How to generate and output 3 TTL square waveforms with different pulse widths using counters of NI 6034E

Question

Hello
I just have a few questions.
 I am using the NI 6034E DAQ board in order to
generate simultaneouly 3 different TTL digital signals, with different
pulse width, and output these TTL signals to an external circuit that I
am using for this application.
The following pattern of the TTL pulses will look like this:
01010101 01010101
00110011 00110011
00001111 00001111
From
what I understand,  I have to use the 2 counters, Ctr0 and Ctr1, to
generate the TTL pulses that I desire, because the DIO lines are
software timed only and I will not be able to produce a deterministic
output period using these DIO lines.  Am I correct?    Also, do I have
to use a separate counter to generate a separate TTL digital pulse.  I
need 3 different TTL pulses and there are only 2 counters for this DAQ
device.  The three generated TTL signals will be feed to an external
circuit.  Concerning the hardware connections for my application, I
assume that the generated TTL signals will be output from
GPCTR0_OUT(pin 2)  for counter 0 and GPCTR1_OUT(pin 40) for counter 1
of the NI 6034E. Is this correct?  Is there any way that these TTL
signals can be output from three DIO lines(DIO0...2). 
Here is some code that I plan to use in order to do this:
 #include <NIDAQmx.h>
static TaskHandle gTaskHandle = 0;
DAQmxCreateTask ("", &gTaskHandle);
DAQmxCreateCOPulseChanTime (gTaskHandle, "Dev1/ctr0", "", DAQmx_Val_Seconds, DAQmx_Val_Low, 1.0, 2.0, 2.0);
DAQmxCreateCOPulseChanTime (gTaskHandle, "Dev1/ctr1", "", DAQmx_Val_Seconds, DAQmx_Val_Low, 3.0, 4.0, 4.0);
DAQmxCreateCOPulseChanTime (gTaskHandle, "?????", "", DAQmx_Val_Seconds, DAQmx_Val_Low, 7.0, 8.0, 8.0);
DAQmxCfgImplicitTiming (gTaskHandle, DAQmx_Val_FiniteSamps, 5);
DAQmxStartTask (gTaskHandle);
DAQmxWaitUntilTaskDone(gTaskHandle)
DAQmxErrChk DAQmxStopTask(gTaskHandle)
DAQmxErrChk DAQmxClearTask(gTaskHandle)
I believe this code should generate the 3 TTL square waveforms that I want for my application.
Please provide me with some feedback.  It would greatly be appreciated.
Thank You

Answer 1

 Hi,
The NI 6034E is a multifuntion DAQ device, this means you have:
  (2) counters
  (8) DIO lines (software timed)
  (16) AI, single ended
  (0) Analog Output
 You have a couple choices here:
   1. Software timed digital output of all three signals, max 1khz loop rate, non-deterministic.
   2. Hardware timed digital output of 2 signals, max 20Mhz.
   3. Hardware timed digital output of 2 signals and software timed digital output of 1 signal.
   4. Find another NI MIO board such as the NI 6251. This board will do 10Mhz pattern generation for (8) DIO lines.
For the hardware connection, you are correct, the output for the counters will be taken from pin 2 & pin 40.  Here's the pinout for the NI 6034E for reference:
The output of the Counters can be routed to some of the PFI's or to the RTSI connector. You can see this in MAX
Message Edited by Matthew W on 11-19-2007 01:24 PM
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