We randomly get the "specified Group is in use" error message when using the DIO Buffered Handshake In VI. How do we get rid of this?

Question

We're using the DIO Buffered handshake in VI (PCI 6503 Board) to read TTL pulses from a wavemeter. Sometimes we are able to collect data, but sometimes we get this error message: "specified Group is in use". No matter how long we wait between taking data, we sometimes (yet not always) get this message. We have one group of 2 ports that we're reading. Is there a way we can get rid of this problem?

Answer 1

Hi,
Are you running any example program or your own?
1. This problem happens when you abnormally terminate the program, such as, by clicking on the abort button.
Say first time you run the programd and it runs fine and then abort the program. In that case, the DIO group is not cleared and hence the subsequent runs give the error that you said.
In such case I would suggest you to open the Device Reset.vi which is under Functions Pallete>>Data Acquisition>>Calibration and Configuration>>Device Reset.vi.
On the front panel of the Device Reset.vi, enter the device number of your card and run the Device Reset.vi. If you get an error on the front panel, then run again so the error goes away. Now run you DIO program and it should run fine.
The botto
mline is, dont abort the program. If it has no functionality incorporated to stop it depending on some condition, then incorporate it.
Please do let me know if my suggestion helped.
Sincerely,
Sastry V.
Applications Engineer
National Instruments