INSTRUMENT I/O ASSISTANT EXPRESS VI - PERFECT PARSING NO OUTPUT

I am using the Instrument I/O assistant express VI to parse data from a (visa) serial port. Neatest thing since sliced bread! I initially send a write command followed by eight read/parse commands to retrieve eight tokens each ending with cr/lf. All seems well during i/o setup. The Vi compiles and shows all eight string tokens. I then connect each one to a string indicator. When the Vi is run no data appears in the indicators. Repeated runs during the I/O setup shows tokens extracted perfectly. What's going on?

Hello oledaqman,
I tried to replicate the problem you are seeing, but everything seems
to work fine on my system. One option I would propose would be to
use NI-SPY to determine if the reads are actually being performed when
you run the VI. NI-SPY should allow you to determine if the VISA
commands inside the Express VI are being executed, as well as
determining whether they are receiving any data.
This will help us to determine whether the problem lies in the actual
transmission of the data, or the parsing of the data after it is
received.
Let us know what you find, or if you have any questions, and we will be happy to help.
Jason S.
Applications Engineer
National Instruments

Similar Messages

Instrument i/o assistant express

hi, i hav all ready installed the driver cds along the the labview7.1 software but i m not able to use the instrument i/o assistant express in my application then plz guide me how can get it.

Could you give us a little more information? Can't use, how?
Do you have the Instrument I/O Assistant Express VI?
Can you drop it?
Can you configure it?
Does it then fail to operate ase configured?
Where in the chain of use does it fail?
Thanks,
Bob Young
Bob Young - Test Engineer - Lapsed Certified LabVIEW Developer
DISTek Integration, Inc. - NI Alliance Member
mailto:[email protected]

Can I use the instrument I/O assistant express vi to communicate with a USB connected instrument ?

Can I use the instrument I/O assistant express vi to communicate with a USB connected instrument ? My PC is running Windows 2000 et Labview7 express.
where can I get information or examples on the assistant and USB communication ?

Yes you can - the Instrument I/O Assistant communicates with message-based instruments through VISA. VISA 3.0 supports USB instruments and VISA 3.0 is the version of VISA that installs with the Assistant.

LabVIEW 7.0 Crashes when inserting "Instrument I/O Assistant" Express VI

Hi,
I'm unable to work with Instrument IO Assistant when ever i try to place the IIOA express vi on the blockdiagram a message pops up saying "MAX or IIOA is not installed correctly please install from NI driver CD". Also i've not installed NI-DAQ/mx on my PC.
I tried to install from IIOA.msi but the problem remained & also tried install/uninstalling MAX & IIOA many times but didn't work.At present i don't have Driver CD as well.
Plz help me out.
Thanks
sayaf

Sayaf,
Do you just get this message about IIOA not being installed correctly? Or does LabVIEW actually crash as the title of your post suggests? At what point does LabVIEW crash?
As far as the message goes, there are a couple of things to check:
1) Look under \vi.lib\ - is there a directory there titled "InstrIOAsst" with IIOA.LLB inside the directory? If this file is not there, then this is the source of the message you are receiving - I can help you get this straightened out if this is the problem.
2) If that file is present, then check your \Shared\ - is there a "LabVIEW Broker" directory there? If so, confirm there are two files present in that directory: LVBroker.dll and LVBrokerAux70.dll. If these files are not present then this could cause that message to show up as well.
-Tommy

