NI PXI-8423/2 Isolated 2-Port RS485 Interface for PXI

The NI PXI-8423/2 is a dual-port RS-485 interface module for PXI systems that delivers isolated serial communication in electrically demanding environments. It supports asynchronous data transfer up to 2 Mb/s across two independently configurable channels, each terminated with DB-9 male connectors. Optical isolation of 2000 V protects connected instrumentation from ground loops and transient noise common in industrial settings.

– Technical Specifications

Interfaces & Performance
• 2 RS-485/422 ports with DB-9 male connectors
• Maximum transfer rate: 2 Mb/s
• Baud rate support: 57 b/s to 2 Mb/s with 0.01% accuracy
• 64 byte FIFO buffer per port
• 2000 V optical isolation

Electrical & Physical
• Power consumption: 1,300 mA maximum at +5 VDC (800 mA typical)
• Dimensions: 10.67 × 14.22 cm (4.2 × 5.6 in.)

Environmental
• Operating temperature: −40°C to +85°C
• Humidity: 5% to 95% relative humidity, noncondensing (IEC-60068-2-56)
• Indoor use only

– Key Features

• Enhanced serial driver with advanced transceiver control modes optimized for RS-485 multipoint networks
• Plug-and-play installation with automatic hardware detection
• Interrupt sharing between ports reduces system overhead
• RS-485 termination resistor support for proper signal conditioning in long-line or heavily-loaded bus configurations
• Compatible with multiprocessor and hyperthreading architectures

– Typical Applications

Industrial automation, process control, SCADA systems, and distributed instrumentation requiring galvanic isolation and noise immunity in harsh electrical environments.

– Compatibility & Integration

Operating systems: Windows 2000, NT, XP, Me, 9x. Direct integration with standard serial port APIs supports development in Visual Basic, C++, Excel Visual Basic, NI-VISA, LabVIEW, LabWindows/CVI, Measurement Studio, and Lookout. Designed as a PXI module for seamless integration into existing chassis-based test systems.

Note: This product has been declared obsolete by National Instruments but may be available through third-party channels.