About PXI-6220 PXI-6221

We want to use PXI-6220 or PXI-6221 to design a system. And we will use the CVI or Labview, but we cannot find the PROGRAMMING MANUALS of PXI-6220 or PXI-6221.Where can I get them? Thanks!

Hi wenyan,
You can program both the PXI-6220 and the PXI-6221 using the NI-DAQmx driver. The following tutorial is a very helpful:
Learn 10 Functions in NI-DAQmx and Solve 80% of Data Acquisition Applications
Also, both LabVIEW and CVI come with various data acquisition shipping examples (Help >> Find Examples). I suggest using those as starting points.
If you've installed the DAQmx driver, you should be able to find DAQmx Help from (assuming you're using WindowsXP) Start>>Programs>>National Instruments>>NI-DAQ
More information on the DAQmx functions can be found:
NI-DAQmx Help (User Manual)
Hope this helps,
Lesley Y.

Similar Messages

Pxi 6220 redefining terminal routes

Hello,
In MAX explorer, the pxi 6220 routes tab shows a direct route from PFI6 to the counter 1 gate (ctr 1 to be used for low freq counter) and an indirect route through counter 1 to PFI 4. But from the terminal diagram for the card, it looks like PFI 4 IS the counter 1 gate.
However, in LabVIEW terminal rerouting VI, I can select PFI 6 as the source and PFI 4 as the destination (there is no option to select counter 1 input as destination), but the counter does not appear to be counting. At the moment the input on PFI 6 is a "TTL" level square wave, but I don't get any counts.
Does anyone have any experience with this...any suggestions on what to try to determine where the problem is?
Best Regards,
Chris

Hi Chris,
If you are unable to see properties in your property node, I would first
check to see if you are filtering the properties according to the devices in
your system. There is a KnowledgeBase article outlining the property filtering
which can be found here.
Also, if you right-click the section of the property node where the
property is displayed, you should see a selection at the bottom titled “Select
Property…” If you click this, a browser should appear with all the properties
of DAQmx Channel.
If you are unable to select the property by right-clicking on the
property node, you can also navigate to View » Class Browser and select the
DAQmx object library and DAQmx Channel class. Hope this helps,
Daniel S.
National Instruments

DC crosstalk between PXI 6220 channels due to high source impedance

Dear all,
I’m trying to digitize 10 single ended signals simultaneously with the PXI 6220. The source impedance for each signal is 1.5meg which should not be problem since the input impedance is >1G. Bias currents are taken in account and give only an offset error (assuming that they are constant). Crosstalk according datasheet is -75db at 100khz which is fairly okay for my app however the source impedance is not indicated for that specification. When I acquire data (Dc voltages) from the PXI6220 i see unexpected high crosstalks (again source impedance 1.5meg). The sample rate is 200Hz and I connected only one AIGND pin to the reference of the system. I verified whether the GND is okay by connecting one input pin directly to 5V (Rout=0) . This channel indicates 5V while the others (Z=1.5meg and grouded) give non -zero value of voltages (2V). DC leakage between channels in the cabling is not verified yet.
1)      Does anyone have a clue why I observe so much DC crosstalk at high source impedances.
2)      Does the PXI6220 digitizer have 16 parallel channel or does it make use of an multiplexer.
3)      Do I have to connect all AIGND’s to my system’s reference or is just 1 okay.
Patrick

Patrick,
I think the culprit is probably the multiplexer and not the amplifier input impedance. Look at the settling time graph on page 2 of the speicifcations. At 100 ppm error (which several source impedance curves cross) the settling time increases exponentially with the source impedance. 4 us at 1kohm, 6 us at 2 kohm, 13 us at 5 kohm, and 25 us at 10 kohm. It is probably not a reasonable to extrapolate that data more than two oreders of magnitude, but it is not unreaonable to expect some problems even at your slow sampling rate.
The user manual has this to say (pg 4-7):
M Series devices are designed to have fast settling times. However, several
factors can increase the settling time which decreases the accu racy of you r
measu rements. To ensu re fast settling times, you shou ld do the following
(in order of importance):
1. Use Low Impedance Sources —To ensu re fast settling times, you r
signal sou rces shou ld have an impedance of <1 kΩ . Large sou rce
impedances increase the settling time of the NI-PGIA, and so decrease
the accu racy at fast scanning rates.
Settling times increase when scanning high-impedance signals du e to
a phenomenon called charge injection. Mu ltiplexers contain switches,
u su ally made of switched capacitors. When one of the channels, for
example channel 0, is selected in a mu ltiplexer, those capacitors
accu mu late charge. When the next channel, for example channel 1, is
selected, the accu mu lated charge leaks backward throu gh channel 1. If
the ou tpu t impedance of the sou rce connected to channel 1 is high
enou gh, the resu lting reading of channel 1 can be partially affected by
the voltage on channel 0. This effect is referred to as ghosting.
If you r sou rce impedance is high, you can decrease the scan rate to
allow the NI-PGIA more time to settle. Another option is to u se a
voltage follower circu it external to you r DAQ device to decrease the
impedance seen by the DAQ device. Refer to the KnowledgeBase
docu ment, Decreasing the Source Impedance of an Analog Input
Signal , by going to ni.com/info and entering the info code rdbbis .
A buffer per sensor is the best fix.
Lynn

