Connect alarm event to an analog output

Hi,
I work on a LabView 5.1 Industrial Supervision System. I would like to
connect an alarm event (limit alert high and/or low) to an analog
output. The problem is that the system is very locked. I can't add
some Vi's. There is in some alarm configuration (for example in "Alarm
Setup.vi") the possiblity to do this connection.
Thanks
Nicolas Hrycenko

Nicolas,
I am not exactly sure what you are asking. It should be fairly easy to check to see if a value is greater that some level, and if so toggle an alarm. Are you asking for ideas on how to do this, or are you trying to modify a VI (Alarm Setup VI) and not able to? I have never heard of that VI, so I assume it is not built into LabVIEW. Give us a little deeper idea of what you are trying to do, and I am sure we can help you out.

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OPC Alarm Event server connectivity?

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Can Lookout connect to OPC Alarm / Event servers? It is very important for me that I can do this.
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Many thanks,
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Hi Ryan,
Thanks for your response. Is there a political or technical reason for this?
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Why does analog output max out at only 2 V when I connect my device?

I have a device that works on LabVIEW 6 (Win-NT machine), switching over to Vista, LabVIEW2009, with PCIe-6323. the voltage output signal control works fine on the NT machine over the full range of 0-10V. On the LabVIEW 2009/Vista machine, open AO channels work properly from -10 to 10 V in MAX. But when I connect the device - the same device that works just fine on LabVIEW6 - It only works up to ~2V. For example - I enter 1.5 V - i read 1.5 V. I anything from 2.2-10V, and I get 2.2 V. If I disconnect the device, I get output voltage that I enter in the Task test panel.
How can I get it to run the full -10 to 10 V?

The way that the scaling works for DAQmx tasks changed somewhere between DAQmx 7.? and DAQmx 8.8.
At least it did for analog inputs anyway.
Check if any scale is applied to your analog output task. Try changing it.
Troy
CLDEach snowflake in an avalanche pleads not guilty. - Stanislaw J. Lec
I haven't failed, I've found 10,000 ways that don't work - Thomas Edison
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Alarm & Event Query To Spreadsheet.vi

dear all,
i m using "Alarm & Event Query To Spreadsheet.vi" for alarm transfer using following inputs
1. Filter
2.Display Format
3. Output file path(C:\Program Files\National Instruments\LabVIEW 7.1\*.ALR)
and Database URL it will take by default i.e current tagfile.scf
on running this i get following error
"HIST_AlarmsToSpreadsheet.vi, Citadel: (Hex 0x8ABC1008) Read alarm failed because of connection or query failure."
if i give the database URL manually in the following way
\\computer name\Labview
then i get the following error out
"HIST_AlarmsToSpreadsheet.vi, IAK_SHARED: (Hex 0x8ABC700A) Not found."
so pls solve my problem as early as possible for u
thanks and regards,
dhanwanti

Hi dhanwanti,
There could be a couple possibilities here -- one is that the database you are trying to reference has become disconnected -- Make sure you can see historical data in MAX. If needed, reconnect your database or create a new one and change this in the .scf file in the Tag Configuration Editor.
Another possibility is that some of the parameters you have set in the filtering could be incorrect such as start and stop time. I would suggest creating a simple test VI to make sure you can get the Alarm & Event Query To Spreadsheet.vi working, and then double check how it integrates into your project. You may also want to take a look at the example that ships with the DSC Module for this VI, found in the Example Finder under Toolkits and Modules » Datalogging and Supervisory Control » Alarms and Events » Export Alarms to File.VI.
Doug M
Applications Engineer
National Instruments
For those unfamiliar with NBC's The Office, my icon is NOT a picture of me

Usb-6009 analog output voltage

Hi,
The usb-6009 has two 0-5 volts analog ouputs. Is it possible to connect
them in series, in order to get a single 0-10 volts analog output
channel ?
Thanks,
Nicolas

Those are ground-referenced signals. To connect them in series, you would have to connect one of the outputs to ground. You would be shorting out (at least) one of your analog outputs, and probably damage the unit.
John Weeks
WaveMetrics, Inc.
Phone (503) 620-3001
Fax (503) 620-6754
www.wavemetrics.com

Single shot analog output: How to pulse this. Probably easy, I'm at a loss.

