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Taking Consecutive Measurements on Agilient 34970A

June 28, 2017, 1:27 pm
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I am working on a project where I am using an Agilent 34970A to read DC Voltage from 100 channels and read one K-type thermocouple, using the three 34908A single ended Mux boards.

I am having no issues with the thermocouple measurement as the program just needs to call 1 measurement every 5 minutes.

 

The Issue that I am having is that the DC Voltage measurements are used to measure a bias voltage during power on of a sensor. Each time I take a measurement, it cuts the channel on and then off again. When the sensor loses power the bias voltage does not stabilize.

 

Essentially, I need to be able to turn the channel on and take multiple readings until I am able to read 10 readings that are "stable" (most likely will be determined by an average rate of change).

For the test I am not concerned about the speed of the readings as the majority of my test time is taken by waiting for the sensor to stabilize.

The closest I was able to get was to take multiple readings as quickly as possible so that the voltage loss of switching was minimized, but the results are not accurate enough.

 

Below is a snippet of the code I am using. I am not getting any errors running this code, and I am able to read from any channel any number of times, the only issue is that the relays on the 34908A switch off between each measurement.

Read Channel.png

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Parallel port not detected in MAX

June 28, 2017, 1:42 pm
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Hello,

I'm trying to communicate with a Tektronix TDS3054B oscilloscope through LabVIEW. The oscilloscope only has a parallel port, so I've used a parallel cable to connect the oscilloscope to the parallel port in the computer (Windows 7). The Device Manager recognizes LPT1, but in MAX the port doesn't show up under Devices and Interfaces. I have NI-VISA installed as well as the Tektronix tds3000 series driver. Is there anything else that I need to get MAX to detect the parallel port in VISA resources?

I'm fairly new to LabVIEW so any help would be appreciated. 

 

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Measure voltage continuously for 2 hrs or more

June 29, 2017, 9:21 am
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Hello

 

Im trying to do a sensor setup, where I need to measure the voltage continuously. Im supplying current 10E-9A using Keithley 220 current source and measuring voltage using Keithley 6514 electrometer. Everything works fine until time runs out and reset the measurement. Once it reset there is a spike in data which is not true. So I would like to continue collecting data for atleast 2hrs without resetting Keithly 6514 electrometer. I have attached the file I have been using.

 

Please do let me know if this can be done.

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Using NI USB-232/4

June 30, 2017, 5:06 am
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Hi All,

 

I have to develop functional test system to test 4 devices in parallel which communicates on RS232. I am thinking of using  

Using NI USB-232/4 for my application. It will be helpful if anyone can share their experience in using NI USB-232/4. Also, I am open to any suggestion for a better configuration.

-Anurag

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Experimental linux-usbtmc kernel driver

July 1, 2017, 12:56 am
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An experimental version of the linux usbtmc kernel driver has been released at https://github.com/dpenkler/linux-usbtmcfor folks to test and suggest new features before having them submitted to the upstream kernel.

 

The current version of the driver has some additional capabilities that have not yet been submitted upstream. These include module parameters to configure the buffer size and usb timeout and also an ioctl to send a device trigger. 

 

The build and resulting driver have been tested successfully on  "3.16.0-4-amd64 #1 SMP Debian 3.16.39-1+deb8u2" and a stock kernel.org 4.11.3, so should build OK on the intervening kernel versions.

 
Please see the README of the project for more details.
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USB Adapter

July 2, 2017, 5:24 am
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Hello Sir,

In Vimar USB socket connector, I have connected +5V and ground to that USB connector and left D+ and D- without any connection. But I cant charge my apple phone and apple ipad through this.

 

Please let me know what should do for it and what are the connections should I do in Vimar USB socket.

 

 

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Using RS232 and cDAQ 9178 to connect to LabVIEW - Compatibility concerns

July 3, 2017, 2:33 am
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Hello, 

 

I am currently evaluating which NI DAQ hardware to acquire to test a motor controller drive system. 

 

I wish to exercise about 30 different terminals on the motor controller using the cDAQ 9178 using the necessary modules. 

 

My major concern at the moment is the fact that the cDAQ-9178 only has one USB port available which connects to the PC. After speaking to an NI application engineer I was advised that the USB-cDAQ, doesn’t have a RS232 port, and the RS232 serial modules are only compatible with cRIO, not cDAQ, so there is not a C-Series module for cDAQ that provides RS232 communication. Therefore the RS232 port which is situated on the motor controller would have to be connected directly to my PC. This mean's that there are two USB ports occupied on the PC. So does this cause compatibility issues with LabVIEW in terms of synchronization and functionality. I feel that timing and sequence will be a crucial feature for the DAQ to endure. 

 

The RS232 will be used for non standard protocols which I want LabVIEW to communicate with as well as LabVIEW being used to manipulate terminals. I am currently trying to find some useful examples on the forum that will illustrate something similar to that, i.e. a VI that illustrates how to read/write script file language to easily manipulate the terminal configurations.  