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,
Based on the diagram that you have attached, the M-Series card can PLL to a higher accuracy clock such as the PXI Clock_10. The way to configure this change using the DAQmx driver is route the signals using the DAQmx Timing RefClk.Src Timing property node. Once you place down this property node, and specify the RefClk.Src attribute, you select the PXI-Clk10 as your reference clock source. This will discipline the 80 MHz Timebase of the DAQ card to the 10 MHz reference clock of the PXI chassis. Which chassis are you using? Also, how have you PLL'ed the 10 MHz backplane clock to the PXI-5600 Downconverter?
Michael L.
Applications Engineer
National Instruments

Repetative trigger from PXI-6733 to PXI-6220

I am running a PXI-6733 in continuous mode and want to send a trigger pulse from the 6733 to a PXI-6220 at the start of each cycle. I will also want to do this in finite sample mode. I have used a DAQmx Connect Terminals VI to connect the trigger channels. But I cannot find how to set the 6733 StartTrigger as an output or how to synchronize it with the analog output. Any suggestions would be welcome.
Bob

Since your AWG needs to send the 6220 the trigger, the M Series (6220) correlated DIO feature doesn't help. Luckily, the 6733 also has the feature. I've attached a vi that shows how to set up the 6733 to output a companion digital waveform to the analog waveform. The first point in the digital waveform is a 1, the rest is 0. You will have to connect a physical wire from the digital line used to an input (PFI) of the 6220.
If you can run the 6220 in a 'batch' mode (a series of finite tasks), you can use this digital line as a Start Trigger for your 6220. If your passes happen too quickly, you might need to run the 6220 continuously. Now, you might use a counter on the 6220 to generated the sample clock for the analog input task. The digital line from the 6733 would serve as the counter tasks's Start Trigger. The counter task would produce a series of pulses each time it got this trigger. This is getting a little complicated.
Attachments:
6733 Correlated AO and DO.vi ‏66 KB

PXI 6220 - problems with the counter

Hello all,
I try to make a buffered counting with counter0 of my PXI card 6220, to count the speed of a motor through a photocell and a sticker over the pulley of the motor.
I have wired my photocell at PFI8 (source) and I generate a pulse train that I have wired in PFI9.
The input to the counter is a pulse train 5V high level - 0V low level.
The problem is that the counter counts sometimes more than 1 pulse for every turn of the motor. However, apparently the pulse train looks ok.
I don´t know what´s the problem.
The rising slope of the pulses looks very nice so, I think I could discard it.
I can suppose that in between pulses there are some glitches at a very high frequency that I cannot see (I have sampled this signal only at 800kHz and at this frequency there are no glitches), but maybe the counter yes, because it works at 20MHz.
Somebody has experienced this problem. Sometimes ago, using a PCI6221, I solved a similar problem by activating the digital filtering, but it seems it is not possible to activate for this cards. Could somebody confirm it?
Any ideas will be appreciated.
Thank you very much in advance!!

Pete;
I agree that is a little strange.We don't have such problem reported on our Data Bases.
A workaround you can try is to make a sinle pulse goes to the source, before start the buffered acquisition, and see if that makes the counter keeps reporting a 1 value.
You can also try the same thing on another counter of the board to see if that problem is related to the counter you are using.
Regards
Filipe A.
Applications Engineer
National Instruments

PXI-6220 And Scan List

I want to acquire mutiple singnels with PXI-6620, and I see that a Scan List memory of 4095 entries is indicated in the data sheet. I want to program the Scan List with CVI, and what should I do? I cannot find anything about it in the DAQmx mannul.
Thanks!

