Digital output to a different voltage?

Similar Questions

• Output 2 length of time different voltages while recording the current of one of the outputs

  I create a vi that generates output 2 waveforms of voltage different (AO1 and AO2). These signals is different in duration and number of times it will be produced. AO1 must take place several times while AO2 is running her first time. I also record the entry of AI1 output in AO1. I have attached a vi that I thought it would work. I thought it would be good to have the AI/StartTrigger initialize the acquisition and the output voltage. However, this arrangement results in an error. The error I get is-200802. Am I going about this all wrong? Any ideas?

  At first glance, I see some problems with your code:

  -You arecalling DAQmx writing before calling DAQmx Start. The departure must be called before writing.

  -You have two tasks of analog output. Only analog output task is allowed per unit. If both of your analog output channels are on the same card, they must be in the same spot.

  Here is a great resource for getting started with DAQmx programming.

• 6008 daq digital outputs to control relays

  Hi all, I'm looking to help create a VI to send out digital to a daq 6008 to control relays. What I'm trying to do is when you press start and a condition is met send a digital output to control a relay for 30 seconds or so to take a measured voltage to be taken an analog voltage. After 30 seconds, I want the first relay to switch off and the next relay lights for the same amount of time. I want to continue this sequence to 7 readings, blood for every step and send the data to an excel file. I know it's basic stuff, but my experience with labview is limited! Any help would be greatly appreciated.

  Thank you

  Paul

  Hi Paul,.

  I looked on your problem this afternoon and I agree completely Fan Ravens that the state machine is in fact the most appropriate architecture for such a task of data acquisition. A state machine architecture is one of the most commonly used in LabVIEW design patterns and is especially suitable for any program where you have clearly defined the steps that can be represented by the States and rules for the transition between these States.

  There is a model of Machine of State Standard contained in LabVIEW which should give you an idea of the underlying architecture and is a good starting point. To give you a better idea of how this architecture can be applied to a data acquisition task, I would recommend that you look at This example. Although States will be slightly different in your case, this should provide you with a good understanding of how you can architect such a request.

  I hope this helps.

  Best regards

  Christian Hartshorne

  Technical sales engineer

  National Instruments UK

• Synchronization of analog and digital output with the external sample clock

  Hello

  First of all sorry for my English, I will try to explain what I want to do.

  I want my PCIe-6321 to send two custom signals (modification sawtooths) on a mirror controller. I would also like to generate output with my card at the beginning of each tooth of saw. Everything must be synchronized with an external k-clock signal of 100 kHz. The idea is that whenever the PCI receives a trigger to external clock, it sends two analog output voltages and when he received 1024 clock ticks it will also send a pic of triggering TTL. What I do is first prepare the map and after that in a loop sending and modifing the output values of the two signals and at the same time send a digital signal Boolean in each arch, so when's done it 1024 iterations of the loop I send an event to the digital port. Attached you can see.

  The problem is that I don't know how to synchronize both. Can I use the sample clock just to the analog output? I can use sample for the two outputs clock, or do I need to use the output of the meter? If don't know how to use it here.

  If I do nothing else bad/wrong, I would be grateful for feedback.

  Thanks in advance,
  Pablo

  I don't know how but I find the solution. I'm generating more than a positive value (as I was triggered maybe very fast the oscilloscope has been absent there). If I put the sample clock of digital output to use the sampling/ao/Dev1 clock that it doesn't, but if I put to use the same source as the OD (terminal where my external clock is connected), but the trigger to start the DO to be Dev1/ao/StartTrigger this works. I don't really know why, but it does.

  Thank you for your patience and your help. I put here the final code.

• separation of two edges using a digital output

  I am using a DAQ, PXI-6229 map and programming in c# .net.

  I'm claiming a falling edge on PFI12 used as a digital output, and I need to measure the time between this edge and a second front on PFI8 used as a digital input.  I have implemented the code using some examples I found.  I don't know when to to argue the signal on PFI12 in order to be read at the right time.  Playback must be put in place before the signal is asserted, but I do not know how to set it up it up properly.

