I. Basic Information

Model: PCI‑8433/2

Part Number: 779144‑01

Bus: 32-bit PCI / PCI‑X (33 MHz) (Does not support PCIe)

Ports: 2 × Isolated RS‑485/RS‑422, DB‑9 connector

Isolation: Port-to-port, Port-to-PC high-voltage isolation (60 VDC continuous, 2000 Vrms/5 s withstand voltage)

Protocol: RS‑485 (2/4-wire), RS‑422, Half-duplex / Full-duplex optional

Status: EOL; Replacement: PCIe‑8433/2 (PCIe isolated RS‑485/422)

II. Core Specifications

Baud Rate: Up to 3 Mbps (3,000 kbaud), 57 - 3,000,000 programmable, error < 1%

FIFO: 128 bytes TX/RX FIFO per port, reducing CPU usage

Transmission Mode: DMA transmission, supports multi-threading / multi-core CPU

Differential Anti-interference: Differential RS-485/422, stable over long distances

Connector: 2 × DB-9 female connectors with shielding

Board Type: Half-length PCI card, compatible with industrial computers / old PCs

Power Supply: 5V power supply via PCI slot, no external power supply required

III. Comparison of PCI-843x Series (Quick Selection)

PCI-8430/2: RS-232, 2 ports, non-isolated (short distance, ordinary environment)

PCI-8431/2: RS-485/422, 2 ports, non-isolated (long distance, weak interference)

PCI-8432/2: RS-232, 2 ports, high-voltage isolation (strong interference, RS-232 device)

PCI-8433/2: RS-485/422, 2 ports, high-voltage isolation (strong interference, long distance, bus type)

IV. System Compatibility (Drivers + OS)

Driver: NI-Serial (with NI-VISA)

Supported Systems:

✅ Windows 2000/XP/Vista/7 (32/64) ✅ LabVIEW Real‑Time

❌ Windows 10/11: Compatible mode is available, but not officially supported

Software: LabVIEW, NI-DAQ, VISA, CVI, Modbus, etc.

Identification: The system is enumerated as a standard COM port (such as COM3, COM4)

VII. Installation and Use (Minimal)

Power off → Insert PCI/PCI-X slot (strictly prohibit PCIe)

Power on → Install NI-Serial driver → Restart

Device Manager → Ports → The NI PCI-8433/2 COMx appears

Connection: DB-9 to RS-485 (2-wire / 4-wire) or RS-422 device

Software directly reads and writes, same as ordinary COM port

VI. Typical Applications (Strong Interference + Long Distance)

Industrial bus: Modbus-RTU, PROFIBUS, etc. RS-485 bus

Long-distance communication: RS-485 stable within 1.2 km (115.2 kbps)

Strong electromagnetic environment: near frequency converters, motors, substations, welding equipment

Multi-node network: 1 host with 32 slaves (RS-485 bus)

VIII. Common Issues

❌ PCIe slot cannot be used: Must use old-fashioned PCI/PCI-X

⚠️ Isolation safety: The isolation terminal must not be connected to the ground to avoid ground circulation

⚠️ Terminal resistance: Connect 120 Ω resistor at both ends of the RS-485 bus to reduce reflection