National Instrument GPIB-140 Overview
The National Instruments GPIB-140 / GPIB-140A Fiber Optic GPIB Extenders remove the restrictions on cable length and device loading imposed by the IEEE 488 standard while requiring virtually no desktop space. The IEEE 488 standard specifies that the total cable length for a GPIB system cannot exceed 20 m and the maximum number of devices is 15. A pair of NI GPIB-140A/2 bus extenders can extend the cable length to 2 km without compromising the integrity of the GPIB or requiring any application modifications. The GPIB-140A can use fiber-optic cable lengths up to 1 km.
These GPIB extenders use a buffered transfer technique to transfer data at the fastest rates in the industry, while keeping the cabling cost at a minimum. Each extender has an error-checking scheme to ensure an error-free link. The maximum data transfer rate over the extension with GPIB-140A extenders is more than 2.8 Mbyte/s using the HS488 protocol.