{"id":34912,"date":"2026-08-08T16:50:13","date_gmt":"2026-08-08T08:50:13","guid":{"rendered":"https:\/\/pxisource.com\/?post_type=product&#038;p=34912"},"modified":"2026-08-31T16:08:57","modified_gmt":"2026-08-31T08:08:57","slug":"pxi-8431-2","status":"publish","type":"product","link":"https:\/\/pxisource.com\/ru\/product\/pxi-8431-2\/","title":{"rendered":"PXI-8431\/2"},"content":{"rendered":"<h3>PXI-8431\/2 2-Port RS-485\/RS-422 PXI Serial Interface Module<\/h3>\n<p>\u0417\u0435\u043c\u043b\u044f <strong>PXI-8431\/2<\/strong> is a two-port PXI serial instrument-control module designed for high-speed communication with RS-485 and RS-422 devices. It provides two independent male DB-9 connections in a single-slot PXI module.<\/p>\n<p>The module supports baud rates from 2 baud to 3 Mbps and can operate with two-wire or four-wire transceiver configurations. This allows the PXI-8431\/2 to support half-duplex RS-485 networks, full-duplex RS-422 links and compatible four-wire RS-485 devices.<\/p>\n<p>High-performance DMA transfers, 128-byte FIFOs, multithreaded software support and standard COM-port compatibility make the PXI-8431\/2 suitable for automated test systems, industrial communication, embedded-device validation and laboratory instrument control.<\/p>\n<h3>Key Features of the PXI-8431\/2<\/h3>\n<ul>\n<li>Two independent serial communication ports<\/li>\n<li>Supports RS-485 and RS-422 protocols<\/li>\n<li>Up to 3 Mbps maximum baud rate<\/li>\n<li>Supports programmable baud rates from 2 baud<\/li>\n<li>Selects between two-wire and four-wire transceiver modes<\/li>\n<li>Supports half-duplex and full-duplex communication<\/li>\n<li>Two-wire automatic transceiver control<\/li>\n<li>Up to 2 Mbps in two-wire automatic-control mode<\/li>\n<li>128-byte FIFO for each port<\/li>\n<li>Two male DB-9 front-panel connectors<\/li>\n<li>Nonisolated serial interface<\/li>\n<li>High-performance DMA transfers<\/li>\n<li>Multithreaded and multiprocessor support<\/li>\n<li>Appears as standard COM ports<\/li>\n<li>NI-Serial and NI-VISA compatibility<\/li>\n<li>LabVIEW Real-Time support<\/li>\n<li>Single-slot 3U PXI module<\/li>\n<\/ul>\n<h3>PXI-8431\/2 Technical Specifications<\/h3>\n<table>\n<tbody>\n<tr>\n<th>Product Model<\/th>\n<td>PXI-8431\/2<\/td>\n<\/tr>\n<tr>\n<th>Part Number<\/th>\n<td>778984-01<\/td>\n<\/tr>\n<tr>\n<th>Product Type<\/th>\n<td>PXI serial instrument-control module<\/td>\n<\/tr>\n<tr>\n<th>Supported Serial Protocols<\/th>\n<td>RS-485 and RS-422<\/td>\n<\/tr>\n<tr>\n<th>Number of Serial Ports<\/th>\n<td>2<\/td>\n<\/tr>\n<tr>\n<th>\u0418\u0437\u043e\u043b\u044f\u0446\u0438\u044f<\/th>\n<td>Nonisolated<\/td>\n<\/tr>\n<tr>\n<th>Transceiver Modes<\/th>\n<td>Two-wire and four-wire<\/td>\n<\/tr>\n<tr>\n<th>Duplex Modes<\/th>\n<td>Half-duplex and full-duplex<\/td>\n<\/tr>\n<tr>\n<th>Minimum Programmable Baud Rate<\/th>\n<td>2 baud<\/td>\n<\/tr>\n<tr>\n<th>Maximum Baud Rate<\/th>\n<td>3 Mbps<\/td>\n<\/tr>\n<tr>\n<th>Maximum Two-Wire Auto-Control Baud Rate<\/th>\n<td>2 Mbps<\/td>\n<\/tr>\n<tr>\n<th>Standard Baud Rates<\/th>\n<td>Supported<\/td>\n<\/tr>\n<tr>\n<th>Custom Baud Rates<\/th>\n<td>Supported from 2 baud to the applicable maximum<\/td>\n<\/tr>\n<tr>\n<th>Baud-Rate Accuracy<\/th>\n<td>UART operates within 1.3% of supported baud rates<\/td>\n<\/tr>\n<tr>\n<th>FIFO Size<\/th>\n<td>128 bytes per port<\/td>\n<\/tr>\n<tr>\n<th>Data Transfer Architecture<\/th>\n<td>High-performance DMA<\/td>\n<\/tr>\n<tr>\n<th>Operating-System Interface<\/th>\n<td>Standard COM