Tektronix Keithley KPCI-488LPA, Quick Start Manual, Page: 5 / 14

KPCI-488LPA GPIB Controller Interface Card Quick Start Guide
KPCI-488LPA-903-01 Rev. B / January 2020
5
Cabling
For optimal GPIB throughput, adhere to the following cabling guidelines:

The longest distance between two devices cannot exceed 4 m.

The average GPIB bus distance between all devices should be less than 2 m.

The total GPIB bus distance should be less than 20 m.

The total number of connected devices must be less than 15 (including your computer) with at least
two-thirds of all devices powered on.
You can connect devices in a linear configuration, star configuration, or a combination of the two configurations.
See the next figures.
Figure 3: Linear connection configuration
To lower the total current load of the configuration, limit the number of cable connections on each
individual instrument to three or less. For example, to lower the required current load when using the
configuration shown in the next figure, move one of the cable connections from Instrument A to a
different instrument. This makes the configuration a combination of linear and star configurations.