Valve control

Hello wise NI people. I am trying to use the text file attached below to control a series of valves. After several tries, I keep getting errors (200524,etc) and when it does run the sequence is way off. I have an idea were I am messing things up but I need some ideas on how to fix it. I will appreciate any suggestions or references.
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Attachments:
Flush and Sample.vi ‏58 KB
AF 17.txt ‏1 KB

Charles,
The way your text is formatted was causing an error. I took out the errors from your text and now reads in ok.
I can see that you are taking the first column to give you your time delay. You are then getting the rest of the array from the 5th column? is this what you are meaning to do? This means that in each iteration you are trying to send a 1D array consisting of 11 booleans. I have never used this hardware, could it be that it needs to see a 1D array of 16 bits and this is the error you are getting?
Rgs,
Lucither.
"Everything should be made as simple as possible but no simpler"
Attachments:
New.txt ‏1 KB

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Solenoid valves control

Hey everyone
I've designed pressure system(dp cell) with a manifold of 8 ports at each of which solenoid valve. What I'm trying to do is to control the valve through labview so the open 1 at the time, stay open for 30 seconds then close and another one is opened and so on. I've attached the data sheet of the valves. I'm using Cdaq 9178 with NI:9203 and Ni :9472.
The valves are normally closed and the fluid passing through them is silicon oil.
I've been trying to look at different examples but I got confused.
I should be grateful for any advice or suggestion you give. (I started using labview only few weeks ago).
Best Regards
Rajab
Solved!
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Attachments:
PU220AD (1) (2).pdf ‏578 KB

Hi ToeCutter
I've attached an example that I think suits my application, However when I try to edit the type Def to change the number of valve the code went blank.
I using Ni9472 (dig. output to energies the valves through Solid state relay. The valves should open sequentially at equal time interval let say(4 valves, each one should stay open 25 sec.).
The code is some thing like that:
1. Open V1 (25sec)(through Ni 9472) and start pressure measurement ( through analog input using Ni 9203)
2. Close V1 and open V2. the pressure is continuously measured
and so on for the rest of the valves
could you please suggest the best way to do that.?
Is it better to write one vi to control the valves and separate one to write the measurements. AS for my overall data acquisition system. I'm planning to measure pressure temperature, flow rate of my flow rig with one VI ( using Ni 9203)
to give you the full picture of my date acquisition system:
All the instrumentation should be triggered (using trigger out from one of the devices) to give simultaneous measurements,( the valves are part of my pressure measurements only). So once the first device is on the rest of the devices will be triggered as well as the valves control vi.
Best Regards
Rajab
Attachments:
example3.vi ‏67 KB

Valve control - user controlled, then self controlled

Hello, I am still trying to figure out a method of controlling a discharge valve for compressor testing. The valve is controlled by a slider, but when it hits a certain point of being closed, the compressor surges. At that surge point, I want the user to click a button, and then have the valve slowly open while the data is being sent to a file. This way, the data is recorded and the valve opens to prevent damage to the compressor all at the click of one button. I have the VI up and running, all except for the opening part of the valve. I have included a simple example of where I am going with the valve control. Any advice would be appreciated, for then I can implement that code for the valve opening into the rest of my programming.
Thank you,
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Attachments:
Valve control.vi ‏12 KB

JMC,
Here is an example which does what I think you want. I added a "valve setting" indicator which becomes the value you send to the valve driver. I disable the Slide when the Surge button is pressed. The event structure needs a separate case for each type of event you want to capture and should be enclosed in a loop.
Lynn
Attachments:
Valve control.2.vi ‏23 KB

Solenoid Valve control with DAQ

Hello everyone,
I would like to control 6 solenoid valves (6-24 VDC, 6W) and a small solenoid pump (12VDC) from a NI USB-6212 DAQ. I have been thinking about using a ULN2803 integrated circuit to increase the DO signal coming from the DAQ to 12VDC and use that to power the solenoids. Would this work?
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The 2803 will work, but you will need more than one since the max current through the die is 2.5A total. At 12V, your solenoids will draw 500mA each, that times 6 solenoids is 3A total. Also note that 500mA is the upper limit of the ouput drive, you may want to parallel two drivers together for each pump (just to be safe).
I could not find the current rating of the pump so once you know that figure, plan on spreading your loads between the 2803's accordingly.
-AK2DM
~~~~~~~~~~~~~~~~~~~~~~~~~~
"It’s the questions that drive us.”
~~~~~~~~~~~~~~~~~~~~~~~~~~

