Dc voltage control using GPIB

Hi ....
Can any one help me out in designing a VI which is used to control the external dc voltage source( max voltage 60v ).
Thanks and regards,
Sampath kumar chennuri.

You left out the most important part if you want any detailed help. Namely, what is the make and model for your power supply. You can go to http://sine.ni.com/idnetwork/ and search for a driver for the instrument. You should also have a programming manual for it. With the manual, you can write your own program with VISA Writes and Reads or use the Instrument I/O Assistant.

Similar Messages

Simultaneous Control Using GPIB / DAQ

I am working on a project that is a continuation of a previous project. It involves controlling the temperature and pressure in two vacuum chambers. The original project controlled only one chamber and the original code contained a number of global variables. In order to control the temperature and pressure, the LabVIEW code reads in values from a data logger thru the GPIB interface. To regulate the temperature/pressure, a DAQ card is used to control a heater and a series of pressure valves. The client wishes to keep the original code and is asking me to incorporate code to accomodate the second chamber. One computer will be running identical LabVIEW programs(with different global variables and sub-VIs), one to control each chamber.
I am fairly new to LabVIEW and looking for a starting place or sample code that I can look at. I have duplicated the current code, renaming sub-VIs and global variables. The solution I have come up with so far is to have a VI that does all of the reading and writing, but I am unsure as to how the chamber LabVIEW programs will access it whenever a reading is needed or the temperature/pressure needs to be adjusted.
If further explanation or the original code is needed let me know, and thanks in advance for any advice that can be offered

Hi lrsantos,
It's unfortunate that you have to maintain the original architecture of the code, because this type of application would most likely be better implemented in a single top-level VI with subVIs. However, if that is not an option, I understand.
So, using notifiers you are able to easily transfer information between "independently-running" VIs. There is a very good example program on this (Wait on Multiple Notifiers.vi) that ships with LabVIEW. You can access this by going to Help->Find Examples->Search "notifiers". This actually does almost exactly what you are thinking about doing. You can make a 3rd VI that reads the information off of the USB port and then sends that information (via Notifier1 or Notifier2, depending on the chamber) to its respective VI. For example, one VI would be waiting for a notification (and data) from Notifier1 and the other VI from Notifier2. You could then process this information accordingly. Like I mentioned, this shipping example should show you exactly how to do this with the exception of 1 thing. If you are passing notifiers between top-level VIs, you will need to write the "notifier out" to a global from your 3rd VI and read it back into your 1st and 2nd VIs (to be passed to Wait on Notification functions).
As far as priority goes, you won't need to do anything. The way that I described the "3rd" VI as operating is more like a Producer of data and the "1st" and "2nd" VIs act like Consumers. Therefore, the Consumer VIs don't ever really "access" the 3rd VI, they are actually sent data from the 3rd VI.
Hope this helps!
Travis H.
LabVIEW R&D
National Instruments

Using Visa "resource name" control with GPIB example

good morning
I have in my pc two resources of GPIB (Ni-Enet and HP-HPIB card) each one has differet VISA name (ie:GPIB0,GPIB1)
means Ni-Enet is GPIB0 and HP-HPIB card is GPIB1.
I tries to use the example Labview<>GPIB to communicate with GPIB1 but it failes
because the address given (string), to the gpib write object is a string and it recognized only the GPIB0 addresses
i tried to use the "visa resource name" control (used in the example Labview<>Serial)
in the Labview<>GPIB example but it failed. ("visa resource name" shows all resources includes GPIB0 nad GPIB1)
tell me pleae how to use the Labview<>GPIB example to communicate with the equipment addresses used in GPIB1
a bit long , but hope the issue is clear enough..
thanks in advance
Happy new year.
Simon

You can't use that example with an Agilent GPIB board. The GPIB functions are only for NI boards and the NI-GPIB driver. You should be able to convert it to VISA but you'll have to replace the GPIB Writwe/Read with VISA Write/Read as well as changing the GPIB Address String to a VISA Resource Name.

