Read the voltage of CJT thermistor in SCXI 1112 module, revA

The KB does'nt answear the question. I've tried every combination of physical channel names but this hasn't worked such as ob0~sc1!md2!cjtemp0 (cjtemp-1), SC1Mod2SC1Mod1/_cjTemp0 etc. Below is the vi that I'm using. Shouldn't the channel appear when browsing the list of physical channels?
Attachments:
testit.vi ‏74 KB

Steve1,
Yes, the channels should appear in the drop-down list. Make sure you have your SCXI chassis configured properly under NI-DAQmx Devices, not Traditional DAQ Devices. As a side note, what errors are you receiving when you try to run your program? This may help in troubleshooting. Have a great day!

Similar Messages

How can I read the voltage from a serial port

I am fairly new to LabView and I am having trouble figuring out how to read the DC voltage coming out of an RF Power Supply through a serial port so that I can monitor the voltage every few seconds. In order to do this do I need to purchase a DAQ card or anything like that?

You would not need a DAQ card to read data over the serial port. You would, however, need a serial port. That may sound sarcastic, but it's not, since many manufacturers are ditching serial ports on computers. If you don't have a serial port then you would need to get something like a USB<->serial adapter or a serial port card that you plug into an expansion slot in your computer.
Assuming you've got that then you need to find the command set for the RF Power Supply, and write drivers for it so you can send the command to read the voltage, and then read the resposen. I would suggest looking in the Instrument Driver Network to see if a driver for your supply has already been written.

How Can I configure the 6024E board for reading the voltage from a source?

Hi, I have a little problem, I want to use the 6024E board for reading voltage from a source and then display this on the monitor, and also I want to change the voltage from the output using the computer. I read the manual but I don't understand how to connect and configure the board. It is to proof that the board receive and send information.
Thanks, sorry for my english, I'm from Mexico, if you don't understand something about my explanation tell me.

Thank you, now I'm trying to do my project and I have another question, there are differents ways to connect the source and I choose the NRSE configuration because I'm going to use a grounded signal source... well in the manual says "The signal is then connected to the positive input of the PGIA, and the signal local ground reference is conenected to the negative input ot the PGIA. The ground point of the signal should, therefore, be connected to the AISENSE pin." I don't understand this because I only have two wires and here is talking about three connections, please help me, how do I connect the source to the board? I have the positive wire and the negative wire.... maybe is because I don't have a perfect english and I don't understand the sentence...

How to read the name of a PDF file? - function module

Hi,
I have <b>some individual pdf documents in my desktop</b>.I need to <b>bulk-upload it to the content server and document related information to the SAP-DB</b>.
Need your guidance.
Regards,
John.