ports<\/td>\n<\/tr>\n<tr>\n<th>Front-Panel Connectors<\/th>\n<td>2 \u00d7 male DB-9<\/td>\n<\/tr>\n<tr>\n<th>Bus Connection<\/th>\n<td>PXI Hybrid<\/td>\n<\/tr>\n<tr>\n<th>Typical Power Requirement<\/th>\n<td>500 mA from +5 VDC PXI supply<\/td>\n<\/tr>\n<tr>\n<th>Maximum Power Requirement<\/th>\n<td>750 mA from +5 VDC PXI supply<\/td>\n<\/tr>\n<tr>\n<th>Operating Temperature<\/th>\n<td>0\u00b0C to 55\u00b0C<\/td>\n<\/tr>\n<tr>\n<th>Dimensions<\/th>\n<td>100 \u00d7 160 mm<\/td>\n<\/tr>\n<tr>\n<th>Weight<\/th>\n<td>134 g<\/td>\n<\/tr>\n<tr>\n<th>Module Format<\/th>\n<td>3U, single-slot PXI module<\/td>\n<\/tr>\n<tr>\n<th>Primary Driver<\/th>\n<td>NI-Serial<\/td>\n<\/tr>\n<tr>\n<th>Instrument-Control Software<\/th>\n<td>NI-VISA<\/td>\n<\/tr>\n<tr>\n<th>Programming Support<\/th>\n<td>LabVIEW, LabWindows\/CVI and compatible text-based languages<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>PXI-8431\/2 Part Number and Connectivity<\/h3>\n<table>\n<tbody>\n<tr>\n<th>Item<\/th>\n<th>Part Number<\/th>\n<th>\u041e\u043f\u0438\u0441\u0430\u043d\u0438\u0435<\/th>\n<\/tr>\n<tr>\n<td>PXI-8431\/2<\/td>\n<td>778984-01<\/td>\n<td>Two-port, nonisolated RS-485\/RS-422 PXI serial interface<\/td>\n<\/tr>\n<tr>\n<td>Shielded DB-9 Serial Cable<\/td>\n<td>Application dependent<\/td>\n<td>Cable for connecting compatible RS-485 or RS-422 equipment<\/td>\n<\/tr>\n<tr>\n<td>DB-9 Breakout Adapter<\/td>\n<td>Application dependent<\/td>\n<td>Provides access to differential signal pairs for custom wiring<\/td>\n<\/tr>\n<tr>\n<td>RS-485 Termination Resistor<\/td>\n<td>Network dependent<\/td>\n<td>Termination selected according to cable impedance and network design<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>The PXI-8431\/2 provides two male DB-9 connectors directly on its front panel. RS-485 and RS-422 pinouts are not interchangeable with conventional RS-232 connections, even when both devices use DB-9 connectors.<\/p>\n<h3>Two Independent RS-485\/RS-422 Ports<\/h3>\n<p>The PXI-8431\/2 provides two independently configurable serial ports. Each port can communicate with a separate network or device and can use its own baud rate, data format and transceiver-control settings.<\/p>\n<p>One port can operate in two-wire RS-485 mode while the second operates in four-wire RS-422 or RS-485 mode. This allows the module to support equipment with different communication requirements simultaneously.<\/p>\n<h3>RS-485 Communication<\/h3>\n<p>RS-485 uses differential signaling to improve noise immunity and support longer cable distances than typical single-ended RS-232 connections. It is widely used by industrial controllers, automation equipment, sensors, drives and embedded systems.<\/p>\n<p>Two-wire RS-485 uses one differential pair for both transmitting and receiving. Only one transmitter should normally drive the bus at a time, making transceiver-direction control an important part of reliable communication.<\/p>\n<h3>RS-422 Communication<\/h3>\n<p>RS-422 also uses differential signaling but is commonly configured with separate transmit and receive pairs. This four-wire arrangement supports simultaneous full-duplex communication.<\/p>\n<p>RS-422 is frequently used for point-to-point or limited multidrop communication where long cable distances, high speed and improved noise immunity are required.<\/p>\n<h3>Two-Wire Half-Duplex Mode<\/h3>\n<p>In two-wire mode, transmitting and receiving share one differential pair. The PXI-8431\/2 enables its transmitter when sending data and releases the bus so other devices can respond.