The National Instruments GPIB-120A is a GPIB Expander and Isolator designed to enhance GPIB (IEEE 488.1) system capabilities by increasing the number of connectable devices from 15 to a maximum of 28. This device provides an electrically isolated interface, making it suitable for use in measurement and test systems. With transparent software, the GPIB-120A allows users to connect two GPIB systems without the need for rewiring application software, ensuring seamless integration. It effectively doubles the maximum allowable cable length to 20 meters and consists of two buses, Bus A and Bus B, which operate independently yet identically.

Each bus appears as an independent GPIB device, and the unit features seven front-panel LEDs that indicate the status of both the Active Controller and System Controller. The GPIB-120A includes 16 signal lines, which are categorized into five interface management lines, three handshake lines, and eight data lines, alongside eight shield drain or ground return lines. It is constructed with a durable case measuring 3.5 x 8.5 x 13.0 inches, made from UL94V-0 flame retardant polystyrene or Noryl material. The device operates within a temperature range of 0° to 45° C and sustains a non-condensing relative humidity of 5% to 95%. A typical power requirement is 27 VA, with a data transfer rate degradation of 250 ns per byte. The GPIB-120A is backed by a three-year warranty, and user manuals are available for download. For pricing, please consult a National Instruments sales representative.