Technical data
66 Agilent Connectivity Guide
3 Connecting Instruments to GPIB
When the IRQ is asserted, the OS calls each ISR in turn until one of
them returns TRUE (meaning that it handled the interrupt). The
ISR’s responsibility is to correctly return TRUE if its device was
interrupting or FALSE if not. Drivers that return TRUE, even though
they did not service the interrupt, will cause problems. Try the
following steps:
• Upgrade the drivers for devices sharing an IRQ with Agilent,
including, but not limited to, your video drivers, your LAN
drivers, Agilent IDE and/or SCSI drivers, and your sound drivers.
4
Reconfigure Your PC. Configure your PC so as to not share IRQ lines.
Many PCI cards have bugs when sharing IRQ lines. You may or may
not be able to do this on all PCs. Many PCs can be configured using
the setup option when the PC is first booting.
5
Upgrade your system BIOS. New computers may have a newer BIOS
available. When installing a new system BIOS:
6 Make sure the BIOS
Installed O/S setting is set correctly. This
determines what software will configure all the VXIplug&play cards
in your system. Either the BIOS or the O/S can perform the task of
querying all the cards to determine their resource needs, picking a
valid configuration for all these cards, and telling the cards what their
actual resource settings are.
• If the BIOS
Installed O/S is set to Windows 95, Windows 98,
Windows 2000 or Running a PnP O/S, the BIOS will not perform
this task and will leave it to the O/S to do this. If the
Installed O/S
is set to
NOT PnP O/S, or Other, the BIOS will perform this task
and the system may not work properly.
Set 82350 Read/Write Performance Mode The 82350 card read
and write calls use one of two modes:
•
Polling. Bytes are transferred to/from the card, one at a time.
Polling mode is advantageous for transferring a small number of
bytes because the setup overhead is very low, but it does require
CPU involvement for each byte transferred.
•
Interrupt. An entire buffer is transferred to/from the card without
CPU involvement. Interrupt mode is advantageous for
transferring large buffers because the higher per byte transfer rate
more than compensates for the relatively long interrupt setup
overhead.