try this code it will convert file to PDF file
REPORT ZWARUN_CONVERSION_PDF                        .
***********Tables***************
TABLES:VBRK.
***********Data Declaration***************
DATA: LV_NUMBYTES TYPE I,
      LV_SPOOLNO TYPE TSP01-RQIDENT.
DATA:C_LAYOUT LIKE PRI_PARAMS-PAART VALUE 'X_65_132', "Layout
      C_X       TYPE C VALUE 'X'.
DATA: NUMBYTES TYPE I,
       CANCEL.
***************Internal table of Pdf************
DATA: IT_PDF LIKE TLINE OCCURS 10 WITH HEADER LINE.
DATA:BEGIN OF IT_VBRK OCCURS 2,
     FKART LIKE VBRK-FKART,
     FKTYP LIKE VBRK-FKTYP,
     VBTYP LIKE VBRK-VBTYP,
     END OF IT_VBRK.
SELECTION-SCREEN BEGIN OF BLOCK BLK WITH FRAME.
SELECT-OPTIONS: S_BUKRS FOR VBRK-BUKRS,
                S_GJAHR FOR VBRK-GJAHR.
SELECTION-SCREEN END OF BLOCK BLK .
PARAMETERS:
spoolno like tsp01-rqident,
DOWNLOAD AS CHECKBOX DEFAULT 'X',
P_FILE LIKE RLGRAP-FILENAME DEFAULT 'C:\warun1.pdf'.
START-OF-SELECTION.
SELECT FKART
          FKTYP
          VBTYP
       INTO TABLE IT_VBRK
       FROM VBRK
       WHERE BUKRS IN S_BUKRS
          AND GJAHR IN S_GJAHR.
END-OF-SELECTION.
DATA: LK_PARAMS TYPE PRI_PARAMS,
        LV_VALID.
if not p_mailid is initial.
All the parameters passed are constants, so exceptions
doesn't get raised
    CALL FUNCTION 'GET_PRINT_PARAMETERS'
      EXPORTING
        IMMEDIATELY    = ' '
        LAYOUT         = C_LAYOUT                           "'X_65_132'
        NO_DIALOG      = C_X
      IMPORTING
        OUT_PARAMETERS = LK_PARAMS
        VALID          = LV_VALID.
    IF LV_VALID <> SPACE .
      NEW-PAGE PRINT ON PARAMETERS LK_PARAMS NO DIALOG.
*--To display the final report
      PERFORM PRINT_REPORT.
      NEW-PAGE PRINT OFF.
*---To convert the download to PDF
      PERFORM CONV_TO_PDF_DOWNLOAD.
      PERFORM DOWNLOAD.
    ENDIF.
endif.
*--To display the final report
PERFORM PRINT_REPORT.
*&      Form print_report
FORM PRINT_REPORT .
*write:/ 'I will do it' color 4.
write:/ 'Yes' color 4.
write:/ 'we will do it' color 4.
write:/ 'lets talk abt changing life style' color 4.
write:/'By warun'.
LOOP AT IT_VBRK.
WRITE:/ IT_VBRK-FKART,IT_VBRK-FKTYP,IT_VBRK-VBTYP.
ENDLOOP.
ENDFORM.                    " print_report
*&      Form conv_to_pdf_download
FORM CONV_TO_PDF_DOWNLOAD .
CLEAR IT_VBRK.
WAIT UP TO 2 SECONDS.
LV_SPOOLNO = SY-SPONO.
CALL FUNCTION 'CONVERT_ABAPSPOOLJOB_2_PDF'
   EXPORTING
     SRC_SPOOLID                    = LV_SPOOLNO
    NO_DIALOG                      = ''
   DST_DEVICE                     =
   PDF_DESTINATION                =
IMPORTING
    PDF_BYTECOUNT                  = LV_NUMBYTES
   PDF_SPOOLID                    = pdfspoolid
   LIST_PAGECOUNT                 =
   BTC_JOBNAME                    = jobname
   BTC_JOBCOUNT                   = jobcount
TABLES
    PDF                            = IT_PDF.
ENDFORM.                    " conv_to_pdf_download
*&      Form download
FORM DOWNLOAD .
download PDF file ***********
CHECK DOWNLOAD = 'X'.
CALL FUNCTION 'DOWNLOAD'
     EXPORTING
          BIN_FILESIZE = LV_NUMBYTES
          FILENAME     = P_FILE
          FILETYPE     = 'BIN'
     IMPORTING
          ACT_FILENAME = P_FILE
          FILESIZE     = LV_NUMBYTES
          CANCEL       = CANCEL
     TABLES
          DATA_TAB     = IT_PDF.
IF CANCEL = SPACE.
WRITE: / LV_NUMBYTES, P_FILE.
ENDIF.
ENDFORM.                    " download

SCXI 1112 and 1302 doesn't run at the same time

Hi,
I have SCXI 1112 thermocouple input module, SCXI 1180 feedthrough panel , and a SCXI 1302 terminal block connected SCXI 1000 chassis with SCXI 1349 adapter. I am trying to measure voltage by using SCXI 1180&1302, and temperature by 1112 module at the same time. When chassis is on SCXI 1112 runs without a problem; however, voltage reading coming through SCXI 1349 makes no sense (plus I can't run them at the same time, LAbview gives an error). While the chassis' power is off, it is the other way around, SCXI 1349 runs smoothly.
In addition to that, a radiometer, connected to a power supply, is wired to SCXI 1302 terminal block. When power supply is on, SCXI 1112 module's temperature reading is 4 times higher than actual value. In other words, power supply effects the readings.
Could you please give me some advice to solve this problem?
Thanks,
Azra

One piece of the puzzle you left out is the DAQ card being used in the host computer.
Without looking at some specifics on the SCXI cards/connectors you are using, I will comment you must be careful when you are using an 1180 feedthrough module. Keep in mind, the SCXI chassis is Signal Conditioning -- it's nothing without the DAQ.
I would recommend you back up a few steps, simplify the setup and test each input channel from MAX -- making sure you aren't overlapping channels between the 1180 to the DAQ and the SCXI chassis. Remember, most data from the SCXI chassis comes in on a single channel of the DAQ through the 1349.
Hope this might help.
RS

How can I monitor the voltage output sent to each servo axis programmatically?