Best configuration for Solenoid Valve control

Hello everyone,
I'm really new with everything that concerns Controllers or Relays so any help would be very appreciated.
I want to control 5 solenoid valves (website) with the following specifications:
Rated Voltage: 12 or 24 VDC, Allowable Voltage fluctuation:10%, Power consumption (when 24V rated voltage): 1.5W (0.06A)
I want to use LabView to control them. I saw at a similar post that I would need a digital I/O device a Relay Driver and a 24V generator.
I was thinking of using these:
NI 6501
relay driver (uln2003)
and a 24V power generator.
Is this enough to control the valves with LabView or do I need something else?
Thank you for your help!
Ilan
Solved!
Go to Solution.

Yes, that combination should be adequate. The ULN2003 is designed for exactly that type of application and works well.
Usually in English we refer to power supplies when talking about devices to convert ac power line voltages to lower voltage DC.
In addition to LabVIEW you will need a DAQ driver for the USB-6501. On Windows it will be DAQmx. On Mac or Linux the dirver is DAQmx Base. The driver is a separate installation from LV, although it may come on the same disks.
Lynn

3way solenoid valve control

Problem Description :
Hi
I want to control 3way solenoid valve position using Labview. Soleniod
valve is now connected to computer through PCI-6514. What I want to do
is
as follows
1) Set time to be in position1 from front panel (range 1-5 sec)
2) Set time to be in position2 from front panel (range 1-5 sec)
3) Keep changing the position 1&2 until hit stop button
To achieve this, how can I build block diagram ? Use DAQ assistant ? Or if you can tell me which part of the Labview manual to take a look at for a start, that would be appreciated.
Thank you!

See attached. Since I don't have a PCI-6514, you will have to do that part on your own. Look for examples in the examples folder or the NI website. This is very basic stuff. If possible, take a Labview class or you will be asking these simple questions forever.
- tbob
Inventor of the WORM Global
Attachments:
TimedControl.vi ‏75 KB

First order control system for proportional valves

I am working on a proportional valve control program. We have four gas lines and it is desired to send four different gases through a combustion chamber sequentially. The close time for each valve is determined by the pressure measurement inside the combustion chamber. For instance, firstly, we let the nitrogen gas flows to the chamber, and the pressure inside the of it reaches 5 bars, we closed the nitrogen valve, and open the argon gas valve, and hold it opened until the pressure is reached at 15 bars inside the chamber and so on.
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C:\Program Files (x86)\National Instruments\LabVIEW 2014\examples\control\PID\Simulation - Lead-Lag.vi
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Barp - Control and Simulation Group - LabVIEW R&D - National Instruments

Custom controls or Xcontrols?

I would like to create custom controls that a user can drag-and-drop from the controls palette. The user will import an image showing pipelines and then drag-and-drop valves on the pipelines. I want to create these valve controls so that you can easily set their timing or connect them to other valves to have an identical, inverse or delayed response.
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Suretha wrote:
The user wil not necessarily be a developer, no.
My idea is to create a basic valve with different attributes, for instance it's timing can be linked to another valve, but then you can specify if it should be identical, inverse or a delayed version of the other valve's timing sequence.
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How to call dlls for valve system

I need to call the dll file I made from visual C++.The main theme is to control valve system from labview. I put the control switches(booleans) in labview and now want to connect it to the initial C++ program I made for valve control.Is there any way that I can use the on/off switchs(booleans) and code interface node for the system to work?Please help.I am having problems with dll calling .

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How can I create a manual control switch?

