04-24-2012 07:41 AM
I use Etherwan SE6300 converter and Wi-fi router to communicate with my device (it has RS422 port).
Device works in slave mode, i.e. waits for request packet and then responds with data packet.
My software polls device periodically to display it's state.
During several tens of seconds all is OK.
Then I get Visa Read Error when waiting for reply. At the same time I see that corresponding request reaches the device by blinking Tx LED.
After 5 read errors connection goes off and Visa Write also starts to fail with -1073807194 error.
Now Tx LED stops blinking.
Timeout is set to 3 seconds.
If I use cable instead of Wi-fi, all works good!
Connection can be recovered by closing and re-opening Visa session, but that's only a workaround.
What can be the reason of getting read errors?
07-17-2012 10:09 AM
Most likely the issue here is the wireless network being unstable. VISA might be picky on how many packets it can lose due to the network. Have you tried to increase your timeout? Can you put the devices closer to see if the signal strength improves the communication?
07-18-2012 10:30 AM
Are you able to communicate with this device using other software (always over wi fi)? I see that the SE6300 has several operation modes. Have you tried changing those parameters?