Hello,
You can take a look at the examples we have that are included with NI-DAQ. You can find these examples in C:\Program Files\National Instruments\CVI70\samples\DAQmx. You can then program multiple scan lists depending on the application you want to do.
Hope this helps!
LA

PXI 2527 & PXI 4071 -Questions about EMF considerations for high accuracy measurements and EMF calibration schemes?

Hi!
I need to perform an in-depth analysis of the overall system accuracy for a proposed system. I'm well underway using the extensive documentation in the start-menu National Instruments\NI-DMM\ and ..\NI-Switch\ Documenation folders...
While typing the question, I think I partially answered myself while cross-referencing NI documents... However a couple of questions remain:
If I connect a DMM to a 2 by X arranged switch/mux, each DMM probe will see twice the listed internal "Differential thermal EMF" at a typical value of 2.5uV and a max value of less than 12uV (per relay). So the total effect on the DMM uncertainty caused by the switch EMF would be 2*2.5uV = 5uV? Or should these be added as RSS: = sqrt(2.5^2+2.5^2) since you can not know if the two relays have the same emf?
Is there anything that can be done to characterize or account for this EMF (software cal, etc?)?
For example, assuming the following:
* Instruments and standards are powered on for several hours to allow thermal stability inside of the rack and enclosures
* temperature in room outside of rack is constant
Is there a reliable way of measureing/zeroing the effect of system emf? Could this be done by applying a high quality, low emf short at the point where the DUT would normally be located, followed by a series of long-aperture voltage average measurements at the lowest DMM range, where the end result (say (+)8.9....uV) could be taken as a system calibration constant accurate to the spec's of the DMM?
What would the accuracy of the 4071 DMM be, can I calculate it as follows, using 8.9uV +-700.16nV using 90 days and 8.9uV +- 700.16nV + 150nV due to "Additional noise error" assuming integration time of 1 (aperture) for ease of reading the chart, and a multiplier of 15 for the 100mV range. (Is this equivalent to averaging a reading of 1 aperture 100 times?)
So, given the above assumptions, would it be correct to say that I could characterize the system EMF to within 8.5uV+- [700.16nV (DMM cal data) + 0.025ppm*15 (RMS noise, assuming aperture time of 100*100ms = 10s)] = +-[700.16nV+37.5nV] = +- 737.66nV? Or should the ppm accuracy uncertainties be RSS as such: 8.5uV +- sqrt[700.16nV^2 + 37.5nV^2] = 8.5uV +-701.16nV??
As evident by my above line of thought, I am not at all sure how to properly sum the uncertainties (I think you always do RSS for uncertainties from different sources?) and more importantly, how to read and use the graph/table in the NI 4071 Specifications.pdf on page 3. What exactly does it entail to have an integration time larger than 1? Should I adjust the aperture time or would it be more accurate to just leave aperture at default (100ms for current range) and just average multiple readings, say average 10 to get a 10x aperture equivalent?
The below text includes what was going to be the post until I think I answered myself. I left it in as it is relevant to the problem above and includes what I hope to be correct statements. If you are tired of reading now, just stop, if you are bored, feel free to comment on the below section as well.
The problem I have is one of fully understanding part of this documenation. In particular, since a relay consists of (at least) 2 dissimilar metal junctions (as mentioned in the NI Switch help\Fundamentals\General Switching Considerations\Thermal EMF and Offset Voltage section) and because of the thermo-couple effect (Seebeck voltage), it seems that there would be an offset voltage generated inside each of the relays at the point of the junction. It refeers the "Thermocouple Measurements" section (in the same help document) for further details, but this is where my confusion starts to creep up.
In equation (1) it gives the expression for determining E_EMF which for my application is what I care about, I think (see below for details on my application).
What confuses me is this: If my goal is to, as accurately as possible, determine the overall uncertainty in a system consisting of a DMM and a Switch module, do I use the "Differential thermal EMF" as found in the switch data-sheet, or do I need to try and estimate temperatures in the switch and use the equation?
*MY answer to my own question:
By carefully re-reading the example in the thermocouple section of the switch, I realized that they calculate 2 EMF's, one for the internal switch, calculated as 2.5uV (given in the spec sheet of the switch as the typical value) and one for the actual thermocouple. I say actual, because I think my initial confusion stems from the fact that the documenation talks about the relay/switch junctions as thermocouples in one section, and then talks about an external "probe" thermocouple in the next and I got them confused.
As such, if I can ensure low temperatures inside the switch at the location of the junctions (by adequate ventilation and powering down latching relays), I should be able to use 2.5uV as my EMF from the switch module, or to be conservative, <12uV max (from data sheet of 2527 again).
I guess now I have a hard time believeing the 2.5uV typical value listed.. They say the junctions in the relays are typically an iron-nickel alloy against a copper-alloy. Well, those combinations are not explicitly listed in the documenation table for Seebeck coefficients, but even a very small value, like 0.3uV/C adds up to 7.5uV at 25degC. I'm thinking maybe the table values in the NI documentation reffers to the Seebeck values at 25C?
Project Engineer
LabVIEW 2009
Run LabVIEW on WinXP and Vista system.
Used LabVIEW since May 2005
Certifications: CLD and CPI certified
Currently employed.

