I'm trying to port my Labview 8.2 application from Windows XP to Red
Hat Enterprise Linux WS release 4, kernel 2.6.9-11.ELsmp.
It communicates to a Tektronix TDS2024B oscilloscope through the VISA 4.0
interface and works well under Windows XP. However it doesn't work
under Linux.
The oscilloscope is seen by both the visaconf and the NIvisaic (Interactive
Control) under Linux. I tried to communicate to the scope through
NIvisaic under Windows XP and Linux and it's here where I already see
the difference. I did two identical procedures under XP and Linux:
1) Start NIvisaic
2) Open (double click) the scope which is seen as
USB0::0x0699::0x036A::C031476::INSTR
3) Write "*IDN?/n" with an viWrite Tab
4) Read the response with viRead
In the case of XP all steps are success and I read back
TEKTRONIX,TDS 2024B,C031446,CF:91.1CT FV:v22.01\n
In the case of Linux steps (1) and (2) seem to go well, but (3),(4)
return with an 0xBFFF0015 error, which is timeout out expiration.
I tried to increase the timeout up to 10sec (viSetAttribute Tab seems
to work fine) it didn't help. I worked under root account on the linux
system and usb file system was mounted.
My next step was installing the latest VISA 4.2. The installation
process was reported to be successful, but I'm having all exactly the
same problems when trying to communicate to the oscilloscope.
Thanks in advance for your help.
