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astroboy
Posts: 402
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Simple serial loopback test

Hi. I have been reading more info about the use of serial port in my PC.
Using the Hpyerterminal program, I am able to get response using the loopback test as instructed from NI website's tutorial.:smileyvery-happy:
 
Now I proceed to use the LabVIEW <-> Serial.vi from the provided example in my Labview Development Software.
Again I use the loop back to read the sent string. Somehow, I got errors when performing it for the first time.:smileysad:
I could not find help from the Labview software or forum here. :smileymad:
There are two things in the LabVIEW <-> Serial.vi which I cannot understand.
They are : resource name (Control) and VISA Configure Serial Port.vi. That error comes from VISA Configure Serial Port.vi.
The error is "Property Node in VISA Configure Serial Port (Instr).vi->LabVIEW <-> Serial.vi"
 
So how do I solve the problem?
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Electro_gab
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Re: Simple serial loopback test


1. The resource name control is where you choose your serial port: com1 , com2 ...

2. Visa conf. serial port is where you set the  parametters  of  the port : baud rate, parity, flow control...

For your error, it might comes from the fact that the port is currently busy.

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astroboy
Posts: 402
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Re: Simple serial loopback test

Hi thanks. But the hyperterminal program is closed,  meaning that the serial port is now closed.

There are no other programs using the serial ports

How do I find out  if one  or all  the serial port is busy?

Cheers:smileyvery-happy:

 
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Electro_gab
Posts: 15
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Re: Simple serial loopback test

Is "resource name" control pointing to an available port on your machine? Try opening the port on wich "visa conf. ser port" hung in hyperterminal to see if it is busy or not. Also, try telling the program to continue on the error pop-up dialog, to see if execution will continue normally.

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Dennis_Knutson
Posts: 33,556
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Re: Simple serial loopback test

What is the actual error number that is being generated? That's an important piece of information you need to provide. Also, attach a picture or the VI with the actual settings you're using. If you post a VI, if you're using front panel controls to set the parameters, be sure to first select Operate>Make Current Values Default and then save it. There's an awful lot of possible causes for an error and the more information you provide, the quicker a solution can be found.
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astroboy
Posts: 402
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Re: Simple serial loopback test



Dennis Knutson wrote:

What is the actual error number that is being generated? That's an important piece of information you need to provide. Also, attach a picture or the VI with the actual settings you're using. If you post a VI, if you're using front panel controls to set the parameters, be sure to first select Operate>Make Current Values Default and then save it. There's an awful lot of possible causes for an error and the more information you provide, the quicker a solution can be found.


Electro Gab wrote:

Is "resource name" control pointing to an available port on your machine? Try opening the port on wich "visa conf. ser port" hung in hyperterminal to see if it is busy or not. Also, try telling the program to continue on the error pop-up dialog, to see if execution will continue normally.

Hi. Dennis and Electro gab,
 
Here is a pic of error msg, and there is a vi for you to try it out.
 
The resouce I am pointing to is Com 1. I cannot continue the program after the error. I set the "select type" of VISA configure Serial port to automatic. But I am not sure about the "VISA Resource Name" Control's Select VISA Class > IO Session >Instr. Is Instr correct. Must I have NI VISA Driver?
 
Cheers :smileyvery-happy:
Clement
 
Active Participant
Chris_R.
Posts: 408

Re: Simple serial loopback test

Hello,
Yes, you do need the NI-VISA driver.  The page is linked below with a KnowledgeBase about that specific error you are getting.  I hope this helps!  Have a great day!

Chris R.
Applications Engineer
National Instruments

http://digital.ni.com/softlib.nsf/MainPage?ReadForm&node=132010_US
http://digital.ni.com/public.nsf/websearch/6055CCB1C032D1DD86256C32004EC84D?OpenDocument

Chris R.
Applications Engineer
National Instruments
Knight of NI
Dennis_Knutson
Posts: 33,556

Re: Simple serial loopback test

As mentioned, the error code indicates you don't have VISA installed. The description for the code is installed along with VISA. So, if you have VISA installed, you won't get the error, but, if you don't have VISA installed the description won't exist and you don't know what's wrong. I hope that in the future, NI can include this description in the LabVIEW installation.
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astroboy
Posts: 402
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Re: Simple serial loopback test

Hi Chris and Dennis, Thanks. It works and I just realise.
Thanks