Seebeck EMV needs temperature gradients , in your relays you hopefully have low temperature gradients ... however in a switching contact you can have all kind diffusions and 'funny' effects, keeping them on same temperature is the best you can do.
Since you work with a multiplexer and with TCs, you need a good Cold junction ( for serious calibrations at 0°C ) and there is the good place for your short cut to measure the zero EMV. Another good test is loop the 'hot junction' back to the cold junction and observe the residual EMV. Touching (or heating/cooling) the TC loop gives another number for the uncertainty calculation: the inhomogeneous material of the TC itself..
A good source for TC knowledge:
Manual on the use of thermocouples in temperature measurement,
ASTM PCN: 28-012093-40,
ISBN 0-8031-1466-4
(Page1): 'Regardless
of how many facts are presented herein and regardless of the percentage
retained,
all will be for naught unless one simple important fact is
kept firmly in mind.
The thermocouple reports only what it "feels."
This may or may not the temperature of interest'
Message Edited by Henrik Volkers on 04-27-2009 09:36 AM
Greetings from Germany
Henrik
LV since v3.1
“ground” is a convenient fantasy
'˙˙˙˙uıɐƃɐ lɐıp puɐ °06 ǝuoɥd ɹnoʎ uɹnʇ ǝsɐǝld 'ʎɹɐuıƃɐɯı sı pǝlɐıp ǝʌɐɥ noʎ ɹǝqɯnu ǝɥʇ'

PXI-6115 & PXI-6143 on Same Computer, RDA's Future

Today I installed several PXI-6115 cards and realized that they are only
supported with traditional DAQ under version 7.2. This is OK for now
because I'm already limited to traditional DAQ to be able to use RDA.
However, I was considering adding the new inexpensive S board, the PXI-6143,
to my system. According to the list of supported boards this board is only
supported by DAQmx. Questions:
1. How can these two S boards be used by the same system if programming with
LabVIEW?
2. Any guesstimate on if or when the PXI-6115 will be supported by DAQmx?
3. Any guesstimate on if or when RDA will be supported by DAQmx? RDA
(remote data acquisition) is an extremely valuable DAQ method and I hope it
will be supported by D
AQmx soon!

Hello,
You are correct about the support of both boards. The 6143 is only supported in DAQmx, and the 6115 is only supported in Traditional DAQ. Here is the best that I can do for the other questions.
1. You can program each card in a different driver. This is not a problem at all. The only conflict occurs when you try and program a card in both drivers at the same time. Such as trying to do analog output in Traditional DAQ and analog input in DAQmx.
2. This is internal information only. For further information I would contact your local sales representative, she/he might be able to assist you further.
3. Again, if and when is internal information. It is not currently supported. At the moment, you can use remote front panels, or create y
our own server/client VIs to control a remote DAQ board.
These are excellent pieces of feedback for our R&D department. I highly encourage anyone who reads this thread to submit product feedback using this link.
Best regards,
Justin T.
National Instruments

Bluetooth connectivity for PXIe-1071, PXIe-8133

Hi, There are about 24 numbers of NI PXIe-1071 chassis with PXIe-8133 controllers in our lab. I would like to interface a Bluetooth device (EEG and ECG monitors) with the DAQ. The DAQs are running Windows 7 and LabVIEW.
How would you suggest I connect the Bluetooth devices to the DAQs?
If I buy Bluetooth dongles that fit via the USB is that a good solution?
Thanks.
Philip

