RFGPIB vs. Serial Interfaces: A Comparison
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This article outlines the fundamental differences between GPIB (General Purpose Interface Bus) and serial interfaces (RS232, RS485). It also touches upon other instrument interfaces and related terminology.
GPIB Interface
GPIB, short for General Purpose Interface Bus, is also known as IEEE-488. It’s favored for its rapid data transfer capabilities when coupled with appropriate application software.
A single GPIB can accommodate up to 14 devices. However, it has limitations:
- The distance between the computer and the microlink is limited to approximately 2 meters.
- A computer adaptor is generally needed for interfacing.
Serial Interfaces (RS232, RS485)
Popular serial interfaces include RS232 and RS485. RS232 is primarily used for point-to-point connections, while RS485 supports one-to-many connections (also known as multi-drop).
In the past, computers were commonly equipped with RS232 serial ports (9-pin). Today, these are less common, often necessitating a USB to RS232 adapter. An adapter is typically also required for RS485.
For more detailed technical specifications, refer to a comparison of RS232 and RS485.
GPIB vs. Serial: Key Specifications
| Specification | GPIB Interface | Serial Interface |
|---|---|---|
| Maximum Distance | 2 meters | 50 meters (RS232), 1000 meters (RS485) |
| Maximum Speed | 1 MHz | 700 samples/second (RS232/RS485) |
| Number of Devices | 14 per cable | 1 per cable (RS232), 31 per cable (RS485) |
| Computer Adaptor | Card Needed | Not needed for RS232, Needed for RS485 |
| Microlink Hardware | 3000 series | 3000 series, 826 units (RS232/RS485) |