Instrument I/O Assistant Help - Parsing Errors

Hello All -
I am having trouble working with a TSI DustTrak DRX - which does not have its own driver so I had to make one. At this point, all I want to do is send a command to the instrument and get an indicator to repeat what the output is. So far no luck.
1) I think my driver works. The instrument is connected via ethernet. The instrument has a static IP. In MAX when I look under "Network -Devices" it appears there. "Validate" results in a successful connection. If I click on "Open VISA Test Panel/Input/Output" I am able to enter commands (e.g., rdmn\r returns the instrument number) and "Query" and the correct answer comes up. It should be noted that the number of bytes returned for different commands are different, and also that the measurement data is always of variable length, so I often get the "Timeout expired before operation completed" error. For a simple read instrument number command, the number of bytes is predictable, but for the measurement data, it is not, unfortunately.
2) When I put an "Instrument I/O assistant" on the block diagram of a new VI, and add a "Query and Parse" step with the same command (rdmn - no \r this time), I again get the expected value (or when I query the measurement, rmmeas, I get the expected output string). Again, it should be noted I get the "Timeout expired before operation completed. VISA Status code : bfff0015" error. Once I close then reopen the Instrument I/O Assistant configuration window (though not before) I can parse the data, and the token appears as a potential output of the VI. Here I can declare the output as either String or Number.
a) If I declare the output as a string and create a string idicator, an empty string is returned.
b) If I declare the output as a number (it is "8533", so this should be OK), I get the following error (even without creating an indicator before running): "Error 1 occurred at Scan From String (arg 1) in Untitled 5:Instance:0->Untitled 5 Possible reason(s): LabVIEW: An input parameter is invalid. For example if the input is a path, the path might contain a character not allowed by the OS such as ? or @." I know from MAX that the returned value is actuall 8 bytes: \r\n8533\r\n . So, there are no unallowed characters here. And there are no paths involved - no read/write.
Some other info:
1) If I send start or stop commands to the instrument in MAX or the Instrument IO Assistant, I can get the instrument to turn on/off as it should, so I'm clearly comunicating to the instrument correctly.
2) I get the same behavior if I parse the returned measurement string - \r\n385,0.013,0.014,0.015,0.020,0.035,\r\n from MAX - as a set of numbers (that is, with "Error 1 occurred at Scan From String (arg 1) in Untitled 5:Instance:0->Untitled 5 Possible reason(s): LabVIEW: An input parameter is invalid. For example if the input is a path, the path might contain a character not allowed by the OS such as ? or @.")
Any help would be appreciated!
Thanks.

Hi James - Thank you very much. I actually found the problem and was able to fix by changing how the output text was parsed - the \r\n in front and back was confusing it - and making sure that I flushed the read buffer after reading, just in case. I also had to modify so that the first character was read and discarded before reading (and using) the rest of the output string.
Now for a rookie question: I've got it set up as a working VI now - how do I declare which variables are inputs and outputs when I put it in another vi?
Thanks.

How to send multiple commands throught the Instrument I/O Assistant

I am using the Instrument I/O Assistant to set up an instrument driver. I am only using two rs 232 commands. The way I have the Instrument I/O Assistant setup is: first I have a default instrument setup step then I use a write step with the first command, then I read and parse, then I do a write command again with the second command and finally I read and parse again. All of this works fine inside the window but when I run it in my program only the first command's response it outputed . The second command's response is not outputted it just sends a null. Can the Instrument I/O Assistant only handle one read and write, or is my logic wrong?
Thanks for your help
Ian

Hi Ian,
You should be able to perform multiple reads/writes with the Instrument IO Assistant. What termination character are you using? I have seen cases where different termination results in different parsing, which may explain why you're only receiving a null character on your second read. Thanks!
Regards,
Anna M.
National Instruments

Instrument I/O Assistant RS232 communication problem

Hello!
I am currently trying to create an instrument driver for a Ballard "Nexa" fuel cell with the Instrument I/O Assistant.
The fuel cell data is 43 byte sent every 200 ms at 9600 Baud (8N1). I do have a working communication, because I can see the data coming in when I´m using an ordinary terminal program. The Instrument I/O Assistant however does not seem to receiver anything.
Here´s what I do / what I see:
Create an empty VI
Place an "Instrument I/O Assistant" block on the block diagram, the Instrument I/O Assistant windows pops open.
Choose device: COM1 or COM2, depending on where the Nexa is connected (Choosing different devices has no influence on my problem)
Add step "read and analyze"
Click "Run this step" to read the data coming in from the serial port, but nothing happens until the the timeout set on the choose device tab has expired, then I get a timeout message (see attached picture).
I added a RS232 diagnostics plug that has blinking LEDs while data is flowing to make sure there is data coming in while the assistant is running.
I a previous thread, I read that the Instrument I/O Assistant has a bug concerning the locale settings of windows:
http://exchange.ni.com/servlet/ProcessRequest?RHIVEID=101&RPAGEID=135&HOID=5065000000080000002DBF0000&UCATEGORY_0=_49_%24_6_&UCATEGORY_S=0&USEARCHCONTEXT_TIER_0=0&USEARCHCONTEXT_TIER_S=0&USEARCHCONTEXT_QUESTION_0=Instrument+I%2FO+Assistant+is+not+communicating&USEARCHCONTEXT_QUESTION_S=0
So I tried the same after switching my locale settings from german to english, but with no success, the I/O Assistant still seems to see not input.
Does somebody have another s
uggestion? Has anybody written a serial read/parse VI from scratch that he/she might share so I can use that as a starting point, if the assistant keeps failing for me?
Thank you,
Ingo.
Attachments:
errormsg.gif ‏5 KB

Hi TN,
As I just started using LabVIEW, developing an instrument driver seems like some pretty heavy stuff. For now, I´ve managed to have someone else write the communications backend, I´ll only do the data conversion and display. But I´ll for sure take a closer look at that communications VI so I ´ll get it done myself next time...
Anyway, thank you for your reply, I appreciated it.
Ingo.