Hi I am wondering if it is possible to monitor the voltage that's being sent to a servo motor during an axis position movement (in particular quantities such as max voltage). I am using a PID controller to drive this servo motor.
Thanks
Vlad

Hi Vlad,
Unfortunately, I don't think there is a way to programmatically read the voltage output to the drive, as the voltage is all determined internally by the controller circuitry on the board. Depending on the controller though, you may be able to physically route the output terminal to a spare analog input channel and read in the voltage that way. This example Analog Input with 73xx Motion Card shows you how to program LabVIEW to do this.

How to write data to the DAQ for a specified length of time while still reading the input data?

Hello,
I'm using labview 2012 and am trying to turn on a signal for a specified length of time in labview at the press of a button. The signal goes into an AO (PXI 6723) through my system, where the voltage gets divided by 2, the read in through the AI (PXI 6225). I want to write and read voltage constantly and then have a spike of voltage after pressing a button in LabView while still reading the voltage value for the specified amount of time.
Parameters:
constant voltage of 1 volt to Analog output (reading and writing) seen through a waveform chart.
for 1 second, turn on 3 volts and see the response on the waveform chart.
My specified delay time does not match the elapsed time. I am having difficulties doing this. I have attached the VI.
( I can't upload a functional VI since it shows "the contents of the attachment doesn't match its file type") How can I attach the VI?.
Thanks!
Eduardo

Mike,
Thank you for your reply! I greatly appreciate it. I currently don't have any DAQmx timing in my application. I tried using it and, without really understanding how it works nor how to manipulate it, the whole test end up taking a long time to change the values i.e. too slow.
The DAQmx timing I used was the sample clock since it was for analog signals, but I don't really understand the buffer, what that means nor how to use it. inputting a rate time for it also made my test slower. The rate time is the samples per channel per second, but I'm not sure how to determine a number so that I am collecting the data I need and take into account aliasing.
I know the PXI 6225 has the capability to read 250kS/s (which I am assuming it's kilosamples per second or 250,000 samples per second). I am using 32 differential channels. I have read that I have to divide the maximum sample rate by the number of channels, (250kS/s / channels) but I don't know if I should count the number of total channels (64) or differential channels(32). In other words, is the per-channel maximum rate:
250,000/32 = 7,812.5 samples per channel per second, or
250,000/64 =3,906.25 samples per channel per second
Furthermore, If I know the number of samples per channel per second, how can I implement that knowledge to the DAQmx sample clock so that my sampling is as fast and as accurate as it can be?
I attached an image of my DAQmx functions in my code, I merged all the stacked sequence structures in paint so you can see them.
thanks for your help!
Eduardo
Attachments:
DAQmx tasks.jpg ‏211 KB

DAQ Assist Reading Wrong Voltage

Hello,
I'm using the DAQ Assistant VI to read an analog input voltage from a National Instruments PCI-6221 card. I'm reading the voltage from pin AI0. I supply a voltage directly to this pin from a DC power supply, but the voltage measurement obtained from the DAQ Assistant is incorrect - it seems to be scaled by a factor of about 1/3. For example, if I supply 4 Volts to pin AI0, the DAQ Assist reads 1.43 Volts. I used a multimeter to confirm that the voltage at pin AI0 is in fact 4 Volts, and so I know the problem is with my LabVIEW program and not my power supply.
Here are the steps that lead to my problem:
1. In the block diagram, I insert a DAQ Assistant block.
2. In the Properies of the DAQ Assistant, I select Analog Input->Voltage
3. I select channel ai0
4. I click "test" in order to test the channel
5. The voltage is shown to be 1.43 Volts, even though 4 Volts is being supplied to the pin (this is confirmed with a multimeter).
6. To ensureI click OK to finish configuring the DAQ Assistant. I run the program and plot the voltage. The plot also shows 1.43 Volts.
Does anyone have an idea why this may be occuring. I've spent a good 4 hours trying to diagnose this and haven't found anything.
Thanks,
Abed Alnaif
Solved!
Go to Solution.