<\/p>\n<p>Half-duplex systems require a communication protocol that prevents multiple devices from transmitting at the same time. A master-and-slave or request-and-response structure is commonly used.<\/p>\n<h3>Automatic Transceiver Control<\/h3>\n<p>The PXI-8431\/2 supports automatic transceiver-direction control for two-wire RS-485 networks. The hardware manages transmitter enable and disable timing without requiring the application to toggle a separate control signal for every message.<\/p>\n<p>The maximum baud rate in two-wire automatic-control mode is 2 Mbps. Other supported configurations can operate at rates up to the module\u2019s 3 Mbps maximum.<\/p>\n<h3>Four-Wire Full-Duplex Mode<\/h3>\n<p>Four-wire mode uses separate differential pairs for transmitting and receiving. This allows both devices to transmit simultaneously and eliminates the need to reverse a shared data pair.<\/p>\n<p>The connected device\u2019s transmit pair must connect to the PXI-8431\/2 receive pair, and the device\u2019s receive pair must connect to the module\u2019s transmit pair. Incorrect pair direction is a common cause of communication failure.<\/p>\n<h3>3 Mbps Maximum Baud Rate<\/h3>\n<p>The PXI-8431\/2 supports maximum serial communication speeds up to 3 Mbps. This enables faster data transfer than conventional serial interfaces limited to lower standard baud rates.<\/p>\n<p>Actual reliable speed depends on cable length, cable impedance, network topology, termination, device capability and electrical noise. Longer networks may require lower baud rates.<\/p>\n<h3>Flexible Programmable Baud Rates<\/h3>\n<p>The module supports standard baud rates and programmable rates beginning at 2 baud. Its UART can generate supported baud rates within approximately 1.3% of the requested value.<\/p>\n<p>This capability is useful for devices that communicate with proprietary or uncommon baud rates. Both ends of the connection must tolerate the resulting baud-rate accuracy.<\/p>\n<h3>128-Byte FIFO Architecture<\/h3>\n<p>Each port includes a 128-byte FIFO for transmitted and received data. The FIFO reduces the number of processor service operations and provides buffering during periods of high system activity.<\/p>\n<p>Application software must still process incoming data at an adequate rate. Continuous traffic can eventually overflow the receive buffer if the application stops reading the port.<\/p>\n<h3>High-Performance DMA Transfers<\/h3>\n<p>The PXI-8431\/2 supports DMA transfers between the serial interface and system memory. DMA reduces processor overhead and helps sustain communication while the controller performs other measurement and automation tasks.<\/p>\n<p>This architecture is useful in systems that log continuous serial data while simultaneously controlling PXI instruments or processing measurement results.<\/p>\n<h3>Standard COM-Port Compatibility<\/h3>\n<p>After installation of the NI-Serial driver, each PXI-8431\/2 channel appears as a standard COM port in supported operating systems.<\/p>\n<p>Existing serial applications can communicate with the module using conventional COM-port APIs. NI-VISA applications can also assign descriptive resource aliases to avoid depending on changeable COM numbers.<\/p>\n<h3>Nonisolated Interface Design<\/h3>\n<p>The PXI-8431\/2 does not provide electrical isolation between its ports and the PXI system. It is appropriate where connected devices share a compatible ground reference and isolation is not required.