Hello.
I have a piece of machinery that my system is connected to. Every time it reaches a proximity sensor (It's a reciprocating unit), I need to do a single pulse of 5v out of my analog output. It has to be fast, it has to stop until the sensor is reached again, and it can't stay 'on' for long.
I've attached my VI. I'm using a voltage input via DAQ assistant, routed through some logic to produce a 'true' boolean every time that sensor is reached, and that boolean is connected to a case structure with voltage out tasks created in DAQmx.
My problem is that the machine won't reverse while the case is still true and there's still the 5v being called by the true case on the case structure. It has to pulse, then stop, then be allowed to come back when the proximity sensor is reached again. As it is now, the machine reaches the prox and then the whole system stops, as the 'true' condition on the case structure, and subsequent voltage output, remain high.
I've attached the VI and heirarchy as well.
I've tried a few different things here, as well as just using a DAQ assistant with N samples, but that would just retrigger when the loop repeats anyway.
I'd love to sit and bang my head against this til I get it, but I'm under a time constraint. Help!
Still confused after 8 years.
Solved!
Go to Solution.
Attachments:
using create channel.vi ‏94 KB
logicsub.vi ‏32 KB

Ralph, without knowing the exact DAQ card that you are using, it is difficult to give you the best solution. If you want to continue with the solution that you currently have, try adding a shift register to the outer while loop to track the previous value of the boolean. In this way, we can keep multiple values that are above the threshold from causing multiple pulses. Next add a time delay after the DAQmx Write, then add another DAQmx Write to set the output back to your low value. Remove all code from your "false" case. See attached VIs. Please let us know what model of DAQ card you have as we may be able to do something clever like a retriggerable pulse train if your card can support it.
Charles Chickering
Charles Chickering
Architecture is art with rules.
...and the rules are more like guidelines
Attachments:
using create channel.vi ‏98 KB
logicsub.vi ‏29 KB

How to send an analog output signal on same axis running a stepping motor umi 7764/ PCI7334

I am running a single axis stepping motor (which is working fine) but
for the application I need to be able to turn on and off a 5 volt
laser. It notes in the manual for the UMI 7764 that the the
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would like to use it as such, but can't figure out what VI's actually
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Ideally I would use the analog output on the same axis that the
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if this isn't possible (ie. it may not be possible to step and send
analog voltage output on same axis at same time). I have been
looking at the configuring DAQ and ADC stuff, but can't seem to make
sense if these actually control the analog output channel. I
think they just control the Analog input channels, but maybe I am
wrong.
Any help would be greatly appreciated
Andre

Hi,
It is possible to send analog output out of the same same DAC channel in which your stepper is connected, if you configure the stepper as open loop in MAX. I've tried it. This way you have the stepper output, analog output and encoder input acting independently. So you can use these seperately for different purposes, such as using the analog output for constant speed motors where speed or position control is not of much importance, encoder for positioning some other axes and stepper output for stepper control. With good programming skills, the NI motion controllers can thus be used for the most complex configurations. Great work NI !!! Nothing is impossible.
Regards,
Giridhar Rajan
Automation Engineer, Design
Cruiser Controls
Mumbai, India

PICe-6259 with DasyLAB 9 - How to do Analog Output

Hi,
I'm trying to get a small project working in DasyLAB 9.0.2 and I need some serious help.
I'm working with a PCIe-6259 and NiDAQmx 8 is installed. I simply want to create a program that uses a slider to adjust the analog output on 4 channels and read the slider value on a meter. This is a fresh installation of DasyLAB.
Here's the program that I setup and the errors that I get.
I select: Modules -> Input/Output -> NIDAQ -> Analog Output.
I adjust the properties of the DAC module to include channels 0,1,2,3 and select OK. (I don't adjust any of the other properties)
I then select: Modules -> Control -> Slider
I adjust the properties of the slider to include the same channels as above.
I then select: Modules -> Display -> Analog Meter
I adjust the properties of the meter to include the same channes.
The meters and Analog output are wired in parallel.
I get the following errors:
NI-DAQmx: Error Message
Driver: Task DA00, Version: 0.15
Possibly Reason:
-> The module can process the number of "values to be written".
File: ProcessData_KONTINUIERLICH.H, Line: 39
When I press OK I get:
NI-DAQmx: Error Message
Driver: Task DA00, Version: 0.15
Possibly Reason:
-> The driver does not use all NI-DAQmx task channel names. This is not valid, reconfigure the module to use all task channels.
Note: A NI-DAQmx task for analog / digital / frequency output must not have more than 16 channels. If you need more than 16 channels for the output, you must use more NI-DAQmx tasks.
File: MODUL_DA.C, Line: 2131
Any help to point me in the right direction would be greatly appreciated.
The next part of my program will include acquiring data from the analog channels, but I need to get the AO working first. I've run into some issues with Analog Input as well, but I thought I should start with AO first.
Thanks in advance!
Chris