  Here is the code I have so far:

  Public Sub MeasureAcquisitionTime()
  {
  DigitalSingleInputTask = new Task();
  CIChannel counterSetup;
  firstEdge = CITwoEdgeSeparationFirstEdge.Falling;
  secondEdge = CITwoEdgeSeparationSecondEdge.Rising;
  Double minTime = 10-3;
  Double maxTime = 60F-3;
  String auxCounterInput = "/" + CardName + ' / PFI12 ';
  String gateCounterInput = "/" + CardName + ' / PFI8 ';
              
  counterSetup = DigitalSingleInputTask.CIChannels.CreateTwoEdgeSeparationChannel)
  CardName + ' / ctr1 ', 'counter',
  minTime,
  maxTime,
  firstEdge, secondEdge, CITwoEdgeSeparationUnits.Seconds);
  counterSetup.TwoEdgeSeparationFirstTerminal = auxCounterInput;
  counterSetup.TwoEdgeSeparationSecondTerminal = gateCounterInput;
  DigitalSingleInputTask.Control (TaskAction.Verify);
  runningDigitalTask = DigitalSingleInputTask;
  counterInReader = new CounterReader (DigitalSingleInputTask.Stream);
  Double data = counterInReader.ReadSingleSampleDouble ();
  }

  I'm glad to hear it.

  paofthree wrote:

  Is there a way to make a measure of separation of two edges on the analog inputs of the PXI-6229?

  The only way would be to constantly acquire the analog input voltage and calculate the separation of the two edges in the software.

  Best regards

• NI 9474 digital output

  Hello

  I am trying to learn labVIEW DAQ and right now I'm trying to understand how to use NI 9474 with labview. NEITHER 9474 is a device with digital outputs. I am attaching a (badly drawn) diagram of how I have my real wired circuit. For some reason, the voltage at the terminals of the resistance is 9v instead what that either the digital output should be when I put assistant daq for 1 sample on request. When I change to continuous samples daq assistant, it reads 4.6v. So I wonder what am I doing wrong and what should my digital output be?

  I've attached my vi file, if someone can you please help me understand how to use NI 9474 with labview?

  
  

• analog sync of input with the onset of the digital output

  I'm trying out an analog signal to a file with a specified frequency samples.  I also need a digital output to trigger a measurement at a frequency specified on a separate system.  The frequency is controlled by the loop exits and timed when the iteration number divided by the period is exactly a whole number.

  Both outputs work.  The problem is that they are not synchronized.  The analog output amounts to about 0.5 ms faster than the digital signal.  (I checked with an oscilloscope)  They both start in the 1 ms each loop runs for, but I really need them to start at the same instant.  What can I do to synchronize?  Also, if I'm going in the wrong direction complete, please indicate.

  I use a card PCI-6723, which I think someone at some point, said not having a material sample clock.  That's why I try to use a timed software loop.

  Hi NEA.

  You must use the 6723's built-in calendar to accomplish what you want.  As the digital output subsystem is only clocked by the software, an appropriate solution should be to use one of the counters to the pulse output.

  The attached code should show how.  You can use the counter to output a pulse all samples of the AO N task.  Material requires the initial delay to have a minimum of 2 ticks, so the meter will be behind the task of the AO by 2 samples in this case.  There are different ways to work around this problem if you need (for example write two samples of 0 first).

  Best regards

• Problem with a digital output in the information of an analog input

  Hello

  I use a SCXI-1000DC module with a module of the SCXI-1600, SCXI-1531 module and SCXI-1163 module to receive an analog of an accelerometer signal and a digital signal.
  I claim that the accelerometer is constantly monitored, and the output is on when I want to, by an impulse that I comand in labview.
  I use a rate 25 k and a 12, 5K samples per channel on DAQmx Timing.

  I notice in DAQmx read, if I put a sample of hight by channel, the output is not there when I want to, and if I put a few samples per channel, I exit when I want to, but the program seems to be slow with the passage of time. I don't know how I can solve this problem!

  I'm sorry for my English, and I hope you can help me.

  Thank you

  Silvia

  Hello Silvia,.

  If you ask a larger number of samples, the labview diagram will stay longer in the DAQmx Read function, so the while loop runs slowly, and the digital output is updated less often.

  I suggest that you use 2 separate while loops: one for the analog input and the other for digital output, so that each loop might run at a different speed.

  Best regards

• How to quit smoking all the void s vi before resetting digital outputs and then closing

  I have a project that contains a main VI called home screen that calls many different sub vi. I am monitoring for a press of physical button by a digital input with a DAQ Assistant on the main VI and in this case I want my program to abandon all of its VI running and reset all the digital outputs before the closure of Labview. No idea how I would go all this?

  I have attatched the basic model of what I do.

  Joelspider33 wrote:

  The problem is more to do with some of my money that VI running a DAQ Assistant using the same digital lines like the ones I'm wanting to reset and causing it to throw up an error message.

  This is why you must set the DIO AFTER all subVIs are arrested.  And to do this, you must send messages to these subVIs telling them to stop.  If done correctly, it is a very quick process.

