The NI PCI-8431/4 is a 4-port serial interface card for PCI systems requiring RS485 and RS422 communication in industrial environments. It delivers high-speed data transfer via DMA to the PCI bus while maintaining minimal CPU overhead, making it ideal for applications demanding efficient multi-port serial connectivity without sacrificing system performance.
Technical Specifications
• Interface: PCI (universal 3.3 V and 5 V compatible)
• Ports: 4 independent serial channels
• Serial Standards: RS485, RS422
• Communication Modes: 4-wire full-duplex and 2-wire half-duplex transceiver operation
• Baud Rate Range: 2 b/s to 3 Mbps (2 Mbps max with 2-wire auto mode)
• Baud Rate Accuracy: 1% (non-standard rates), 0.01% (standard rates)
• FIFO Buffers: 128 B transmit and receive per port
• Data Transfer: DMA to PCI bus with interrupt/handshaking fallback
• Power Requirement: +5 VDC, 725 mA typical / 1.1 A maximum
• Connectors: 10-position modular jack (10P10C) with DB-9 cable adapters included
• Physical: 10.67 × 14.48 cm, approximately 102 g
– Key Features
• DMA-driven architecture reduces CPU utilization during sustained transfers
• Supports multiprocessor and hyper-threading systems
• Appears as standard COM ports for legacy serial application compatibility
• Memory-mapped I/O configuration prevents resource conflicts
• Configurable via MAX (Measurement & Automation Explorer) or NI-Serial API
– Typical Applications
• Industrial automation with distributed RS485/RS422 sensors and controllers
• Multi-channel data acquisition from legacy serial instruments
• System integration where high-speed, low-latency serial I/O is required
• Laboratory test systems requiring simultaneous RS485/RS422 communication
– Compatibility & Integration
• Windows 7/Vista/XP/2000/2003 Server, LabVIEW Real-Time
• Integrates with existing serial-based applications through standard COM port emulation
• Part Number: 778981-01
