I am using an old version of the ni 488 driver on a red hat 4 Linux machine.
We have a 5 GPIB instruments connected to the a NI PCI-GPIB controller card. This system was working ok until recently, when we started noticing the following behavior. The sequence of commands to the gpib chain is as follows:
1. ibsic to the gpib controller
Returns 480 or 496 intermittently. (Is this an issue? Seems like it is the talker flag that is intermitten)
2. ibclr to the gpib instruments
Returns 0x8000 (error flag is true), and the error is a timeout error
3. ibrsp
Returns 256
4. ibwrt *IDN?
5. ibrd
We are able to read back "IDN?" from the instrument just fine after the timeout error. Also, if we open communication with any individual instrument at a time, sending ibclr works, but it stops working as more instruments are opened. Any suggestions would be very much appreciated!!