• digital output microsecond LED timer

  Hey all,.

  I'm doing a table of 10 LEDs in a row to form an analog timer to use to characterize the delay of the shutter on a digital SLR. We'll first stage shutter lag on the camera using a method different and well set the delay of the shutter for interior<1ms. i="" am="" trying="" to="" use="" labview="" alongside="" a="" ni="" usb="" 6251="" using="" an="" sc-2345="" for="" access="" to="" the="" digital="" outputs.="" im="" using="" a="" timed="" structure="" and="" a="" timed="" loop="" to="" ensure="" the="" timing="" between="" each="" led="" turning="" on="" corresponds="" to="" an="" actual="" time.="" however,="" i="" am="" not="" getting="" the="" results="" i="" thought="" i="" would.="" the="" timing="" does="" not="" seem="" to="" be="" what="" i="" thought="" it="" would="" be="" and="" i="" can="" not="" get="" the="" timed="" loop="" to="" work="" with="" all="" the="" channels="" at="" the="" desired="" frequency="" which="" would="" idealy="" be="" as="" high="" as="" possible.="" could="" someone="" take="" a="" look="" at="" my="" code="" and="" provide="" me="" with="" some="" insight="" where="" i="" may="" be="" getting="" issues?="" i="" apologize="" if="" i="" am="" overlooking="" important="" information="" that="" may="" be="" needed="" to="" help="" solve="">

  ~ Aaron

  I have no DAQmx I can't be sure.  I think that the 6251 has a maximum rate of 1 MHz in order to try to set the rate to 20 MHz should generate an error.  For the purposes of test on the rate 1 Hz bit or less.  Then you should be able to see the LEDs as turning on and off.

  You may also need to set the number of samples to the size of the array.  Referring to the size of the array fed to Scripture DAQmx, not the table on the front panel.  With the number of samples set to 1, I would expect that he wrote that the first element of the array that is equal to zero.  That does not produce a very interesting performance: he lets just all lights off the coast!

  Lynn

• Digital output is not 5V when connected to a circuit

  I have a very simple circuit I want to operate a valve. I have a NI USB 6008 with 12 digital i/o ports, a KF0602D solid state relay, 12V power and a solenoid valve.

  The idea behind this circuit is pretty simple: use a digital line of the 6008 to close or open the switch in the KF0602D. With the switch closed, current flows from the power supply through the switch, to the valve and that opens. When the switch opens no current flow and the valve closes.

  When I plug my 6008 in the KF0602D, however, my 'high' digital output falls from 5V to 1.73V. It's a problem because my switch requires at least 3V to close. I don't know why the voltage decreases because the relay is supposed to just on 3mA current with an input 5V, wells in the area of the specs listed 6008. What can I do to make this work?

  Outputs digital USB-6008 are drain opened with pull-up 4.7 kohm resistors. This will NOT lead your SSR entry requiring > 2 my.

  He must reverse the polarity of your control signal. Wire-entrance of the Republic socialist Soviet to the line of the 6008.  Wire the + input of the Republic socialist Soviet to + 5 V. Then you have the 8.5 my driving ability to do what you want.

  Lynn

• How can I more easily generate a pulse of digital output of finite length?

  Hello

  I need to open and close the two pneumatic valves using a TTL output (without load current or the output power) using a PCI-6280 or PCI-6601. The valves must open almost simultaneously and closing after different amounts of time elapsed (millisecond level timing, maybe 100 microseconds-level timing at worst). My current plan is as follows:

  -Create a task with two digital outputs (type of waveform) and another task with a counter that generates a frequency set by the user (I know I can use the generator frequencies on one of these cards, but I would have preferred a counter - the best selection of frequencies).

  -Wire the output of the counter at the entrance to clock two digital outputs.

  -Output of the meter is digitally triggered by another digital channel which I use to control if the pulse goes out. Through its counter node, it is programmed to be redeclenchables.

  -Two digital waveforms are drafted who have both consist of unique active high pulse (i.e. signals go ' down (for the amount of time user-defined) - low ".")

  -These signals is written to their respective ports and their tasks have started, as is the task of the meter.

  -Whenever the user wants to open taps, digital triggering is sent up and then back to low (this can be done with synchronization software, because it is not exactly when the fire valves). Whenever the user wants the valves open for a different period, different digital waveforms are generated and written in the buffers of the digital output channels.

  My problem is that it looks like a lot of effort for me to go and I wonder if there is a much simpler solution, that I don't know everything. You can program a computer to produce a pulse of finite length? Is there a faster way to program a digital output for that channel?

  Thanks to anyone who responds to their help.

