the scan is asking it to do so. The ethercat connection is not build for high speed but for synchronization. All of your three modules are sampled at the exact same time with jitter in ns range.
The 300 us are probably the maximum of what you can do on cRIO and you will get an error if you try to further increase the rate.
One option to increase sample speed would be to move to the FPGA of the 9144 chassis. The FPGA could max out the 100 kS rate and you could make your analysis at the fpga and then send your analysis result over to the cRIO chassis for further decision.
PXI instead of cRIO would allow to achieve up to 10 KHz sample rate.
DirkW
06-28-2012 06:21 PM
Thank you so much for the explaination.
Now I am running the program on cRIO at 300us scan period. I want to show a pulse on to a oscilloscope whenever the acquired sample exceeds a predefined threshold. I have acheived this by writing a string "111111" on the serial port and connected the write pin to the oscilloscope. But theoritically, it should show it in milli seconds, but it takes around a second to show it. Is it because of some delay on the serial port?
Will a device such as NI 9401 be suitable for such purpose?