Instrument I/O assistant error msg "Unable to view proterties"

Hi, NI's AE,
I have re-installed many times NI LabView8.2(EV) + DAQmx8.3 on all
in one SOC platform(X86) with WinXP(SP3) step by step, but all
rebooting fail after DAQmx8.3 installed.
Then I re-install pure WinXP(SP3) + LabView8.2(EV) + DAQmx8.9,
rebooting ok.
LabView simulated VI from template works well, however I got error
"Unable to view properties" when I drag & drop "DAQ Assistant"?
After google the related issue of "Instrument I/O Assistant error".
I check the "Add/Remove S/W List" and "System Services" of window,
everything seems ok.
Attach file description :
    Add_Remove_List.jpg -
        No extra software installed, except NI's S/W.
    Add_Remove_NI_List.jpg -
    The key drivers, NI Instrument I/O Assistant & NI-VISA 4.0 &
        NI-488.2.2.46 all be installed well.
    NI Service List.jpg -
        NI's related service be well active.
    Instrument IO Assistant - Unableto view properties error.JPG -
        Drag & drop "DAQ Assistant" VI, popup error dialog box
        "Unable to view properties", not "Create New Express Task"
        form.
Is there any compatible issue between LabView8.2 & DAQmx8.9 ?
B/R
Hank

Sorry, forget attach file!
Attachments:
Add_Remove_List.JPG ‏99 KB
Add_Remove_NI_List.JPG ‏132 KB
Instrument IO Assistant - Unableto view properties error.JPG ‏77 KB

Instrument I/O Assistant Crash

I am using Instrument I/O Assistant to read data from a scale through a Serial->USB conversion, using LV2012 SP1 (I've also tried this on LV2010 with the same results).
I configure the baud rate, parity bits etc, and that seems to work fine.
I add the "Read and Parse" step or a "Query and Parse" step, and then try to run the Instrument I/O Assistant. The Instrument I/O Assistant window closes. It doesn't throw an error, or a warning or anything.
Needless to say, the vi where I use the I/O Assistant does not run either.
Any thoughts as to why this is happening?
Attachments:
Scale.vi ‏39 KB

Personally, I think not having the assistant is not such a bad thing. What happens when you use the simple serial example? What sort of converter are you using (ftdi, etc.)? What os and version of VISA?

Instrument I/O assistant configuration dialog box does not appear

Hello,
In the function pallette both input and output subpallettes have instrument assistant express vi.But, when I put in the block diagram window Instr I/O assistant configuration dialog box doesnot appear.I double clicked instr assistant icon but it did not work. Labview version is 7.1.Does anyone has clue to overcome this problem?
Phylab
Solved!
Go to Solution.

Hello phylab,
The Instrument I/O Assistant (IIOA) is used for easily communicating with GPIB instruments in Labview. For Labview version 7.1, the IIOA is available on the shipping reference driver CD. It should be automatically
installed when you're prompted to enter the driver CD, through setup.exe. Is this your first time using it or has it worked in the past? Do you also have the NI-VISA and NI-488.2 drivers? And you installed the LabVIEW cd before the driver cd, correct? The fix should be to uninstall and reinstall IIOA from the device driver CD.
Regards,
Deborah Y.
LabVIEW Real-Time Product Marketing Manager
Certified LabVIEW Architect
National Instruments

I do not see the DAQ Assistant Express on Functions Input palette.

Software config: Windows XP machine, Traditional NI-DAQ 7.4.4 for PCI 6602. I do not see the DAQ Assistant express on Functions>>Input palette. I get error message when I place the Instrument I/O assistant on the block diagram:-" Measurement and Automation Explorer or Instrument I/O Assistant not installed correctly. Please install from LabVIEW CD". I've tried uninstalling, re-installing driver and rebooting my computer several times.

