DAQ question

Hi NG,
I was hoping that some kind soul would grace me with some in-
struction or some pointers to links or something.
Problem: I'm running an SCXI chassis with multiple(5) cards in
it. Two of the cards are 1120's. One of 1120 modules is in slot one
and the other is in slot five. I need to be able to read the voltages
from these analog cards simultaneously.
Currently I have a VI with two parallel loops each doing a read
on one of the cards. Leading into each loop I have a AI config function
and an AI start function. It doesn't work something about resource in
use is the problem. What I think the problem is is that there should be
a group(which I hope someone will explain what this is) that both AI
modules are in and then treat the
m as one "meta-module"?
Am I totally off base?
Any help or suggestions will be greatly appreciated!
Frank Lane
(256)961-4677
[email protected]

In article <[email protected]>,
Frank Lane wrote:
>Hi NG,
>
> I was hoping that some kind soul would grace me with some in-
>struction or some pointers to links or something.
>
> Problem: I'm running an SCXI chassis with multiple(5) cards in
>it. Two of the cards are 1120's. One of 1120 modules is in slot one
>and the other is in slot five. I need to be able to read the voltages
>from these analog cards simultaneously.
Check your SCXI chassis' user manual. I believe that there is a heirarchy
of those cards, and that the 1120 is near the bottom. This means that it
can't be in clot one, one of the others must be ahead of it. I honestly
don't recall the details, but I'm pretty certain that you can't plug the
cable into th
e back of it - it must go into the back of one of your other
3 cards.
Harry
"The art of government generally consists in taking as much money as
possible from one class of citizens to give to the other."
-Voltaire

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Simple Formula SAE car DAQ Question

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thanks for your time

FSAE,
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DAQ questions – Urgent !

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I’m a beginner in the field, so I need a piece of advice from DAQ experienced users:
1. What is the definition of ‘kilo-Symbols /s’ and why the rate unit is not the Hertz?
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My $.02
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Hello,
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Darren Nattinger, CLA
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In running the datalgr example, I get the error NIDAQ32.dll cannot start.... then program exits. Version of NI DAQ is 6.9.2, using MS C++.

In running the datalgr example, I get the error NIDAQ32.dll cannot start.... then program exits. Version of NI DAQ is 6.9.2, using MS C++.

Since this is a DAQ question more than a Measurement Studio for VC++ question, I'd recommend you repost it to the DAQ forum.
Cheers,
Azucena

Can we lock 80 MHz timebase to PXI_CLK10 on PXI-6220 M Series DAQ?

I am using PXI-6220 to measure Frequency/Period of 32768 Hz clock signal, accuracy is very important. I have provided signal to measure on Gate input of Ctr 0 (PFI 9). I am using 80 Mhz Timebase. I want to Lock PLL to PXI back plane 10 MHz reference (PXI_CLK10) which in turn is locked onto the 10 MHz reference via PXI-5600 on Slot 2 (External 10 Mhz standard is connected). so far I don't see a way to lock PLL to PXI_CLK10. Is that possible at all? see the image attached to this message.
Attachments:
M Series DAQ Question.png ‏62 KB

Hello Abhatti,
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Applications Engineer
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VXIpeek occasionally takes long time (few ms)

I am using LabWindow/CVI 6.0 with Window XP for a DAQ.
In average, it takes 2.5us to excute VXIpeek. Also
occasionly it is observed that it takes few ms to execute VXIpeek. The maximum observed time is 19ms
where timing is measured by Timer from VXI library.
And it occurs at 2x10-5 level. I have set the system timeout to 8us which does not help.
regards,
Tiesheng