Hi PKP,
Since your controllers are running Windows 7, they function just as a normal computer would; therefore the USB ports would behave just as a desktop would. You could load the drivers onto the controller and collect data from the bluetooth device that way. Do you have software to read the EEG and ECG signals into LabVIEW?
Best,
tannerite
Tannerite
National Instruments

I got Internal Software Error -223044 with my PXI-4472, PXI-1033 and NI expresscard-8360 DaqMx 8.8

When i running the self test of the board in MAX i got error -223044, anyone that has some ideas??
STALT

Hey Stalt,
This particular internal error begs me ask a few questions.
1) Has this 4472 ever been used with DAQmx?
2) How old is this 4472? When was it bought from NI? Can you give me the revision letter of the board? That is found by looking for a number printed on the board that usually begins with "ASSY", then there are several other numbers/letters, but the one letter I care about is the letter right before the "-" So it would look like ASSY11111111E-01 so the revision would be "E"
3) Do you have another PXI system (with DAQmx) that you can initialize this 4472 in?
Let me know
-gaving
Software Engineer
National Instruments

Using PXI-5431and PXI-1411 to test MPEG-2 encoder/decoder

I am looking into a way to test an MPEG-2 encoder/decoder. I have found the PXI-5431, that can generate a NTSC signal which is what I need and the PXI-1411. So, I guess my question is: would this be a good set up to use the 5431 to generate a signal and the 1411 to acquire the signal and do some comparisons to the two. Has anyone done this type of testing? What type of comparisons could be done to the two video signals to verify signal quality(I know very little about video signals)? Or maybe acquire using the PXI-5122?
Thanks,
Brian

Hi BrianPack,
I have some questions. Please be much more detailed and specific in your next response. Try not to use pronouns. Instead, every time you want to use the word "it" or "card", instead use the proper names, such as the "PXI-5122".
What card are you referring to in your first sentence?
When you say (it) "can be configured to decode and encoded MPEG video", do you mean to say you are attempting to encode analog video?
With all the MPEG encoding and decoding, which cards are you referring to? Your two cards, or two NI modules?
When you generate into the encoder, are you wanting to generate from the NI 5431? If this is true, what video standard are you wanting to use?
The Frequency Response, Video Resolution, SNR, and composite signal amplitude measurements should be available with the NI 5122 and MicroLEX VideoMaster. I'm not sure about the NI 1411 because I only support NI's Modular Instruments, but here are the specification sheets for VideoMaster:
http://www.microlex.dk/products/video/videomaster-component.pdf
If you want more information on the NI 1411, it would be best to post a message on the IMAQ/Vision forum. For now, please respond with more specific information and I'll be happy to assist you!
Chad Erickson
Applications Engineer

Can i use PXIe-1073 with an embedded PXIe controller PXIe-8108

I have a PXI express chassis PXIe-1073 with an integrated controller MXI-Express controller PCIe-8361. I now want to use the chassis as a standalone system with an embedded controller.
(a)Can i use PXIe-1073 chassis with PXIe-8108 embedded controller
(b)Can i use a windows based laptop to control the PXIe-1073 via the PCIe-8361 integrated controller.

Hello kanad,
The PXIe-1073 is a MXI-integrate chassis. This means that the MXI card that would normally go into the controller slot (slot 1) is built into the chassis. The PCIe-8361 or Expresscard8360 are placed into the desktop or laptop, respectively, and connect to the chassis. The cards in the PXIe-1073 then appear as if they are part of the desktop of laptop.
Since the controller is built into the chassis, the PXIe-1073 does not have a slot 1. Controllers, such as the 8108 can only be plugged into slot 1. Therefore, the PXIe-1073 can only be controlled by the desktop or laptop MXI link. It cannot run standalone with an embedded controller.
Consider reading page 1-3 and 1-6 in the manual below:
NI PXIe-1073 User Manual and Specifications
Regards,
George T.
Applications Engineering Specialist
National Instruments UK and Ireland

Pushing the limits of continuous high-speed DAQ + processing, with PXI-6115 + PXI-8360