 

Perhaps you may have suggestions as to: 

a. Is the compact DAQ chassis suitable for what I am trying to achieve? - if not what should I use?

b. What problem may I encounter with the above setup?

c. Any better solutions for what I propose to test. 

d. Some similar VI example of how to achieve the system above. 

 

Many Thanks

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RFID Reader - Labview communication

July 3, 2017, 10:15 am
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Hello guys,

 

i am currently working on the RFID chafon 6m UHF reader/writer. I have all the documentation related to the reader like the .dll files, functions and demo software for the reader. I am using a serial to USB converter to connect to my PC, i have downloaded the necessary drivers for the converter, launched the reader's software and its working fine. However, i am having trouble communicating with the reader using Labview. I tried using call functions for the .dll files but didn't quite know how to work with it. I then switched to using NI-VISA. In MAX i can see the serial port and says " device working properly" so i went ahead and built a VI that configures the parameters of the reader such as baud rate, stop bit, number of bits, etc.. and i used VISA write vi to send a command such as 0x21 which calls the reader's information then wired that to the VISA read vi with a property node that gets the number of bits between both the write and read VIs and finally converted that to a string, but it returns 0 bits and an empty string.

Is there a way to tell the reader than i want to perform a specific action and read the output?

 

Thank you,

Fadi 

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Remote control LeCroy WaveRunner 64xi with Labview about configure timebase

July 3, 2017, 9:55 pm
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Hi，

I'm using labview to control Lecroy waverunner 64xi.

Does anyone know how to change the timebase?

It doesn't work when I use the "Configure Timebase.vi". Even I use the example to change it, the oscilloscope still has no response for the timebase. 

Here is the driver I used.

 

Best regards

Haojie

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Read data from Agilent 86100C Oscilloscope from GPIB interface

July 3, 2017, 11:09 pm
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Hello everyone, 

trying to get my head around it. i am using Labview to control Agilent Oscilloscope 86100C to retrieve the signal and be able to plot the waveform in Labview. i have installed the device's drivers and used one of the existing example "Agilent 86100 Series Aquire Waveform.vi". when i run it i receiver an Error says : 

 

Error 1 occurred at Scan From String (arg 1) in Agilent 86100 Series.lvlib:Fetch Waveform (Normal).vi->Agilent 86100 Series.lvlib:Read Waveform (Single).vi->Agilent 86100 Series Acquire Waveform.vi

 

Not sure what exactly need me to do, but when i click on STOP in the Error window, it takes me where the Error has occurred Fetch Waveform (Normal).vi 

in this VI, the Error occurs in SCAN FROM STRING block as following. 

 

Error 1 occurred at Scan From String (arg 1) in Agilent 86100 Series.lvlib:Fetch Waveform (Normal).vi

 

i would be very much appreciate it, if someone could guide me on how to tackle this issue,

 

many thanks,

 

 

 

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Signal choppy from VISA, except when NI I/O trace running in background

July 3, 2017, 11:36 pm
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Dear Folks,

 

Strange issue, have been trying everything that i Know.. but unable to crack it. 

Simple Serial port data ( from 1 sensor and 1 encoder) - 

RS232- to -USB converter and reading in my program. (LV 8.5)

Works fine in my other computer with windows 10

in my customers system (windows 8), the signal is choppy esp from encoder.'I tried varying all possible parameters but to no avail

I ran NI I/O trace in the background.. an the signal is no more choppy!!

Trying to find out how I can run the app in this system without Trace in the background all the time... 

 

Any help is appreciated.. Atached are the pic of the block diagram and that of the signal, with and without trace..

 

Thanks,

Palch

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BH485-DO Unable to get data from sensor

July 4, 2017, 3:04 am
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hi i bought BH485 DO sensors from snboqu a chinese company .am unable to connect the sensors to rs 232 to 485 convertor to read the data . am getting various error msgs when using diff modbus.

like with Mtester : No POD detected . and with simple modbus master : timeout  .

can some one explain to me abt how to get the data from the sensors using rs485..

 

thank you

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How to manipulate specific cDAQ terminals simultaneously

July 4, 2017, 5:50 am
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Hello Everyone, 

 

I have been looking at the DAQmx functions in LabVIEW in terms of independently manipulating the cDAQ module terminals. 
 
It seems as though the DAQmx function blocks are stuck to certain parameters such as Min/Max voltage. However for example, say that during the LabVIEW simulation run I wish for multiple and/or single parameters to change automatically after a specific time-frame of 10 seconds, is it possible? 
 
I concluded that it would be easier to write script files to manipulate the cDAQ terminals rather than trying to use an excessive amount of function blocks. Would anyone have any better ideas of how to best tackle this without creating using a large block diagram space?
 
I feel that having a more programmable scripting format would be easier to manage whilst still taking advantage of some of the front panel features available that LabVIEW offers. 
 