Here's what I did using the NI-DAQmx simulation mode:
    - create two tasks
            Analog Output - 4 channels, 1k output rate, 100 samples to write, Continuous
          Analog Input - 4 channels, 1k input rate, 100 samples to read, Continuous
    Save them. Start up or synchronize DASYLab (Under Measurement Boards Settings - NI-DAQmx - Synchronize with... in earlier versions, it's under Hardware Setup)
    - Create Slider. Open Slider properties, click on Options, Synchronize to the AO task that you created. This step is really important - it ensures that the data rate matches what NI-DAQmx is expecting.
    - Connect Slider to NI-DAQmx AO module, configured for 4 channels.
    - Create AI module. Connect to the AI task that you created.
    Press Start. It should run. I can't verify absolute accuracy in simulation mode, but, I received no errors.
    Your first error is probably the result of the timing being wrong - the Slider defaults to the "Driver" timebase. The rest of the errors seem to be a cascade off the first.
    Note - my simulation did not work without the Analog Input. It generated no data. That may be an artifact of the simulator, but, once I put an Analog Input on the worksheet, it ran okay.
    I hope this helps.
- cj
Measurement Computing (MCC) has free technical support. Visit www.mccdaq.com and click on the "Support" tab for all support options, including DASYLab.

Is any extra isolation required when using Analog output to dirve higer power circuitry?

I want to connect the analog output of a DAQcard-1200 to a current amplifier to give 5A and a tranformer to give approx 200V, is any extra isolation required to protect the card?

Hello;
As long as the maximum current that the board can source is taken in consideration and the input impedance of the external circuitry is high enough to prevent signal reflections back to the DAQ board, you should be good to go.
However, since the protection circuitry can be built with such little budget, I wouldn't take my chances. I would go ahead and include the protection circuitry anyway.
Regards
Filipe A.
Applications Engineer
National Instruments

Can I use two FP-AO-210's and one FP-1000 to obtain 16 channels of analog output?

Hello All,
I'm new to both Fieldpoint and LabVIEW.
I'm developing a control system that requires at least 9 channels of analog-only output. I have been trying to connect two FP-AO-210's to a single FP-1000 by connecting one FP-AO-210 directly to the FP-1000, and the second FP-AO-210 to the first FP-AO-210. However, Fieldpoint Explorer only detects the network interface and the first analog output module.
Is this configuration correct? Or, do I need a FP-1001 in order to use a second FP-AO-210?
Does anyone have any alternate suggestions on how to obtain at least 9 channels of analog output?
Thanks,
Eric W

Eric,
One FP-1000 (or FP-1001/160X/20XX) can control up to 9 IO modules. If the second FP-AO-210 is not being detected by FieldPoint Explorer there are a couple things to check. First check to make sure that all of the terminal bases and modules are firmly connected to each other.
Next, check the Power & Ready LED of the FP-AO-210 at address 2. Both LEDs should be lit. If they are not, de-power the system, remove the modules and terminal bases and make sure that you do not have any bent pins. Re-assemble and power up the system. Use FieldPoint Explorer again.
If the module is still not detected, take a look at the addressing of the detected modules. The system should be detecting the first FP-AO-210 at address 1 (or 1 + a multiple of 10 if you have s
et the FP-1000 to a different address). If the FP-AO-210 is at a different address, then it is likely a problem with the addressing circuitry either in the network module or the terminal base. Try swapping the positions of the two terminal bases and try again. If it works, then the error is in the addressing circuitry of the terminal base, if not, then it is in the addressing circuitry of the network module. Note: bent pins can also cause this.
Regards,
Aaron