I'm working on DC Motor control using DAQ. There is sufficient voltage output from DAQ but not current. What should i do so as to drive the motor

I'm working on DC Motor control using DAQ. There is sufficient voltage output from DAQ but not current. What should i do so as to drive the motor. Could you suggest me appropriate driver IC using which this problem can be solved.
Saravanan.T

You really should use a DC motor controller to control a DC motor, look at the 754410 IC for a good example. You should be able to interface these to most DAQ devices.
Alan

How to read from a HPIB instrument using GPIB software?

How Can I read from a HPIB instrument using GPIB software and library functions in Visual Basic Environment? In HPIB we do not have to send query first but in GPIB we do? Although writing and sending a command is to a HPIB instrument is pretty much the same as a GPIB instrument. Any help or suggestion?
Thanks in Advance
Shazaduh

HI,
HPIB and GPIB are the same thing at a low level in terms of instrument communication. They are both compliant with the IEEE 488.2 standard.
The difference is the driver you have to use. Each manuafacturer has to develop a driver to control the interface ont he host. For National Instruments interfaces you use NI-488.2 (which you refer to GPIB functions). For HP interfaces you need to use the SICL library. For information using this library in Visual Basic you'll have to look at the SICL documentation.
You can also use VISA (HP-VISA) which would allow you use NI interfaces or other buses in the future.
Hope this helps.
DiegoF
National Instruments.

Is it possible to do torque control using Flex Motion?

I am trying to control the output torque to a motor?
I know you can do velocity control using FlexMotion, how about torque control?

To hold a servo motor at constant torque, all you need to do is provide a constant voltage. You can accomplish this using the analog output (DAC) of a FlexMotion board. To gain access to the DAC, configure the axis as an open loop stepper, then use the Load DAC.flx VI to output an analog voltage. The downside to this is that you won't have feedback, so you'll have no way to determine your position.

Throttle body PID control using pulse width modulation

Hello all,
I am trying to do a PID control for a throttle body (using pulse width modulation) for a set value of feedback voltage. The process variable is the pulse width duty cycle. The throttle body is expected to be fully open at a feedback voltage of 5V and pulse width duty cycle of 42.5%. When I use the highlight execution using the attached file, I can see the throttle body fully open (the values observed are: PID output 42.5 %, feedback voltage approximately 4.7V). However, when the highlight execution is unclicked, the throttle body flutters in the closed condition (still PID output 42.5%, feedback voltage approximately 0.9 V). Can any one please help by suggesting any modification to this attached file to make this throttle body respond to the set value of feedback voltage.
Many thanks
Ajith
Attachments:
Throttle body control using PWM technique - PID.vi ‏525 KB

How did you determine your P, I, and D gains? If you have not tuned your controller, you'll get poor performance. Running with execution highlighting will slow down the execution, which will change the effect of the gains. I would start with pure proportional control (I and D = 0) with a small proportional gain, and see if it responds in approximately the way you want. If so, then your code is probably correct, and you just need to do a full tuning to get good performance. There are many resources available on the web, on this forum and elsewhere, for PID tuning. Note that since your code uses a simple PID example, and not the one from the PID toolkit, the gains do not have the units that are used in many tutorials so you'll have to correct the calculations to compensate.

Reboot Window 7 and Voltage Control in Afterburner is gone (N460GTX)

after i got my MSI N460GTX HAWK card and i use MSI Afterburner 2.0.0 with Driver 260.99 i haven't tried older or newer driver but when i reboot my Windows 7 Ultimate x86 my voltage control is gone and i have to unclick them, restart Afterburner, click them restart Afterburner and i can adjust them again, i was wondering if it's Afterburner or card (Software or Hardware) problem?

Quote from: Henry on 27-November-10, 06:47:20
Do you have it set to apply at system startup? Do you have a saved profile for it to startup on? Do both and it will apply your settings each time you cold start or warm re-start your PC.
Edit: Where I have it underlined in red, click on the little green button on the left to apply at startup.
This is not related to voltage unlock setting
Quote
click them restart Afterburner and i can adjust them again, i was wondering if it's Afterburner or card (Software or Hardware) problem?
Software issue for sure.

