Problem: Instrument via serial connection

[pclab]

Hello Forum,

I am trying to connect my instrument to my laptop via USB through Serial port. I used NIVISAIC and found the Resource name as ASRL3::INSTR. When I was working with Laview I found the following error

Error 1073807246 occured at property node (arg1) in VISA configure serial port (Instr.). Reason: The resource is valid, but VISA cannot currently access it.

Using the interactive control one of the attribut is in red (Is Port connected: VI_ATTR_ASRL_CONNECTED: Invalid property value

Also when I send Identification query using NIVISAIC, it returns the same command.

I did not understand much of it. However there is a software for the instrument, using which I could connect to the instrument the first time I switch on the system. When I disconnect it and tried once again, it was not connecting.

I had earlier connected Keithley 2400 via GPIB KUSB 488. Is there any problem in connecting two devices. Or is the driver of the software and NIVISA are conflicting with each other.

Please find the screen shots.

Please help.

Thank you.

[Dennis_Knutson]

First, ignore the property error. That is only for NI USB-RS232 converters. Second, windows does not allow more than one process to access a serial port at a time. So, your software from the vendor should not be run at the same time. Third, check for proper termination character. You may have to send a \r or \r\n.

[pclab]

Hello Dennis,

It did not help much.

7: Write Operation (*IDN?)
Return Count: 5 bytes
8: Read Operation
Return Count: 5 bytes

*IDN?

I tried to query with \n and \r\n; but did no good. There is only one instrument connected to the PC via Serial port.

I would like to know if the identification command is same for all instrument or does it change with manufacturers.

Why does it return the same command that was given to the instrument.

If I am to ignore this, please find the block diagram and manual of the instrument in the attachment. It was said that the commands should be sent as single characters and not as string.

In the block diagram I have used VISA Configure Serial Port, VISA Write, VISA Read and VISA Close vi's. Please tell me whether this is correct. The Commands where given in separate lines or should I use separate VISA Write vi for each characters.

Thank you.

[crossrulz]

Not all instruments follow the SCPI standard.  In SCPI, *IDN? will have a response to identify your intrument.  I didn't see anything like that in the manual.

[Bharadwaz]

Hello.

The possible reasons could be

1.Serial Cable (what type of serial cable you are using)

2.Check the serial settings on the instrument and on your LV (Baud rate , Stop bits etc) are thwy matching..!?

3.If your device has an Indication that it is going into remote mode when running your application and yet you do not get any response
then it can be an issue with your protocol (termination character , chcksum etc)

4.Do not run application provided by the instrument , VISAIC and LV simultaneously.

4. and yes as Ben said ignore the property invalid thing.

[TommyWei]

I am also trying to use LabView to control PR-655. Did you figure out how to do that?

Thanks,

[kian666]

I have a fiber optic switch (LEONI), it has 3 input channels and 1 output and serial port interface.  anyone has an example of how should i operate it in labview? I know very basic things about Labview

[nyc_(is_out_of_here)]

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@kian666 wrote:

I have a fiber optic switch (LEONI), it has 3 input channels and 1 output and serial port interface.  anyone has an example of how should i operate it in labview? I know very basic things about Labview

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There are serial communication examples in LabVIEW.

Don't post multiple times about the same topic.