Test And Troubleshooting - National Instruments Corporation GPIB-1014P User Manual

Theory of Operation Section Six

Test and Troubleshooting

The GPIB-1014P is designed to aid acceptance testing and troubleshooting of either hardware
failures or software bugs. The hardware provides several features that enable stand-alone testing.
The NDAC* and DIO1* bits can be used to determine if the output signals of the TLC, the
75160A, and the 75162A are functioning properly. Since most failures (including problems with
short or open circuits on the PWB) prevent the TLC from working at all, this test gives limited
assurance that the TLC and its associated circuitry are working and that the output signals can be
manipulated properly.
NDAC* is the GPIB Not Data Accepted signal. By programming the TLC to Listen or not Listen
via the ADMR, NDAC* can be asserted or not asserted, respectively.
DIO1* is the GPIB Data Input/Output bit 1 (LSB). By programming the TLC as active GPIB
Controller and sending command bytes using the CO bit, the CDOR, DIO1* can be asserted and
unasserted for testing.
GPIB-1014P User Manual 6-6 © National Instruments Corporation