The National Instruments PXI-8421/4 is a four-port, non-isolated RS-485/RS-422 serial interface for PXI systems, supporting rates up to 460.8 kbit/s.
Request current pricing and lead time for this model. Our team will confirm the exact equipment configuration and condition.
Key product information and technical features.
The PXI-8421/4 adds serial communication to a PXI system. NI documents support for two-wire and four-wire devices through four hardware transceiver control modes.
The four-port design uses 10-position modular jacks. Appropriate adapter cables convert these connections to DB-9 or DB-25 connectors; confirm the required pinout before connecting equipment.
Verified product specifications.
| Port count | 4 ports |
|---|---|
| Serial standards | RS-485 / RS-422 |
| Maximum serial rate | 460.8 kbit/s |
| Connector type | 10P10C |
| Isolation | No |
| FIFO size | 64 bytes |
| Typical current at +5 VDC | 350 mA |
| Maximum current at +5 VDC | 750 mA |
Confirm condition, included accessories and revision before ordering.
Confirmed per unit.
Device / accessories confirmed in quote.
Exact revision confirmed when relevant.
Review system components and compatibility requirements.
Manufacturer
Hardware platform
Four-port serial interface
NI-Serial 17.0 for LabVIEW Real-Time removed support for PXI-8421 interfaces.
Manuals, software and technical resources for this model.
Review shipping, warranty and return terms before ordering.
Choose pricing, rental or repair for this exact model.
Product-specific answers based on available technical information.
No. NI lists this model for RS-485 and RS-422, not RS-232.
No. The four-port board uses 10-position modular jacks. NI documents adapter cables for DB-9 or DB-25 connections.
No. That release explicitly removed PXI-8421 support. Check the intended legacy driver, operating system and controller combination before integration.