<\/p>\n<p>For equipment exposed to ground-potential differences, electrical transients or substantial common-mode noise, consider the isolated PXI-8433\/2.<\/p>\n<h3>Differential Cable Wiring<\/h3>\n<p>Use twisted-pair cable for RS-485 and RS-422 differential signals. Each positive and negative signal pair should remain twisted throughout the cable to preserve noise rejection.<\/p>\n<p>Shielding can improve performance in electrically noisy environments. Connect the shield according to the grounding requirements of the complete installation to avoid creating unwanted ground-current paths.<\/p>\n<h3>Network Termination<\/h3>\n<p>High-speed or long-distance RS-485 networks typically require termination at the physical ends of the main bus. The termination resistance should match the characteristic impedance of the cable.<\/p>\n<p>Excessive termination can overload the transmitters, while missing or incorrectly placed termination can produce reflections and data errors. Avoid installing termination at every intermediate node.<\/p>\n<h3>Biasing and Idle-State Control<\/h3>\n<p>A two-wire RS-485 bus can enter an undefined state when no transmitter is active. Bias resistors may be used to maintain a known logic state during idle periods.<\/p>\n<p>Before adding external biasing, check whether another network device already provides it. Multiple strong bias networks can unnecessarily load the bus.<\/p>\n<h3>Multidrop RS-485 Networks<\/h3>\n<p>RS-485 allows multiple devices to share a differential bus. The network should normally use a linear daisy-chain layout with short device stubs rather than a star configuration.<\/p>\n<p>Every device must use a unique protocol address when required by the application. The serial electrical standard defines the physical layer but does not assign device addresses or message formats.<\/p>\n<h3>Typical PXI-8431\/2 Applications<\/h3>\n<ul>\n<li>Industrial controller communication<\/li>\n<li>RS-485 multidrop networks<\/li>\n<li>RS-422 point-to-point links<\/li>\n<li>Automated instrument control<\/li>\n<li>Embedded system validation<\/li>\n<li>Motor drive and motion-system communication<\/li>\n<li>Environmental chamber control<\/li>\n<li>Remote sensor communication<\/li>\n<li>Production functional testing<\/li>\n<li>Serial data acquisition and logging<\/li>\n<li>Hardware-in-the-loop testing<\/li>\n<li>LabVIEW Real-Time communication<\/li>\n<\/ul>\n<h3>Industrial Automation Systems<\/h3>\n<p>The PXI-8431\/2 can communicate with industrial controllers, motor drives, sensors and other equipment using RS-485 or RS-422 interfaces.<\/p>\n<p>Its two independent ports allow one PXI system to operate two separate networks or connect simultaneously to a device under test and supporting automation equipment.<\/p>\n<h3>Automated Production Testing<\/h3>\n<p>In a production test system, the module can communicate with embedded controllers and devices while other PXI instruments perform electrical or functional measurements.<\/p>\n<p>DMA transfers and independent FIFOs help maintain serial traffic while the controller handles test execution, measurement processing and report generation.<\/p>\n<h3>Embedded Device Validation<\/h3>\n<p>The PXI-8431\/2 can send commands, receive diagnostic messages and validate serial protocols implemented by embedded devices. Custom baud-rate support accommodates products that do not use conventional communication rates.<\/p>\n<p>Test software can intentionally vary baud rate, data format and timing to confirm that the device handles valid and invalid serial traffic correctly.