Description
National Instruments GPIB-140 Product Description
Product Overview
NI GPIB-140 is a fiber-optic GPIB bus extender designed by National Instruments (NI) to extend IEEE-488/GPIB instrumentation networks over long distances while maintaining transparent communication between instruments and controllers.
The GPIB-140 converts standard electrical GPIB (IEEE 488) signals into optical signals, allowing two separated GPIB systems to communicate through fiber-optic cable. It is commonly used in automated test systems, EMC laboratories, semiconductor testing, aerospace test benches, and industrial measurement systems where long cable distances or electrical isolation are required.
Technical Specifications
| Parameter | Specification |
|---|---|
| Manufacturer | National Instruments (NI) |
| Model | GPIB-140 |
| Product Type | Fiber Optic GPIB Bus Extender |
| Interface Standard | IEEE 488 / GPIB |
| Communication Medium | Fiber optic |
| Extension Distance | Up to 2 km (system dependent) |
| Data Transfer Rate | > 1.1 MB/s (IEEE 488.1) |
| HS488 Transfer Rate | Up to 2.8 MB/s |
| Transfer Mode | Buffered / unbuffered |
| GPIB Device Capacity | Up to 26 devices |
| Optical Interface | Fiber optic transmitter/receiver |
| Application | Long-distance instrumentation communication |
| Isolation Type | Optical isolation |
The GPIB-140 family is designed to extend GPIB systems over fiber while preserving normal GPIB device operation.
Main Features
Long-Distance GPIB Extension
The primary function of the GPIB-140 is extending the reach of conventional IEEE-488 instrumentation networks beyond the normal copper GPIB cable limitation.
A typical configuration:
GPIB Controller → GPIB Cable → GPIB-140 → Fiber Cable → GPIB-140 → GPIB Instruments
This allows test equipment installed in different rooms, shielded chambers, or remote test areas to operate as if connected to the same GPIB bus.
Fiber-Optic Electrical Isolation
Because communication is transferred through optical fiber, the GPIB-140 provides electrical isolation between two GPIB environments.
Benefits include:
- Eliminating ground-loop problems
- Reducing electrical noise interference
- Supporting separated laboratory environments
- Improving safety when connecting equipment with different ground potentials
This makes it suitable for EMC testing and high-noise industrial measurement environments.
Transparent GPIB Communication
The GPIB-140 operates transparently, meaning connected instruments do not require special drivers or software modifications.
The controller communicates with instruments using normal GPIB commands while the extender handles signal conversion and transmission.
GPIB-140
High-Speed Data Transfer
The unit supports:
- IEEE 488.1 transfer rates up to approximately 1.1 MB/s
- HS488 high-speed mode up to approximately 2.8 MB/s
This allows use with high-performance automated test systems requiring faster instrument communication.
Expanded System Capacity
The GPIB-140 can increase the maximum number of connected GPIB devices in a system, supporting up to 26 GPIB devices in extended configurations.
Application Fields
Automated Test Equipment (ATE)
Used in:
- Production test systems
- Electronic device testing
- Instrument automation
- Measurement stations
The extender allows test instruments to be physically separated from the control computer while maintaining GPIB operation.
EMC / EMI Testing
Commonly used in electromagnetic compatibility laboratories where:
- Test equipment must be isolated from the DUT environment
- Shielded rooms require remote instrumentation placement
- Electrical noise reduction is required
Aerospace and Defense Testing
Suitable for test systems requiring:
- Long-distance instrument connections
- Reliable communication
- Electrical isolation
Semiconductor Testing
Used where precision measurement instruments need to be located away from test chambers or production areas.
Industrial Measurement Systems
Applicable to legacy industrial test setups using:
- Oscilloscopes
- Spectrum analyzers
- Power meters
- Network analyzers
- Digital multimeters
System Compatibility
The GPIB-140 works with standard GPIB equipment including:
- GPIB controllers
- IEEE-488 measurement instruments
- Automated test software platforms
Compatible software environments may include:
- NI LabVIEW
- LabWindows/CVI
- Standard IEEE-488 control software
No special instrument-side programming changes are normally required.
Related Products
- NI GPIB-140A — Fiber-optic GPIB extender supporting long-distance IEEE-488 communication.
- NI GPIB-140A/2 — Extended-distance version supporting longer fiber runs.
- NI GPIB-140B — Updated 1 km GPIB bus extender with buffered transfer technology.
- NI GPIB-120A — GPIB electrical isolation solution.
- NI PCI-GPIB / PCIe-GPIB — GPIB controller interfaces for PCs.