  It is certainly instructive. Thank you.

  The thing is, I have only six total counters to work with and I have a lot of time to do things. To use these solutions, I would need to use 4 or 6 account counters required to my needs.also that I would need to synchronize their departures.

  Overall, I stick to my method for now - less system resources and synchronization can be don by using the same meter of finished output clock and not to use a trigger to all.

  Once again, thank you for your help so far.

• Analog input base changes during digital output in parallel

  Hi all

  We use a USB DAQ 6008 to run a simple system. AI6 is connected to a motion sensor; digital outputs control a pump. We noticed that if we read AI6 without performiong of additional tasks, the baseline is ~0.17V and when movement is detected it comes down to 0.13V. However, if we read AI6 while performing outputs digital at the same time, the base line comes down to ~0.14V and when activated he descends to ~0.1V, i.e. the line base modified by 0.03. We do something wrong or is this expected behavior?

  Thank you

  Danielle

  Danielle,

  You may have a ground loop. If the current of the pump or even digital control for the pump through the Earth wire similarly that the signal of the motion sensor, the voltage drop in the common driver because of the current pump could cause an effect like you report.

  Lynn

• PCIe-7842R (series R FPGA) digital output does not work properly

  Greetings,

  I'm having some problem show TTL the correct voltage with my PCIe-7842R FPGA board.

  The block diagram of my code FPGA LV Moose appears in "analog - digital .png '. The idea was to convert an analog input (decimal value) to a binary code and 16-bit output by 16 DIO ports. I use the connection block SCB-68 has as the terminal and trendy on the FPGA 1 connector RDIO with SHC68-68-RDIO shielded cable.

  The compiled code ok. But during the test, I noticed that some ports has no output TTL levels correctly. For example, for input 1000 decimal, I would expect binary code 0000001111101000. However, some ports (DIO #6, #7, #9, etc.), which are supposed to ~3.3V (1 digital) high TTL output, output actually 0.8V. I have attached the result measured in 'exit digital test.png '.

  To ensure that the question was not because of the code of the LV, I did some more tests on DIO #6 with a simple example (simple digital output.png). The output was ~ 1V this time at the digital 1.

  It's really confusing because of the digital Edition is supposed to be simple. I used the same FPGA card for controlling roller shutters with TTL signals before and it worked fine.

  Does anyone have similar problems? Any suggestions are greatly appreciated.

  iron_curtain wrote:

  DIOs are connected to a controller digital galvo Cambridge Tech. But I measured the voltage at the terminals of the connector block.

  If you unplug the controller galvo DIOs, do they look good (have the right voltages).  Do you know how many of these entries to the need for controller?  I think you hit the limit the total current available for EID within the Council.

• Acquire the values only when the digital output is high.

  Hello

  I work with test of transistor, whose door is controlled by the digital release of USB6289, related to BNC2120.

  Test plan:

  Door 1.transistor is enabled for 5seconds, with P0.0 for example

  2. then, everything remains off for 1secondes.

  3.p0.1 is used as digital output to activate the circuit passing him curent through in the opposite direction, P0.1 goes high for 3 seconds, PS: Gate is off.

  4. the same cycle repeats again.

  My question is to store values to the output of the transistor when P0.0 and P0.1 goes high, and these values should not change until my digital outputs respective again go high.

  I can access transistor by continiously read out my power supply values.

  and in the State off I want to read AI0 because at that time, my power supply is off, so that I can activate the circuit to pass the current in the opposite direction.

  Again, my question is to gain the output through power value when P0.0 is high and store them until the transistor turns on.

  and even for P0.1, acquire the value of output through AI0, when P0.1 is high and store it until it goes high again.

  Hopefully, I'm able to explain my problem clearly.

  Please help me.

  Concerning

  Anurag

  Think about what States (object:statemachine and determine when to use sequence Structures) do you want from t0... t(n-1), IF DAQmx generates outputs and/or inputs are absorbed and what needs to happen (event timed out), before move you on to the next 'State '.

  type def 'enum' with your different States:

  • initialize
  • wait (the user initializes times (sec) set for States, or whatever and presses button 'Start')
  • T0 (generate DigOutputs, store acquired data AnalogOutput (string output number) the register shift, before moving to the next State > user 'set time' must elapse (Note: the wait function allows you to control the rate of execution of loop and allow the CPU to respond to external events and system tasks and avoid using wait functions at the same time an operation of software...))
  • ...
  • t(n-1) if ' end (made requirement) "> goto 'stop', ' another (not requirement not)" > goto regardless of 'State '.
  • stop
  • write a text file of data (string).