The NI GPIB-140A is a fiber optic GPIB extender that overcomes the distance and device loading constraints of IEEE 488 by extending GPIB bus communication up to 1 km—far beyond the standard 20 m cable limit. It translates GPIB signals into serial or parallel signals for transmission over fiber optic cable, then converts them back at the remote extender, all without requiring modification to existing GPIB control software.
Technical Specifications
Distance & Data Transfer
• Maximum extension distance: 1 km (fiber-optic cable)
• Data transfer rate (IEEE 488.1): Up to 1.1 MB/s
• Data transfer rate (HS488 protocol): More than 2.8 MB/s
• Error checking: Integrated for error-free transmission
Connectivity
• Primary interface: GPIB (IEEE 488.2) 24-pin connector
• Supported fiber cable types: T7 and T8 cables with ST connectors, 62.5/125 µm core/clad
• T7 cable: 850 nm operation, up to 1 km distance
• T8 cable: 1,300 nm operation, up to 2 km distance
• Additional T7 configurations: 10, 50, 100, 500, or 1,000 m cable lengths
Device Management & Modes
• Maximum extended GPIB devices: 26 (versus IEEE 488 standard limit of 15)
• Buffered transfer mode: Uses FIFO buffers for increased data rates; required for HS488
• Unbuffered transfer mode: Maintains IEEE 488 double-interlocked handshake across extension
• Parallel poll immediate mode: For distances up to 100 m
• Parallel poll latched mode: For longer distances; returns previous response, requires successive commands for current data
Physical
• Dimensions: 10.7 cm × 6.6 cm × 2.6 cm
• Weight: 180 g
– Key Features
• Software transparent—existing GPIB applications run unchanged
• Supports IEEE 488.1 and IEEE 488.2 protocols
• Series or star topology configuration for extended reach
• Integrated error checking ensures link integrity
– Compatibility & Integration
The GPIB-140A integrates with National Instruments GPIB controllers and complies with IEEE 488.1 and IEEE 488.2 standards, making it suitable for laboratory automation, instrumentation systems, and remote test equipment deployment where distance or device loading exceeds standard GPIB capabilities.