<\/p>\n<h3>LabVIEW Real-Time Integration<\/h3>\n<p>The module can be used with compatible LabVIEW Real-Time PXI controllers. A real-time application can coordinate serial communication with data acquisition, stimulus generation and control-system simulation.<\/p>\n<p>The response timing of an external serial device is not inherently deterministic. Test sequences should include suitable timeouts and message-completion checks.<\/p>\n<h3>NI-Serial Driver Support<\/h3>\n<p>The NI-Serial driver provides hardware support, COM-port integration and configuration utilities for the PXI-8431\/2. Installed interfaces can be inspected and configured through NI Measurement &amp; Automation Explorer.<\/p>\n<p>Verify compatibility between the NI-Serial version, controller operating system and application-development software before adding the module to an existing test system.<\/p>\n<h3>NI-VISA Integration<\/h3>\n<p>NI-VISA offers a common programming interface for serial and other instrument-control connections. Applications can use VISA functions to configure baud rate, data format, timeouts and termination behavior.<\/p>\n<p>VISA aliases allow descriptive resource names such as DRIVE_CONTROLLER or DUT_SERIAL to replace system-dependent COM-port numbers.<\/p>\n<h3>PXI Chassis Integration<\/h3>\n<p>The PXI-8431\/2 occupies one slot in a compatible 3U PXI or PXI hybrid-slot chassis. It can operate alongside data acquisition modules, controllers, digitizers and other PXI instruments.<\/p>\n<p>Before installation, verify chassis compatibility, available slot space, controller support and NI-Serial driver compatibility.<\/p>\n<h3>PXI-8431\/2 Troubleshooting<\/h3>\n<h4>The PXI-8431\/2 Is Not Detected in NI MAX<\/h4>\n<p>Confirm that the module is fully installed in a compatible PXI slot. Check chassis power, controller communication and NI-Serial installation, then restart NI Measurement &amp; Automation Explorer.<\/p>\n<h4>The Serial Ports Do Not Appear as COM Ports<\/h4>\n<p>Verify that the installed NI-Serial driver supports the operating system and module. Rescan the hardware in NI MAX or Device Manager and restart the system if necessary.<\/p>\n<h4>No Data Is Received<\/h4>\n<p>Check the baud rate, parity, data bits and stop bits. Verify the DB-9 pinout, differential-pair polarity and whether the application requires two-wire or four-wire operation.<\/p>\n<h4>Communication Works Only in One Direction<\/h4>\n<p>In four-wire mode, confirm that each transmitter connects to the opposite device\u2019s receiver. In two-wire mode, verify transceiver-control settings and make sure the other device releases the bus.<\/p>\n<h4>Data Is Corrupted at Higher Baud Rates<\/h4>\n<p>Shorten the cable, verify the twisted-pair wiring and install appropriate termination at the physical ends of the network. Reduce the baud rate if the cable or connected equipment cannot support 3 Mbps.<\/p>\n<h4>Some Devices on a Multidrop Network Do Not Respond<\/h4>\n<p>Check device addresses, bus topology, termination and biasing. Avoid long stubs and confirm that only one device transmits at a time.<\/p>\n<h4>The Two-Wire Bus Remains Busy<\/h4>\n<p>Verify automatic transceiver-control configuration and confirm that no other node holds its transmitter enabled continuously. Review the protocol timing between request and response messages.<\/p>\n<h4>Communication Fails Above 2 Mbps in Auto Mode<\/h4>\n<p>The two-wire automatic-control mode has a maximum baud rate of 2 Mbps. Use a different transceiver-control mode or reduce the configured baud rate.