X Series is here – New Counter Features!

[stilly32]

Hey All,
The new X Series Multifunction DAQ devices have been announced – check them out here.
I’m posting here because I think X Series has several new counter features that many on this forum have been looking for. The user manual will have all of these details and more with timing diagrams but I thought I’d summarize a few of the sexier features and open it up for comments/feedback.

 
First off – what stayed the same between M Series/TIO counters and X series counters? The pinouts between M and X series are the same so the PFI lines and default counter pinouts are the same. The DAQmx programming is the same (you’ll need DAQmx 9.0, it should be up this afternoon) and all the functionality that was supported by M Series is supported by X Series, though a few behaviors may have changed. Counters are still 32 bit.

Now on to the fun stuff – the big one that I tend to overlook: X Series has 4 counters per board! They all have the same features and Freq Out is still there too (with an additional 20MHz timebase).

Timebases: X Series devices have 100MHz, 20MHz and 100kHz timebases. Note the difference between 80MHz on M series and 100MHz on X series. DAQmx will take care of the difference for you, unless you were programming in terms of ticks and hardcoded in numbers based off of a 80MHz clock. 

Counter FIFOs: X Series has a 127 sample FIFO per counter. When combined with PCIe/PXIe, our benchmarked buffered counter rates went from ~350k on M series (with a 2 sample FIFO) with a single counter to 10MHz on all four counters (160MB/s streaming rate). The FIFO also allows us to implement…

Buffered Counter Output: Probably my favorite new feature. You can now use a multi point write on counters and write out a buffer of pulse values. There are two timing modes for this: implicit and sample clocked. With implicit timing, every idle/active pair you write is generated as a pulse. You can vary the idle/active time for every pulse in your pulse train. Check out the "Gen Dig Pulse Train-Buff-Implicit-Cont.vi" shipping example. With sample clock timing, the idle/active time are updated every time a sample clock is received. Check out the "Gen Dig Pulse Train-Buff-Ext Clk-Cont.vi" shipping example. These modes give you much more control over your waveform – now everything about it can be hardware timed. Also, I’ve benchmarked the output rates at 10MHz on all four counters at the same time.

Finite pulse train with one counter: Each X Series counter has an Embedded counter paired with it. The embedded counter isn’t directly programmable, but it does allow you to do counter operations on one counter that used to take two.  A finite pulse train used to take two counters – one to generate the pulse train and one to gate it. Now a counter generates the pulse train, and its embedded counter counts the TCs and disables the counter when it reaches the number of pulses to generate.

More sample clocked measurement modes: Edge counting and encoder measurements always supported sample clocks, all other counter measurements were implicitly (timed by the measurement waveform) timed. With the addition of the sample clock terminal to the counters now all counter measurements (except for semi-period) support sample clock timing. You can now get the pulse width of the pulse just before the sample clock rather than getting all the pulse widths and figuring out where they happened in time. Why not semi period? We added a new “pulse” measurement instead that returns a sample that contains the high and low time (or high and low ticks, or frequency and duty cycle) so for each sample clock edge you get a full pulse spec. Semi period still supports the same measurements it used to, just not sample clocked. Speaking of sample clocked…

Sample clocked frequency/period measurement with averaging: X Series still supports the three frequency modes: Low frequency 1 counter, 2 counter High Frequency and 2 counter Large Range. In addition it supports sample clocked averaging. This is essentially a method that is high accuracy method based on the sample clock rate. With the same measurement time it has the same accuracy as the Large range mode but it doesn’t take two counters.  Note, counters do not have their own internal sample clock so you have to provide them with an external signal.

Hope this helps,
Andrew S
National Instruments
Multifunction DAQ Product Support Engineer

[stilly32]

DAQmx 9.0 is now up.

Cheers, 

Andrew 

[Chris2008]

Hi all

this is probably not the right thread to post this message but I stumbled upon it when playing around with the counters on the new X series boards: The Borland (aka Codegear, aka Embarcadero) import libraries shipped with DAQmx 9.0 are probably not updated and lead to linker errors (for me it was DAQmxSetCOEnableInitialDelayOnRetrigger()). Converting the MSVC imort library to Borland format using coff2omf.exe fixes the problem.

Best regards

Christian

[KrisJa]

Hi guys,

I drew up a schematic of one of the applications I need to get running in our lab. To recap:

1)      We have several piezo controllers for nanopositioning of samples under a microscope, some of them driven by a digital circuit that handles coordinate programming and trigger line programming (for syncing detectors to the piezo motion), other controllers are analog and need to be driven by voltages.

2)      We would like to emulate the behavior of the digital controller using the analog HW (we have much more analog controllers than digital ones).

3)      The basic implementation is like this (see also slide one in the attached pdf file) and runs perfectly:

a.       A global pulsetrain ticks with a certain frequency

b.      At each tick a voltage is written on an AO line and this tick is also sent to an RTSI line to sync multiple detectors

4)      To fully emulate the digital controller we also need to implement 4 trigger lines that exist on the digital controller. These trigger lines allow for fully programmable pulsetrain output that is in sync with the movement of the piezo. Slide two in the attached pdf illustrates what is needed. These trigger lines allow for much more intricate syncing of our detectors (only measure during certain parts of the motion instead of all the time).

After a lot of thinking and experimenting with the existing M series boards back here I came to the conclusion that the desired behavior is not possible with an M series board since they only allow for the output of “simple” pulsetrains with a given frequency.

Looking at this webpage (http://zone.ni.com/devzone/cda/tut/p/id/9384#toc3) however, I think that the X series board would offer exactly what we need since it allows for buffered counter output that enables definition of very complex pulstrain “shapes”.

Looking at the schemes I provided, could someone confirm that the X-series covers our needs? If this is the case, we would be interested in purchasing these kinds of boards.

Cheers,

Kris Janssen

[stilly32]

Hey Kris,

I believe that X Series counters will do what you need, but I also think M Series can. To make sure I'm understanding these diagrams correctly: All of these trigger lines are essentially divide downs of  the "Global Timing Frequency pulse train" but at varying divide downs. So for trigger line 2, it looks like you need 50 ticks low,~128 ticks high, then some varying samples. This is exactly the idea of the implicit buffered pulse train generation. Each sample you write is a pulse that can be specified in terms of high and low ticks. So if you know where you need the pulses based off of the timebase, you can generate the 4 trigger lines you show here. This does assume that you know the pulses needed to write beforehand and it is not based on some feedback from the circuit. 

To do this on M Series, the concept is the same but you would use correlated digital output with the  Global Timing Frequency pulse train as the sample clock. Instead of writing a pulse of 50 ticks low and 128 ticks high, you would write 50 0s and 128 1s and each sample clock would generate that sample. You could write 4 different lines with 4 different patterns of 0s and 1s to generate your 4 trigger lines. Again, you would have to know your pulse train before hand and writing the data is a little less intuitive than on X series, but both should work. 

If you have questions, let's follow up on this thread -  multichannel synchrobized counter output daqmx C#

Cheers,

Andrew S

[KrisJa]

Hey Andrew,

I thought about your comments on the M series board and I have some additional questions. I'll post them in the thread you suggested.

Cheers,

Kris