High Noise on Analog Output PCI 6289

Hi guys
I am using a PCI 6289 M series device for A/D characterization , I am using the device both for the analog output generation and also for data acquistion of the digital lines , The dynamic tests for the A/D were showing a very poor SNR ratio of the ADC, it is a 12 bit adc so technically in the ideal case i should atleast see 90 db but the resulting figure was way lower around 40 db .
I connected the A0 from the PCI 6289 brought out to a scb-68 block to a RHODE and SCHWARZ spectrum analyzer , the above spectrum analyzer is a decent one with good analysis capability and I was surprised to see a SNR of 50 db , the data sheet says that PCI 628X devices have a internal 16 bit DAC so technically the SNR should be atleast 90 db even if 6 db were removed for the harsh environment of the computer .
please advise , have anybody else faced this problem , the data sheet does not give a figure for the SNR ratio of the card , since i need to test a 12 bit adc , thought that 6289 would be up to the task since it has a 16 bit DAC.I am using the Noise shielding cables and also SCB-68 block , the block is far removed from other power supplies .
any ideas why the noise is occuring , one of my colleagues says maybe the harsh environment inside the pc enclosure causes it , is it necessary to use a separate PCI box for the card and then connect the card to the computer , is this standard procedure ?????.
and also does the PCI -6289 have a filtering option for the analog output , all i could find was the filtering for input.

Hi Tom
Thanks a lot for responding to the thread , did not expect a response in the holiday season . The SNR for the 12 bit one was a typo , was referring to the 16 bit onboard dac in the M series card , which technically should ensure a clean input signal having atleast 90 db .
The info you have given helps a lot , i suspect the conditions inside the pc might be causing it , also i am driving the analog output from the card at almost its limits of 2.5 MS/s , the sample rate specification for the card on the data sheet says 2.8 MS/s , also i notice the settling time requirement for the outputs is 3 us which i suspect will put the onboard DAC under quite a load.
If the conditions inside the PC cannot be rectified , where can i find a external PCI box which can be connected to the computer or does such a box exist only for the PXI cards ? will that necessarily rectify the problem and also since filtering is not possible on the card itself , I remember reading the scb -68 connector block has single RC output filter option , i would have to use discrete R,C components to make it but notice on the right hand corner some pcb holes are provided , would this help.
Would appreciate your Response
Thank you
Chip learner

How can i deliver a single pulse of varying amplitude using Analog output and USB-6251?

I am trying to generate an analog output for the following waveform:
Pulse width: 300 usec, Frequency 40 Hz, Amplitude is following a sine wave with a 2 second period.
My approach is: Use an async timer with 1/[40 Hz] sec interval. I set the DAQ output rate at 1 MHz and the approach has been to generate and write 300 samples of the amplitude I need to send out, then wait for the next async interval callback , update amplitude etc etc. The assumption is that once the 300 samples are written and the task started , a 300 usec pulse would be sent out , task then stopped and then the analog output would be set to 0 waiting for he next pulse. The reality is that I get a stream of pulses of 300 usec which last the whole timer interval.
So , trying to establish whether what I am trying to do is feasible without actually sending a large array to the USB-6251 which would write zeros for the period after 300 usec.
Here is my timercallback code for review:
    switch (event)
        case EVENT_TIMER_TICK:
            DAQmxErrChk(DAQmxStopTask(TaskAnalog));
Determine Voltage value algorithm here
           //Generate Waveform and start Task
           //Prepare AO arr
           for (k=0;k<300;k++)
               AOArr[k] = 0;
               if (k<G_PulseWidth)
               AOArr[k] = VOLTAGE_OUTPUT;
           if (AOArr!=NULL)
               DAQmxErrChk(DAQmxWriteAnalogF64 (TaskAnalog, (int32) 300 , 0, DAQmx_Val_WaitInfinitely, DAQmx_Val_GroupByChannel , AOArr, &sampsPerChanWritten, NULL));
            DAQmxErrChk(DAQmxStartTask(TaskAnalog));
           break;
Thanks

I did resovle the issue I encountered. It was due to bad configuration of the Task.
My initial configuration was:
DAQmxErrChk(DAQmxCfgSampClkTiming(TaskAnalog, "",1.0E+06, DAQmx_Val_Rising, DAQmx_Val_FiniteSamps , 300 * 1.0E+06));
which should be:
DAQmxErrChk(DAQmxCfgSampClkTiming(TaskAnalog, "",1.0E+06, DAQmx_Val_Rising, DAQmx_Val_FiniteSamps , 300));
THis did it. works very well.
THanks

How to reset buffer pointer for analog output generation?