Hello Josh,
Nice to hear from you. Here are answers for your questions:
Question 1:
My PC 1.8GHz Intel Pentium 4 512MB of RAM
operating system WINDOW XP
VMEcrate 5 slots VME crate from
Solflower Computer Inc.
VMEController VME-MXI-2
Question 2:
PC and VME controller connected via MXI-2 cable
with "MXI-2" card (sorry I do not know the name
of the card which installed at PC).
Question 3:
NI-VISA 2.5.2
NI-VXI 3.2
I did not use NI-DAQ
Question 4:
No error is returned when VXIpeek is excuted
Question 5:
It depends on the VME address (card?). For my card
it occurs at 2x10-5 level. It seems it occurs more
often when VME controller is accessed.
Question 6:
I have not used NI-Spy. I am afraid that NI-Spy may
cause additional delay for VXIpeek due to competation
of CPU. If you think that it will help, I could try
to provide NI-Spy file for you. But you have to tell
me how to do it. Thanks.
Question 7:
Yes, the problem can be repoduced by using a small
code. See attachment. I did not try with VXI
interactive Control where I may unable to get time
information.
Question 8:
Yes, I have removed all cards and only left VME
controller, the problem is still there. See the
results of attachment where only VME controller is
installed in the VME crate.
Sorry, I was unable to add attachment. The code and
output are listed belew:
int main(int argc, char *argv[])
int initial;
uint32 timeout, trlWindow, count, i, resp;
int16 status;
double time0, time1, timeDiff;
void *trlAddr;
// Needed if linking in external compiler; harmless otherwise out of memory
if (InitCVIRTE(0, argv, 0) == 0) return -1;
// Initializes VXIlibrary, allows handling of VXI reads and writes
initial = InitVXIlibrary();
if (initial < 0) {
MessagePopup("MiniDAQ Error", "VXI library initialization failed.");
return (1);
SetSleepPolicy(VAL_SLEEP_NONE);
count = 0;
timeout = 1000L; // Timeout of 1 second
//trlAddr = (void *)MapVXIAddress(0x3, 0x40, timeout, &trlWindow, &status);
trlAddr = (void *)MapVXIAddress(0x3, 0x800000, timeout, &trlWindow, &status);
printf("trlWindow = %u status = %d\n", trlWindow, status);
//Timing Check
time0 = Timer();
for(i = 0; i < 10000000; i++) {
VXIpeek(trlAddr, 2, &resp);
time1 = Timer();
timeDiff = time1 - time0;
if(timeDiff >= 0.002) {
printf("i = %u timeDiff = %f\n", i, timeDiff);
count++;
time0 = Timer();
if (count > 100) break;
else time0 = time1;
printf("count = %u # VXIpeek calls = %u\n", count, i);
UnMapVXIAddress(trlWindow);
return 0;
Output of above program is following, where the unit of timeDiff is in second
as one can see, sometimes it takes few ms to excute VXIpeek
trlWindow = 0 status = 0
i = 4311 timeDiff = 0.003000
i = 9292 timeDiff = 0.005000
i = 18710 timeDiff = 0.004000
i = 41546 timeDiff = 0.004000
i = 64712 timeDiff = 0.003000
i = 87550 timeDiff = 0.004000
i = 94511 timeDiff = 0.004000
i = 507335 timeDiff = 0.002000
i = 511628 timeDiff = 0.002000
i = 520272 timeDiff = 0.005000
i = 522846 timeDiff = 0.003000
i = 524782 timeDiff = 0.013000
i = 528826 timeDiff = 0.009000
i = 530637 timeDiff = 0.003000
i = 547681 timeDiff = 0.004000
i = 556325 timeDiff = 0.004000
i = 560569 timeDiff = 0.012000
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Tiesheng

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Greetings,
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How long of a cable (conducter size yet to be choosen) will I incure significant
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Two questions:
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Is there an infor resource where I can learn about this stuff?
I have a minor electronics background, but I am mostly a medical person.
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Hello,
I am a bit new with using counters to measure frequency. I need to read the frequency from the counters at 100 Hz at least between 0-20KHz so I setup my vi to read it and it works fine if the signal is at a set frequency but as soon as I try to vary the frequency from my generator the vi stops and the daqmx read channel times out and it gives me the error -200284 "Some or all of the samples requested have not been yet acquired " even though I am trying to get them and the vi just stops when the frequency changes. Is this application possible with counters? Am I doing something wrong? I have attached my test vi. I'll appreciate any help. I have a NI9401 with cDaq 9188
Attachments:
Counter Test.vi ‏29 KB

Hi Bertha,
Please take a look at the following example:
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Hello everyone,
When I bought the USB 6212 card, I was impressed with the high input impedance stated for it - 10 GOhm.
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Go to Solution.

Hi Navneet,
The question you have posted is actually a Multifunction DAQ question. You should post these questions in Multifunction DAQ Forums. You would get much faster responses to questions that are posted in the correct forums.
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Dennis Knutson wrote:
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Attachments:
Acquire_and_Save_as_.Wav_File with DAQmx.vi ‏123 KB

This DAQ assitant question confused me

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If you can do it in Measurement and Automation Explorer you can do it with the DAQ Assistant. The only real limitation is hardware, so as long as your board supports what you are trying to do then you can do it with the DAQ Assistant.
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Guohua
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Here is a brief description about wired-or and how to program it.
http://digital.ni.com/public.nsf/3efedde4322fef19862567740067f3cc/8072d2b1f4687276862564d1006ad789?OpenDocument
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Hello Everyone
I´m designing a DAQ board as my thesis work.
I have several questions about input protection, I have searched and searched and I have found only 2 circuits, a crowbar and another one using 2 zenner and a PTC resetable fuse or a ordinary fuse.
My question is, if there is any other circuits that can protect inputs.
The measurement limits are +-20V with a maximum frequency of 100 kHz. At the input there will be a INA163 IA, and then the rest of the circuit. I have to protect these inputs to 230 Vac.
If someone knows any other method of doing this, please reply. I'm pending to the PTC+diodes.
Thank you

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Attachments:
circuit.png ‏17 KB

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