Thanks so much for your help. I used MAX, and found out that the issue
is that I had specified differential voltage, but I should have
specified RSE voltage.
However, now I have a different issue: When I apply a voltage to one pin, MAX also shows a voltage on other pins.
For example:
1. I apply a DC voltage of 4V to analog input pin ai0.
2. In MAX->Text Panels..., I select Channel Name = Dev1/ai0 and Input Configuration = RSE
3. I click Start, and the chart shows the correct voltage (4V)
4. I change the Channel Name to Dev1/ai1and Input Configuration = RSE
5. The chart shows a noisy voltage reading between 1.45 and 1.5 V, even though no voltage is applied to pin ai1
6. When I change the voltage on pin ai0 to 2V, the voltage reading on pin ai1 changes to 0.63V
7. Using my multimeter, I confirm that there is in fact 2V on pin ai0 and 0V on pin ai1
Does anyone know why applying a voltage to pin ai0 causes a voltage reading on pin ai1?

I have trouble reading a voltage across a FP-AI-102.

I have read a constant voltage across a voltmeter, yet when I plug into the FP-AI-102, the voltage jumps around. I have also tried changing the source of the voltage to a DC power supply, in which case the LabView software reads the voltage perfectly. I believ it is a problem in my programming. If you have any suggestions on a possible way to program the LabView to read the voltage, please let me know.

It sounds like your voltage is an AC voltage. Your voltmeter typically will employ an integrating ADC which essentially averages its readings to get a steady reading. If your signal is changing, similar to a sinus signal, you will see a changing voltage at the fieldpoint analog input level. Since the ai102 can scan its inputs at about 200hz or more (2.8ms), you get lots of voltages to work with. You can test this theory by putting your voltage on an oscilloscope.
So, in LabVIEW scan the voltages as fast as you can, and then either average, or better yet use a statistical median. I like the median as it is not affected by outliers.
I hope this helps.
Sincerely,
Preston Johnson
Preston Johnson
Principal Sales Engineer
Condition Monitoring Systems
Vibration Analyst III - www.vibinst.org, www.mobiusinstitute.com
National Instruments
[email protected]
www.ni.com/mcm
www.ni.com/soundandvibration
www.ni.com/biganalogdata
512-683-5444

How to read the power and status LEDs on cFP2020

Can the cFP2020 Power and Status LEDs be monitored by a host program? Also, can the Power and Ready LEDs be monitored from the other cFP Modules?

You can not directly read the Network Module Power or Status LED from a host program. Likewise, you can not directly read the Power and Ready LED of an IO module.
However, even though you can not directly ready the LED status, there are ways of finding out most of the information that the LEDs convey.
For the Network Module Power LED, you can infer the status of the Power LED by looking at the channel status for any/all items that are on the bank. If the items have errors indicating that a communication timeout has occured or an addressed item does not exist, then it is probable that the unit is offline (either because of no power or a fault). The Status LED indicates the current operating status of the Network module and in most cases, if it is flashing
, then a fault has occured that shutdown the processor. In most cases, you will not be able to determine that the Status LED is flashing, as the Status LED indicates a fault condition which will put the unit into a non-standard operating mode (e.g. firmware corruption, unassigned IP Address, or an OS fault).
For the IO modules, each channel on a module can report status, and based upon the status you can infer the state of the LEDs. If the module does not have the Power LED lit, the most likely status will be "Addressed item does not exist". If the module has the Power LED but no Ready LED, then the status will indicate that the "item is unconfigured". If the module has both a Power and Ready LED, than the channel should report either a good status, or a channel specific error (if applicable).
Regards,
Aaron

Scxi 1112 can not acquire correct data at high temperature(higher than 700C)

A scxi-1112 module in scxi-1001 chassis is used to acquire oven Temperature. Software is LabView 8.5. when oven is ramping higher than 700C, the module gets wrong data, the data acquisition VI shows random values around 700C.It seems the scxi-1112 module "reaches" its maximum setting, which actually is 1000C. Can Anybody explain what's happening to me? Thanks.

Hi gq,
Could you please provide a screenshot of the
way you are configuring the task, as well as what the data looks like
that you are seeing when it behaves incorrectly? If you just perform a
voltage reading (instead of a temperature task), what values are
returned, and does it show the same behavior of reaching a certain
voltage and not ramping any higher? Also, how do you have your
thermocouple attached to your oven; is there any possibility that the
connection is conducting at that temperature? Also, regarding the use of different measurements in the task, are you using different modules in your system or are the measurements being done on the same 1112 module? Additionally, have you tried other channels and received the same problem? I look forward to reading your response.
Regards,
Daniel S.
National Instruments

SCXI 1300 module

Hai,
I am using SCXI 1300 module to read temperature values using J type thermocouple. When I am measuring the room temperature, it is showing wrong value. (If the daisy chain index is changed from 0 to 7 , the room temperature differs) I need to measure the temperature of a hot plate. I am using 10 thermocouples. Please anyone help me.
Thank You.