Does anyone have any examples of achieving something similar to what is mentioned above? 
 
Many Thanks
 
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convert commands in PuTTy to visa resources write read in Labview

July 5, 2017, 11:47 am
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I have an instrument (a complicated RF voltage source) that I currently able to control from PuTTy, which is rather a cumbersome interface. I want to control the instrument though LabVIEW. I have never used the VISA resources commands, I always used the LABVIEW provided VIs of the instrument I am interfacing which don't exist for this. Right now in PuTTy, to change say the frequency I enter: <freq 3, 150> followed by <latch 3> to set the frequency to 150 MHz. Can someone help me construct the equivalent LabVIEW code using the write and read in VISA. Also, to access the instrument through PuTTY I have to first enter the command: <soft on> to put it in software mode, can you also help me code this as well. I appreciate all the help.

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Have to add a delay in Agilent 3446x labview driver

July 5, 2017, 11:50 am
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I was seeing a weird bug in the Agilent 3446x driver on the driver page.

 

Running initialize.vi results in a long wait (~2 minutes) followed by this error:

 

Error -1073807339 occurred at VISA Read in Agilent 3446X Series.lvlib:Error Query.vi->Agilent 3446X Series.lvlib:Reset.vi->Agilent 3446X Series.lvlib:Initialize.vi

 

Possible reason(s):

VISA: (Hex 0xBFFF0015) Timeout expired before operation completed.

 

Then if I run the code again I get this error:

 

Error -1073807360 occurred at VISA Open in Agilent 3446X Series.lvlib:Initialize.vi->Ivan acquire single.vi

Possible reason(s):

VISA: (Hex 0xBFFF0000) Unknown system error (miscellaneous error).

 

I narrowed it down to a read call in Error Query.vi. I was able to fix it by inserting a 1 second delay in between.

 

error query.PNG

 

I thought I'd write this up for anyone encountering this issue in the future.

 

I'm testing with a keysight 34465A firmware V, Windows 10, and Labview 2017.

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Communicating with NI9264(Voutput) and NI9209(Vinput) modules.

July 5, 2017, 1:25 pm
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I have cDAQ voltage output and voltage input modules.
When I try to have a voltage output (from the output module) read by the voltage input module, the input always measures ~0.9V different than the output. (A few examples)
ie: Vout=10V  Vin=9.1V
Vout=-10V  Vin=-9.1V

Vout=0  Vin=0V

 

Is there some kind of voltage drop I am missing from the hardware units?
Why don't they read the same and are always offset by ~0.9?

Thanks in advance!

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Question on selecting and installing driver for GPIB-USB-HS on Windows 7

July 6, 2017, 5:16 am
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Gentlemen,

I have a GPIB-USB-HS adapter in our department that I want to run on Windows 7 Enterprise SP1 machine with a 2011 Base Version LabVIEW installed package.  My VISA is 5.1.  I need this to communicate my Yokogawa WT500 via GPIB, and further build an application to record data to Excel, etc.

I am looking for the proper NI driver online. Can I just select the latest like version 17 that I see out there, or do I have to go back and select something that is more comparable to the 2011 install that resides on this machine?  I tried installing a later one, and I get an error saying its not a valid 32-bit application.

Any suggestions would be appreciated.

Regards,

Eric

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Controlling an Agilent E4426B over GPIB

July 6, 2017, 6:32 am
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I'm trying to change the frequency and amplitude of the E4426B Signal Generator remotely, but I can't for the life of me figure out these commands.  The device shows up in NI Max and I can open an "Interactive Control" with it, but none of the commands get me anywhere.  I tried to use "ibcmd" but I get an ECIC error because "The interface is not the Controller-In-Charge", then I fix that with a command and get an ENOL error because "No listeners are on the GPIB," which doesn't make sense to me.  The GPIB address of the sig gen is 1, and in the GPIB Settings in NI Max the Primary Address is also 1.  I realize this device is very old but I have nowhere else to go.  Any help would be appreciated.

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Keithley 2400 gpib labview connection

July 6, 2017, 1:02 pm
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" I am trying to add a keithley 2400 sourcemeter device through GPIB 120 A Bus expander /Isolator , But The device is not being detected in NI MAX , I can't figure out what to do?

I have connected cable from pc to gpib ni 120a bus A and keithley 2400 is connected with Bus B.

 

 

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Acquire and graph Counter input v/s analog vltg from sensor

July 7, 2017, 12:25 am
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Hello Folks,

For my project i need to acquire data from one encoder(counter) and one sensor (analog vltg).

I could program using VISA, but sampling rate not sufficient (nned 100sps), hence trying with 6008..

 

attached is the pic , tried with timed loop- if only counter/encoder data is being received, it works fine records fine.. combining both, gives me counter data only once in a sec..

How do i solve this..

 

Thanks,

Palvi

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