Communication stucks with Ketihley 2700 data logger

[LTBALAZS]

Hi, 

I've been facing a technical issue with Keithley 2700. Communication lost occurs after hours of data acquisition:


Even if i stop the .vi and restert it I cannot have communication with Keithley 2700. I must restart my PC all the time in order to the communication be fine.

I use 1m long RS-232 cable.
Have you got any ideas please?

Kind regards,
Balázs

[GerdW]

Hi Balazs,

do you get an error after more than 9½ hours?

[cstorey]

Showing some code *might* help.  

Are you using a USB-RS232 converter or a straight RS232 cable with a dedicated serial port on a PC?  If USB is involved look at your PC power settings and disable the USB selective suspend setting - https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z000000P7POSA0&l=en-CA

Craig

[LTBALAZS]

Hi,

I apologize for the late reply. 
Let me answer your questions:

- Error code 85 can occur any time and pops up (refers to) the following VI:

Error 85
When i stop the data acquisition after error 85, i get another error code as :-1073807339

- I am using straight RS232 cable with the lenght of  about 1m. Note: Error 85 occured also when i was using USB to RS232 adapter.
I attached the simplified VI that i use in my project.

Can you find some bug to be fixed in my code?

Kind regards,
Balázs

[GerdW]

Hi LTBalazs,

error 85 is from ScanFromString: the received string doesn't fit to the scan format string…

All you need to do is to handle the error: right now there is no error handling at all!

---

@LTBALAZS wrote:

When i stop the data acquisition after error 85, i get another error code as :-1073807339

---

This is a TimeOut error, probably due to not handling the serial port correctly…

The loop of your VI can be simplified like this:

What's the point of calling the Close (and Error handler) function after the loop when the loop never will stop?

Use a boolean button instead of this FALSE constant!

[LTBALAZS]

Hi GerdW,

After the failed communication with Keithley 2700, I stopped the vi and started it again. I then got the following error:
Error code: -1073807339

This is something that cannot be solved by restarting the vi or quitting labview and powering off/on Keithley.
I have to restart both: the PC and Keithley to start data acquisition with keithley again.

Do you think i can manage this phenomenon in labview in run time? How?

Kind regards,
Balázs

[GerdW]

Hi Balázs,

which kind of RS232 port do you use?

Directly on PC motherboard, PCI(e) expansion card, USB-to-RS232 converter?

[LTBALAZS]

Hi GerdW,

It is RS232 connection on PC motherboard. 
I tried to plug the rs232 cable to another RS232 socket, but error still occured:

'Error -1073807339 occurred at VISA Read in Keithley 27XX.lvlib:Error Query.vi->Keithley 27XX.lvlib:Error Query (Multiple).vi->Keithley 27XX.lvlib:Configure Scan.vi'

Then plugged the rs232 connector back to its original socket. Result: Connection is OK.

It seems to me that the connection 'hangs' after some time.

Kind regards,
Balázs