Differences in Measurement Between Sun and HP Systems

Differences in measurement between HP and SUN systems include the interface file, the select code, the bus lock and the timeout value.

Interface File

Because the Sun SPARCstation does not have an Agilent GPIB interface, a GPIB interface from National Instruments is used. This interface plugs into one SBus (or PCI depending on your machine's bus architecture) slot of the workstation and is named /dev/gpib0 to serve as a GPIB board. National Instruments has provided a library to control this interface either as a raw GPIB file or an addressed device. Refer to the NI488-M Software Manual for more information.

Select Code

IC-CAP treats the GPIB interface as a raw GPIB file. This requires a select code on HP to be replaced with a board number on Sun calculated from the minor number of the device file. National supports up to 2 interfaces per system. So the board number is either 1 (first board) or 2 (second board). When this number is larger than 2, it is an addressed device which is not suitable for IC-CAP operation. The installation script of the National interface creates /dev/gpib0 as a GPIB board file. The default GPIB address of the interface is 0 on Sun and 21 on HP. This should not cause any problems.

Bus Lock

Because of the limited capability of the National card, I-O Lock and I-O Unlock do not function. This means users must avoid concurrent accesses to the GPIB board used by IC-CAP.

Timeout Value

The available timeout values are: 10ms, 30ms, 100ms, 300ms, 1sec, 3sec, 10sec, 30sec, 100sec, 300sec, 1000sec, and None (0sec). Any value that falls between two discrete values becomes the larger one. A timeout value larger than 1000sec turns off the timeout mechanism.