Hi,
My first suggestion is to make sure you are connecting the thermocouple like we specified in page 7 of the SCXI-1300/1301 Guide and Specifications. My second suggestion is to make sure the scxi-1300 is selected as the accessory of your module, since this card has a built in CJC; you need to configure your system to know that. The name of the channel for the CJC is called cjtemp in the case you want to make mueasurment directly to it.
This is a discussion forum of another customer that had a similar issue, take a look at it and follow the conversation; this is a good reference on how a misplace jumper may make the card read the incorrect voltages. Voltage Measuring error in LabVIEW with scxi-1100/1300. Another very good reference is the article in DevZone How to Use Thermocouples with an SCXI-1102 Module
Where are you reading the voltages, test panel or LabVIEW?
I hope it helps
Jaime Hoffiz
National Instruments
Product Expert
Digital Multimeters and LCR Meters

Calibration of scxi-1112 channels simultaneously

can i calibrate all the channels in the module simultaneously using Scxi -calibrate vi if so please send me a example in lab veiw

Suresh,
It is not possible to calibrate all of the channels in the SCXI-1112 module simultaneously. However, it is possible to design a program which will calibrate every channel sequentially without having to manually update the SCXI channel string between each calibration run. Simply place the SCXI Calibrate VI in a for loop. Use the index of the for loop as the channel number and create the channel string dynamically. You can then pass this string, which will change each time around the for loop, into the SCXI calibrate VI.
Regards,
Justin Britten
Applications Engineer
National Instruments

How can I read the value of an SCXI-1124 channel in LabVIEW?

Is there any way to read back the value of an output channel of SCXI-1124 in LabVIEW (version 6.1 or 7.0)? I want to sweep the output gradually, and want to avoid a sudden change. But this is difficult if the current status of the channel is unknown. Especially, when the computer is reset or shut down, the SCXI-1124 maintains the output voltages (which is good for my application), but I have no idea what those values are.

If I understand, you can look in the MAX. Then, in the pheriferal you can find the Ntional Instrument Card inserted into the PC. When you test this card you can read the input signales of the card( Volt in general)which is the out put of the SCXI.
regards
Anwar

During continuous scanning thermocouples with a SCXI 1120 module is the cjc reference read each scan?

Did the developers of the DAQmx drivers improve the temperature scan capability of the SXCI 1120 module over the methods used in the traditional drivers?
When using the SCXI 1120 module for temperature measurement and in the continuous scan mode with traditional drivers the cold junction reference was only checked on the initial start of the scan. In order to maintain accuracy it was necessary to restart the scan.
For the most part I have switched to the 1125 module for thermocouple measurement but I need to use some 1120 modules on a test stand now and I will be using the DAQmx drivers on these. I was in hopes that with the DAQmx drivers this behavior was corrected.
I can conduct testing to determine this but would like to know ahead of time if this is still an issue.
Thanks

Thank you Ben for the answer.
I checked the article you referenced appears to me that I will be adding the physical address in the channel strings then do the voltage to temperature conversion and then correct the appropriate channels associated with the cjc in question. I will also need to adjust some on board jumpers for the SCXI 1120. If I am wrong please correct me.
If scanning the physical channel is possible as suggested in this article, would it not be possible to create the channel as a virtual global channel and reference it as the cold junction in Max? Then the temperature adjustment could be done at this level of acquisition rather than having to sort this out in the LabVIEW program. This takes me back to the days with LabVIEW 4.0 before we had the virtual channels and when we had to handle the temperature conversions and other scaling ourselves. Again if I am incorrect please let me know, for I would like to use the method recommended in the article if I don't have to perform all the calculations in the application.
Just wondering if anybody reading this has actually used this method. If so, how did it work for you?
I may end up building a start up routine testing for 1120 modules being used for thermocouple measurement then if found run a stop and restart scan every 5 minutes to prevent large errors from being introduced.

Read the voltage of CJT thermistor in SCXI 1112 module, revA

Similar Messages

Maybe you are looking for