Hello PJ-SJM,
The DAQ Assistant Express VI installs with the NI-DAQmx Driver and not Traditional NI-DAQ. The good news is that the PCI-6602 is supported in both Traditional NI-DAQ and NI-DAQmx. Check this KnowlegeBase article to find out what version of NI-DAQmx you need and then search the Drivers and Updates page for to find the version you need. Once you download and install the driver you should see the DAQ Assistant Express VI on your functions pallet.
The Instrument I/O Assistant is not for use with DAQ cards, it is for using other communication protocol like serial or GPIB. However, if you need this you can install the Device Driver CD and it should work after that. Note: The device driver CD that came with LabVIEW should also contain the correct version of NI-DAQmx.
I hope this helps, and have a great Friday!
Brooks

Instrument I/O Assistant returning delayed/slow response?

Hi there,
I'm somewhat new to LabVIEW 7.1 - I'm trying to make a simple program that reads and parses data over a serial line then plots it.
I created a small program which connects the output from the IIOA to waveform charts. I've read that the waveform charts plot the data points when the data is received, but when running the program, the chart updates with a new data point at 1Hz, yet my data is being sent at ~10Hz.
I opened the Front Panel for the IIOA and ran just that .vi, and still, the data updates very slowly.
Can someone offer me some insight regarding this problem?
Thank you,
Stefan

Hi Stefan,
If you have opened the front panel for the Instrument I/O Assistant,
and the data still updates slowly, then it is likely that your
instrument is taking longer than you think to respond? I would
recommend that you run NI-SPY while you are performing your
acquisition. In NI-SPY, you can double click on any of the driver
calls and see how long the command took to execute. This will
allow you to determine whether there is a long delay inbetween two
commands, or if the read command is taking a long time to
complete. I suspect that you will see that the read command is
waiting a while before it actually receives the data and is able to
return.
Let us know what you are able to find with NI-SPY, or if you have any more questions.
Jason S.
Applications Engineer
National Instruments

How do I program Instrument I/O Assistant to read a variable in the input string?

How do I program the Instrument I/O Assistant to read a variable in the input string? I can manually type in the string using the Instrument I/O Assistant using the "Write" or "Query" tools but I do not know how to send a variable input to the Instrument I/O Assistant so that variable can be used inside the "Write" string. For example, I have a power supply whose current I want to set to X Amps. I can type the command "PC10" to program the current to 10 Amps, however I want to be able to program it at any arbitrary current. How do I feed the value X into the code for this purpose?

You can't. The assistant was designed to be a quick and dirty way to do some basic communication with an instrument. You can turn it into a VI (right click and select Open Front Panel) and modify it so that your write string is an input to the VI or use it as a template and create your own code with VISA Read and Write primatives.

Instrument I/O Assistant problems

Hi,
I am having trouble using the I/O assistant through my parallel port. It is not writing to it. The VI example, Parallel Port Read and Write Loop, works just fine. Is there a way to use the I/O Assistant instead?
Thanks,
Ryan

Hi Ryan,
What sort of problems are you having? You should be able to use the Instrument I/O Assistant to communicate through the parallel port. This tutorial, Instrument Control in LabVIEW Tutorial, shows how to set up the I/O Assitant. If that's not working properly, what errors are you seeing? Have you run NI-Spy to see where those errors are occuring? Are you sure that you are sending the correct termination?
Let me know if you need any other help,
Meghan
Applications Engineer
Message Edited by Meghan R on 07-10-2007 02:26 PM

Instrument I/O Assistant (sending command from labview to arduino)

Hi,
I am a beginner in Labview. I would like to control the intensity of AC loads using labview. In this case, i would prefer to use instrument I/O assistant. The instrument I/O assistant in labview will have to send a command to Arduino. The intensity will be controlling by using slider in labview. How to write the vi for this example? Please advice.

feliciacpw92 wrote:
Hi,
I am a beginner in Labview. I would like to control the intensity of AC loads using labview. In this case, i would prefer to use instrument I/O assistant. The instrument I/O assistant in labview will have to send a command to Arduino. The intensity will be controlling by using slider in labview. How to write the vi for this example? Please advice.
In the thread for your other post, you were told that LabVIEW installs by default example programs on how to use LabVIEW with serial port.
Have you bothered looking at that?
You need to do some work on your own.

INSTRUMENT I/O ASSISTANT EXPRESS VI - PERFECT PARSING NO OUTPUT

Similar Messages

Maybe you are looking for