I am doing a finite analog output generation on a USB-6216
Sequence of events:
DAQmx Create Task
DAQmx Timing (finite samples, 1000Hz)
Use DAQmx timing property SampQuantamples per channel to set buffer size
Write buffer with DAQmx Write
Repeat
DAQmx Start Task
DAQmx Wait until done
DAQmx Stop Task
Until finished
DAQmx Clear Task
I get a full waveform output on the first iteration of the loop. On subsequent iterations I get only a small section of the waveform, but no error. It seems that it is regenerating the waveform, because when I switch off regeneration I get an error at Start Task, but before it can regenerate all the data Wait Until Done.vi decides that the generation is done and exits, stopping the generation.
I have done this with a PCI device and it works fine; every call to Start Task generates the whole waveform again.
OK, so it looks like after every waveform generation completes I need to reset the pointer to the start of the buffer, so that the Wait Until Done vi does not think the generation is done. Or - maybe there is a way to reset the "Generation Done" state?
I'm sure there's an easy way to do this....?

Hi CDancer,
Many thanks for contacting National Instruments. If I can start by giving some general advice, it would be well worth posting your actual VI. This helps others on this forum in helping you with your application.
From the sounds of things, you want to do continuous analog output generation. I have had a look at the examples that come with LabVIEW and I think you should look at the one below.
I would have a look at some of the DAQmx examples that come installed with LabVIEW. The following example would be particularly relevant I feel
Cont Gen Voltage Wfm-Int Clk-non Regeneration.vi
Please let me know how you get on.
Many thanks,
Andrew McLennan
Applications Engineer
National Instruments

CITADEL and RELATIONAL DATABASE Alarms & Events Logging Time Resolution

Hello,
I would like to know how I can setup Logging Time Resolution when Logging Alarms & Events to CITADEL or RELATIONAL DATABASE.
I tried use Logging:Time Resolution Property of Class: Variable Properties without success.
In my application I need that timestamp of SetTime, AckTime and ClearTime will be logged using Second Time Resolution, in other words, with fractional seconds part zero.
I am using a Event Structure to get SetTime, AckTime and ClearTime events and I want to UPDATE Area and Ack Comment Fields thru Database Connectivity but when I use SetTime timestamp supplied by Event Structure in WHERE clause Its not possible get the right alarm record because there are a different time resolution between LV SetTime timestamp and timestamp value logged in database.
Eduardo Condemarin
Attachments:
Logging Time Resolution.jpg ‏271 KB

I'm configuring the variables to be logged in the same way that appears on the file you send, but it doesn't work... I don't know what else to do.
I'm sending you the configuration image file, the error message image and a simple vi that creates the database; after, values are logged; I generate several values for the variable, values that are above the HI limit of the acceptance value (previously configured) so alarms are generated. When I push the button STOP, the system stops logging values to the database and performs a query to the alarms database, and the corresponding error is generated... (file attached)
The result: With the aid of MAXThe data is logged correctly on the DATA database (I can view the trace), but the alarm generated is not logged on the alarms database created programatically...
The same vi is used but creating another database manually with the aid of MAX and configuring the library to log the alarms to that database.... same result
I try this sabe conditions on three different PCs with the same result, and I try to reinstall LabVIEW (development and DSC) completelly (uff!) and still doesn't work... ¿what else can I do?
I'd appreciate very much your help.
Ignacio
Attachments:
error.jpg ‏56 KB
test_db.vi ‏38 KB
config.jpg ‏150 KB

Reading Alarms/Events Failed. No Alarm History.

Lookout 6.1 build 3. No alarm history within Lookout. When saving alarm data to CSV file, file creates but is empty. Trends and other logged data seem OK.
Measurement & Automation Explorer. No problem connecting to database. New A&E View, Refresh, returns the message "Reading Alarms/Events Failed".

Control Panel->Administrative Tools->Services, restart the service SQL Server(Citadel)
Ryan Shi
National Instruments

Connect alarm event to an analog output

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