Using gpib-32.dll in Labview 7.0

Hi there,
I am relatively new to Labview and I need some help trying to program an old HP3488A switch/control unit using the Call Library Function Node. I would like to convert the existing VB6 code, which uses gpib-32.dll, into Labview. What I have done in the VB code is to call the ibdev function to set up the HP instrument. I would like to do the same in Labview. How would I even go about setting up the .dll files as I am revamping the existing code (running on a Pentium II computer) and trying to create an identical code in Labview (running on a Pentium III computer). Also, after I have set up the .dll files (done any system configurations if necessary), how do I actually implement this file in Labview?
I have tried calling the ibdev function in the properties of the Call Library Function. I created 6 parameters of return types with ranges of type long. Then I pass integers into the input of this node and when I tried running it I get an error exception within the external code as follows:
"An exception occured within the external code called by a Call Library Node. This might have corrupted Labview's memory. Save any work to a new location and restart Labview. VI "switch.vi" was stopped at Call Library Function Node 0x1D7C of subVI "switch.vi"
Can someone please help me? Thanks.

I actually tried that before. As the HP3488A switch instrument is very old and came out before IEEE488.2 got introduced, it still uses IEEE 488.1, or HPIB commands. When I try using MAX or even my Agilent IO Control, it shows that there is an instrument connect to GPIB address 10, but neither programs can auto-identify the instrument using the *IDN? query. Even so, I tried typing ID? in both programs and I got no data back from the instrument. I'm not too sure as to what the problem is since I always get "\n" back from the instrument's reply. I even tried changing the termination character enable to TRUE and I still got nothing back.
However, on the front local display of the switch, I can see arrow indicators moving between TALK and LISTEN whenever I perform a write or write/read command. But no data gets sent or received because I couldn't perform any write commands to change the switch. If anyone can tell me what the real problem is that would be great. But if not, then I will have to use the Call Library Node because I know that my VB6 code actually works on the HPIB instrument and I could simply use this gpib-32.dll file on Labview and perform the same instructions, which should allow me to talk to the switch. Can anyone tell me how to properly set up a Call Library Function Node as I have errors using the gpib-32.dll file (please see my previous message)?

Unlocked Voltage Controll

Hello.
I've got MSI GTX 670 PE and I'm using MSI Afterburner ( 3.0.0 Beta 9 atm. but with 2.2.3 and other versions I've got the same problem ).
The voltage controll is unlocked, I'm able to controll mem voltage, I got +745Mhz ( 3746Mhz total ) mem to work on +50mV.
Actualy this is the only unlocked voltage that works. Changing Core and Aux Voltage has no effetc ( either -100mV and +100mV, the readings are same all the time ).
Actualy I got +70Mhz ( 1320Mhz total ) set on it with +0mV but as I said voltage dosen't work.
I'm wondering how to fix it, maybe its coused by my BIOS ? I'm using 80.04.4b.00.47 which is default for my card.
Also, I'm using driver 314.22.

The vbios of most GTX670 PE are limited to 1.175v max due to Nvidia dictating that when production started. Aux voltage increase works but you can't monitor that with software.
Check this thread: gtx 670 power edition OC unlocked bios?

MSI 7950 twin fozr has no voltage control

Is this card supposed to have voltage control for the memory?
I can change the core voltage fine. Gpuz and afterburner graphs shows the correct core voltage. But when I change the memory voltage sliders and hit apply, gpuz and the afterburner graphs don't change from default 1.6
I think this card is supposed to have memory voltage control because the vrm model number allows it and afterburner is showing me the memory voltage sliders.
But I can't get it to work. Any help?

Interesting.
The reference 7950 and 7970 boards using the chl 8228 voltage controller do have memory voltage control.
The 7950 card I bought uses the 7970 ref board design with chl 8228 controller.
So the card does or should have the capability based on the hardware. But if you disabled it on the software side to differentiate your product line, that is fair and I can live with that.
But if you are saying the hardware does not support it, then I think something is not right.

MSI Afterburner - MSI 7850 Voltage Control

When will afterburner support voltage control for this card? We're able to unlock voltage control in options but still not able to change the voltage control in afterburner. Other mis 7970 cards can use it fine, not this msi 7850 though.