Hi all,
I'm trying to do continuous high-speed data acquisition + processing. I currently have:
Chassis: PXI-1042Q
AI card: PXI-6115 (x2)
Link: PXI-8360
PC CPU: Intel Xeon W3503 (dual-core, 2.40 GHz)
RAM: 4 GB
The idea is to continuously grab 8 channels' worth of analog inputs, scan for "events", and if found, log the events to disk.
My client would like to use the maximum sample rate of 10 MHz, but I found that above 5 MHz, DAQmx Read.vi can no longer keep up (e.g. at 6 MHz, it takes 110 ms to read 100 ms' worth of data).
Im thinking of getting beefier components, but I'm not sure where the bottleneck is. Here are some thoughts:
1) The MXI Express link
The PXI-8360 is rated for a sustained throughput of 100 MB/s.
I'm not sure how big the data is. PXI-6115's ADC is 12-bit. Does that mean each datum transferred through the MXI cable is 1.5 bytes? Is the data padded? Or is it 8 bytes per datum, because Dbls are being transferred?
2) The CPU
In Resource Monitor, I notice that the CPU usage is 0% at 60 kHz, 8% at 61 kHz, and 50% at 70 kHz (meaning that one core is maxed out). I'm surprised that it keeps up all the way until 5 MHz though.
What causes this high CPU usage? Is it due to the conversion of the data into 1D array of waveforms?
3) Something else?
Have I missed something completely? Is what I'm describing even possible?
Thanks in advance for any advice!

Hello,
Each sample will take up 2 bytes, 12 bits data + 4 empty bits. so the PXI-PCI 8360 is only able to transfer a maximum of 50S/s in this case.
Also, because the PXI bus is shared among all of the cards, two PXI 6115 cards will be trying to transfer 80MS/s or 160MB/s.
Finally, since the PXI 6115 are DAQ family cards, their specifications aren't really written for continuous data acquisition at the upper end of their sample rate, but I'm interested to know if you can get up to 10MS/s with only one card operating at a time?
-Jim B
Applications Engineer, National Instruments
CLD, CTD

CTR works with PXI 8196,PXIe 8102, fails with PXIe 8100 - why?

My client has reported a problem.
For years he has used a PXI 8196 RT Controller with PXI 6602 Counter card and my software has given good results. They have 20+ of these systems and they have worked well.
Now they are moving to PXIe 810x controllers, for cost reasons.
WIth a PXIe 8102, the same code also works perfectly, measuring total counts over a period, as well as instantaneous frequency.
With a PXIe 8100 - the exact same code reports DIFFERENT answers. The reported frequency is always 1% HIGHER than actual (For example, a known 4500 Hz input is reported as 4500 Hz on 8102, but as 4545 Hz on 8100.
This happens on any channel, and swapping just the controller will make the problem come and go.
Here is the CONFIGURE code, where the channels are set up (again, this has worked for years).
Here is the SAMPLE code:
Basically the CONFIG code configures the thing to count edges. I do this because they need an accurate count over a 20-minute period, in addition to instantaneous frequency readings.
The AVG TIME is a user-settable number defining how long a period to average, when showing the "instantaneous" frequency.
So, I create a buffer for N samples, corresponding to that period.
At SAMPLE time, I read the counter. I replace the oldest value in the buffer with the newest, then subtract the newest - oldest to get the total counts in the sample period.
The PULSES PER COUNT item is a scaler, to account for a 60-tooth wheel, or something.
So, this same code has worked perfectly for years, until I plug an 8100 code in. Then the result changes by 1 %, and EXACTLY 1%?
The CPU burden on the bad controller is 31%.
Any ideas?
Steve Bird
Culverson Software - Elegant software that is a pleasure to use.
Culverson.com
Blog for (mostly LabVIEW) programmers: Tips And Tricks

Well, the controllers are not in my own hands. I have an 8196 controller and on that, the CPU time is between 2 and 4%.
But the 8100 and 8102 controllers are in my client's hands.
I haven't gotten any hard timing numbers other than I saw the 31% figure reported on the video monitor.
It's hard to believe that it would be EXACTLY 1% if it was CPU overburden.
My software includes a calibration facility; here is a run from the good 8102:
Here is a run from the 8100:
This was with a reference digital freq generator. You can see the one case where everything is within 0.1 Hz.
the other case has everything EXACTLY 1% higher. My only explanation is that the scan engine is running 1% slower.
Steve Bird
Culverson Software - Elegant software that is a pleasure to use.
Culverson.com
Blog for (mostly LabVIEW) programmers: Tips And Tricks

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