Error 1073807246 after connect datalogger with computer

[hftuo.xjtu]

I have labview vi for getting data from datalogger.

Firstly,  it is excutable without error

, but when datalogger is connected to computer(serial port COM1), my labview vi shows the  Error 1073807246. 

I know a little about this error, it means open a visa that has been opened, but donot why error occurs when datalogger connect with computer. 

I just copy this labview vi from previous lab computer, it did work well on that computer. 

many thanks for any help.

[dan_u]

As the error states, open your serial connection just once. You get this error if you try to open a serial connection that has been opened already. See here.

It looks like you have a loop around your code. If this loop executes several times either open the serial connection outside the loop or make sure you only open it at the first loop iteration.

Also make sure the serial port is not used by some other application like teraterm.

[hftuo.xjtu]

thanks

I check, no other application uses serial port.

The error always occurs once the serial port is connected to datlogger, otherwise, this vi is ok.

the datalogger I use is Campbell Scientific R23X, and supporting software is PC200W, I donot know that could be problem or not, in my precious pc, PC208W a different version supporting software is used.

many thanks for any help

[Dennis_Knutson]

The error does not mean another VISA session is open. If another VISA session was open in LabVIEW, you would not get an error. Windows is blocking the LabVIEW program. Try to open the com port with Hyperterminal. If another app is using the port, Hyperterminal will also return an error. Besides regular apps, you should check the windows services. What is this 'supporting software' you mention? If that is a program that came with the instrument, my guess is that is running.

[hftuo.xjtu]

Thanks Dennis, I try to state my problem and instrument I use as clearly as possible.

supporting software is for datalogger, I use this software to connect my datalogger with PC(please see image), otherwise  my labview file cannot read any data from serial port.

 

But it looks like, once datalogger is connected to COM1 port, labview file error occurs when I run it.

these datalogger and labview file did work well on previous PC, the only difference I think is the way how datalooger is wired to PC port. on older pc, datalogger RS232 port connecting to PC com port firstly by common 9-pin wire and then self-made 9-pin wire which connect to both pc com1 and com2 port. on new PC, I just directly connect datalogger with PC by this white 9-pin wire. 

 

I donot know whether this will cause errors, I read old thread, some one has the same error for his iv, but finnally he found out the straight throught cable he used causes this error, he changed to crossover cable, it is ok.

[Dennis_Knutson · Accepted solution]

It's pretty clear that you have some major, major misconceptions. The software from the vendor is not required for a LabVIEW program and in fact is causing the conflict. Windows will not allow more than a single program access to com ports and as long as you remain convinced that you have to keep running that program, the LabVIEW program will never run. The other pc is certainly set up to use one com port for that program and one for LabVIEW.

If in fact the other program is required, then the LabVIEW program was not written to be a complete control program.

Message Edited by Dennis Knutson on 03-13-2010 06:12 PM

[hftuo.xjtu]

Many thanks for your help.

Now I can understand why two com port in previous pc and that self-made wire were used. datalogger is connected to COM1, and by that self-made wire, data at the same time also transmit to COM2 for labview to read, I think that should be how they work on previous pc.

Thanks very much again.