GPIB: Advantages and Disadvantages

This page covers the advantages and disadvantages of GPIB (General Purpose Interface Bus). The GPIB IEEE-488 interface bus consists of 8-bit parallel lines. The GPIB connector has a total of 24 pins. It utilizes 16 signal lines, comprising 8 data lines (bi-directional), 3 handshake lines, and 5 for bus management. Additionally, there are 8 ground (GND) lines.

Figure 1: GPIB IEEE-488 connectors in plug and jack configurations.

The GPIB bus employs a 5-bit address, providing a total of 31 possible addresses for use by equipment on the GPIB interface. The IEEE standard permits approximately 15 devices to share a GPIB bus over a length of 20 meters.

Advantages of GPIB

The following are the advantages of using GPIB:

1. GPIB interface is simple.
2. GPIB interface port is widely available on all test and measurement equipment.
3. The GPIB cable uses very rugged and robust connectors.
4. Using the GPIB interface, a single controller can monitor and control multiple test and measurement equipment or instruments. This is illustrated in Figure 2, showing two different configurations: linear and star.

Figure 2: GPIB in linear and star connections.

Disadvantages of GPIB

The following are the disadvantages of using GPIB:

1. The GPIB connectors are bulky.
2. The interface provides low bandwidth data transfer.
3. The GPIB interface is used for low-speed data communication, unlike modern interfaces designed for high-speed communication.
4. Modern instruments have gradually discontinued its use. It is likely to become obsolete in a few years.