Hi again
I have been doing some further testing today, using the AMD Catalyst drivers v12.8 and MSI Afterburner v2.2.3.
THE MSI R7850 Power Edition 2GD5 card appears to have two GPU core VDDC voltage states as standard, 0.82v for 2D clocks and 1.21v for 3D clocks.
I have confirmed this using GPU-Z v0.6.4 (managed to get it to display current VDDC correctly at last) and AIDA64. For some reason , Afterburner lets it appear that you are changing the VDDC voltage (once the unlock voltage options are ticked in settings). Afterburner shows a core default VDDC of 1075mv when first installed which doesn't tally with what is actually the current 3D clock VDDC voltage of 1.21v. Even sliding this to 1.1v or 1.3v (the maximum) has no effect on the VDDC or 1.21v. The Afterburner OSD will always display what the voltage is set to on its own slider, even if sensor output still shows the actual 1.21v.
Now, this is where it gets interesting. I installed the Sapphire Trixx application which as you probably know, is similar to Afterburner. Right at the start, it was displaying the adjustable core VDDC voltage as 1.21v although the slider would only let me decrease the voltage. I believe that this is due to Trixx having a VDDC limit of 1.18v. To test Trixx, I reduced the core VDDC to 1.1v. This core voltage adjustment was successfully reflected in MSI Kombustor, AIDA 64, GPU-Z when running 3D..
Strangely, this means that the Trixx application will let me adjust the volatge on MSI Power Edition GPU core, albeit only to down volt from 1.21v where as the MSI Afterburner app does not adjust the core voltage at all, despite the fact that on the surface, it appears to work, letting you select core voltage 0.82v all the way to 1.3v. The 7850 states that it is triple overvoltage enchanced but Afterburner will not bypass the hard coded MSI BIOS voltages.

Recording Temperature and Voltage measurements using Keithley 2182 Nanovoltmeter

Hello all,
I am relatively new to LabView and looking to extend a vi I am currently using.
I am trying to record voltage and temperature measurements from a Keithley 2182 nano voltmeter using a GPIB cable. I have a vi that can do this for either voltage or temperature not both. At the moment I only record what is shown on the display of the nano voltmeter.
Could somebody explain how I could get labview either to change between voltage and temperature on the nano voltmeter or whether it is possible to have two simultaneous measurements of temperature and voltage and how I would achieve this.
Thanks
Mike

Hi,
For each read, no matter Temperature or Voltage there is a certain command that is send to the voltmeter.
I don't think (actually I'm pretty sure) you cannot read it in parallel but you can do it successively: One read Voltage, one read Temperature and so on.
There should be something like:
while not STOP do
1. send GPIB command for changing Keithley to Voltage Measurement
2. send GPIB command for Voltage Read
3. read GPIB -> Voltage
4. send GPIB command for changing Keithley to Temperature Measurement
5. send GPIB command for Temperature Read
6. read GPIB -> Temperature
end
You can take a look in VI to see which are the commands send for Voltage and Temperature reads and to mixed them like I described it above.
If you don't manage it share your VIs (for temp and volt.) maybe it will be easier for me (or something else) to give you some additional advices.
Paul

What is voltage control mode in MSI Afterburner?

Hi, I have a reference GTX 970 and am wondering what the difference voltage control modes are in my afterburner settings.I have the option between reference design, standard msi. and extended msi.
Which should I use, and what's the difference between them?
Cheers,
Ben

Standard msi is for normal msi graphic card and Extended msi is for like msi Lightning kind of cards. Extended mode sometimes opens up some settings just for those cards. But basically they are the same.

Power across voltage controlled capacitor

Hi, I have the a basic enough circuit (attached). I am modellling a mechanically variable capacitor using the voltage controlled capacitor element.
I wish to measure the power across this capacitor as I am trying to calculate the electrical efficiency of the circuit, but it seems that this voltage controlled capacitor element is not really acting as an actual capacitor.
Can anyone help me on this?
Thanks
Rachel
Attachments:
interface.ms11 ‏55 KB

Hi Rachel,
I looked at the circuit. The voltage controlled capacitor is not connected to a voltage source to act as a capacitor (unless you're controling it using LabVIEW which is another possibility). You need to connect a voltage source to the two bias terminals of the voltage controlled capacitor and according to the conversion ratio (how many Farads per volts) the other two terminals will act as a capacitor.
Please check the attached circuit and let me know if you need more help.
Mahmoud W
National Instruments
Attachments:
interface.ms11 ‏65 KB

Dc voltage control using GPIB

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