Using LabVIEW 6i, I am creating an interface to control a set of valves. Sometimes the valve control is automated, but manual control is also allowed by flipping a "manual control" switch. When the controls are in "automate" mode, they can not be switched by the user. The way I have done this is to create two sets of controls on top of one another: one is a "control", and the other is an "indicator". When I switch between manual and automatic, I change the visibility of the controls to show either the 'control' or the 'indicator', respectively. It seems that there should be a better way to do this. Any ideas?

Use your "manual control" switch to enable or disable the set of valve switches. This you do e.g. by creating a Property Node for each of your valve controls and select the property "Disabled". You can wire the states "Enabled", "Disabled" and "Disabled and Grayed Out" to all of the property nodes. (You cannot operate on disabled controls - which is exactly what you need.)
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Changing a Boolean Value

I have a number of virtual valves placed on my front panel to control solenoid valves. When these virtual control valves are pressed, they illuminate to a green color and LV writes a 1 to my fieldpoint modules, actuating the valve. When the valve is turned off, the color is red and LV sends a 0 signal to the valve. I want to know if I can switch the signal states of the valve, so that a 1 is written during a red color state, and a 0 is written during an illuminated or a green colored state.

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1. You can put a NOT vi function in the diagram, on the wire from the valve control to the rest of your VI.
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Triggering and simultaneous measurements

Hi everybody
I've written a Vi to to acquire data simultaneously from 7 devices. I'll be using cDAQ9178 with NI9203. The vi will acquire current values 4 to 20mA. Could you please check the attached file and let me know if I need to improve it.
I have some question and I should be grateful if anyone can help me to answer them.
1. How to open the binary file from write to measurement file by EXCEL?
2. Is it better to use write to spreadsheet for data logging, if yes how to include the time column??
3. I'm going to use external signal for triggering through PIF0 port, is it Ok to do that through dag assistance?? I've not tried yet but it seems straightforward?
4. Finally I have another vi for valve control that should be triggered with the measurement vi, is their any way to do that?? I was thinking about notifiers but I don't know how to use them ?
Sorry for asking to much I really in urgent need of all of this. I should finish my data acquisition system by Tuesday
Best Regards
Solved!
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Attachments:
triggering and simultaneous measurements.vi ‏97 KB

1. How to open the binary file from write to measurement file by EXCEL?
If you select TDMS as the file format in the write to measurement file, you should be able to open it directly from Excel if you install the TDMS Excel Add-In. Be aware that at 1kHz data rate, you will exceed the capability of old versions of Excel to read the entire file in about 65 seconds. Newer versions can read more, but anything over a couple thousand points gets difficult to analyze. That is about my limit. Over this, I go to something else for analysis, such as LabVIEW or Mathematica.
2. Is it better to use write to spreadsheet for data logging, if yes how to include the time column??
The write to spreadsheet file is very inefficient for data logging and cannot be recommended. Given your data (an array of waveforms), TDMS is your best bet. The write to measurement file Express VI is the easy way to do this. I, personally, prefer the control I get from using the TDMS API directly. Note that under the hood, the output of the DAQ Assistant is an array of waveforms with individual t0s and dts. The t0s are all different due to the fact that your 9203 is a scanned device, not a simultaneously sampled device. It scans at 200kHz, so the differences are not large, but they are there. I would convert the DDT into an array of waveforms, then use the native TDMS API, but I have a lot of experience. Since you are in a hurry, the Express VI using TDMS is probably your best bet.
3. I'm going to use external signal for triggering through PIF0 port, is it Ok to do that through dag assistance?? I've not tried yet but it seems straightforward?
That should work fine. Given your continuous acquisition, the trigger will only start the acquisition, not gate it or trigger it at later times.
4. Finally I have another vi for valve control that should be triggered with the measurement vi, is their any way to do that?
We do not have enough information to answer this question. Specifically, how is the valve being triggered (boards being used, hardware interface, software interface). The ideal way would be to run it through the same cDAQ 9178 so that it can be synchronized through hardware. Software synchronization cannot be guaranteed better than about ±50ms. Read up on how to synchronize things through DAQmx and you should be good.
Good luck!
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Valve control

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