<\/p>\n<h4>Communication Is Affected by Ground-Potential Differences<\/h4>\n<p>The PXI-8431\/2 is nonisolated. Correct the grounding problem or select the isolated PXI-8433\/2 for systems requiring electrical isolation.<\/p>\n<h3>PXI-8431\/2 Comparison with Similar Serial Modules<\/h3>\n<table>\n<tbody>\n<tr>\n<th>\u041c\u043e\u0434\u0435\u043b\u044c<\/th>\n<th>\u041a\u043e\u043d\u0444\u0438\u0433\u0443\u0440\u0430\u0446\u0438\u044f<\/th>\n<th>Best Suited For<\/th>\n<\/tr>\n<tr>\n<td>PXI-8430\/2<\/td>\n<td>2-port RS-232, nonisolated, 1 Mbps<\/td>\n<td>Point-to-point RS-232 instrument control<\/td>\n<\/tr>\n<tr>\n<td>PXI-8431\/2<\/td>\n<td>2-port RS-485\/RS-422, nonisolated, 3 Mbps<\/td>\n<td>Differential and multidrop serial communication<\/td>\n<\/tr>\n<tr>\n<td>PXI-8431\/4<\/td>\n<td>4-port RS-485\/RS-422, nonisolated, 3 Mbps<\/td>\n<td>Additional differential serial channels<\/td>\n<\/tr>\n<tr>\n<td>PXI-8431\/8<\/td>\n<td>8-port RS-485\/RS-422, nonisolated, 3 Mbps<\/td>\n<td>High-channel-count industrial communication<\/td>\n<\/tr>\n<tr>\n<td>PXI-8433\/2<\/td>\n<td>2-port RS-485\/RS-422, isolated, 3 Mbps<\/td>\n<td>Differential communication requiring isolation<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>PXI-8431\/2 vs PXI-8430\/2<\/h3>\n<p>\u0417\u0435\u043c\u043b\u044f <a href=\"https:\/\/pxisource.com\/ru\/product\/pxi-8430-2\/\">PXI-8430\/2<\/a> provides two RS-232 ports with maximum baud rates of 1 Mbps. The PXI-8431\/2 provides two RS-485\/RS-422 ports with speeds up to 3 Mbps.<\/p>\n<p>Choose the PXI-8430\/2 for conventional point-to-point RS-232 instruments. Choose the PXI-8431\/2 for differential signaling, longer cable distances or multidrop RS-485 networks.<\/p>\n<h3>PXI-8431\/2 vs PXI-8433\/2<\/h3>\n<p>The PXI-8431\/2 and <a href=\"https:\/\/pxisource.com\/ru\/product\/pxi-8433-2\/\">PXI-8433\/2<\/a> both provide two RS-485\/RS-422 ports. The primary difference is that the PXI-8431\/2 is nonisolated, while the PXI-8433\/2 includes electrical isolation.<\/p>\n<p>Select the PXI-8431\/2 for systems with compatible grounding. Select the PXI-8433\/2 when connected equipment may have ground-potential differences or requires additional electrical protection.<\/p>\n<h3>PXI-8431\/2 vs PXI-8431\/4<\/h3>\n<p>The PXI-8431\/2 provides two direct DB-9 serial ports. The <a href=\"https:\/\/pxisource.com\/ru\/product\/pxi-8431-4\/\">PXI-8431\/4<\/a> provides four RS-485\/RS-422 channels through 10-position modular connectors and adapter cables.<\/p>\n<p>Choose the PXI-8431\/2 for direct DB-9 connectivity and two networks. Choose the PXI-8431\/4 when additional port density is required.<\/p>\n<h3>Recommended Related Products<\/h3>\n<ul>\n<li><a href=\"https:\/\/pxisource.com\/ru\/product\/pxi-8430-2\/\">PXI-8430\/2 2-Port RS-232 Serial Module<\/a><\/li>\n<li><a href=\"https:\/\/pxisource.com\/ru\/product\/pxi-8431-4\/\">PXI-8431\/4 4-Port RS-485\/RS-422 Module<\/a><\/li>\n<li><a href=\"https:\/\/pxisource.com\/ru\/product\/pxi-8431-8\/\">PXI-8431\/8 8-Port RS-485\/RS-422 Module<\/a><\/li>\n<li><a href=\"https:\/\/pxisource.com\/ru\/product\/pxi-8433-2\/\">PXI-8433\/2 2-Port Isolated RS-485\/RS-422 Module<\/a><\/li>\n<li><a href=\"https:\/\/pxisource.com\/ru\/product\/pxi-8433-4\/\">PXI-8433\/4 4-Port Isolated RS-485\/RS-422 Module<\/a><\/li>\n<li><a href=\"https:\/\/pxisource.com\/ru\/product-category\/%d0%bd%d0%b8\/pxi-%d1%81%d0%b8%d1%81%d1%82%d0%b5%d0%bc%d1%81\/%d0%bc%d0%be%d0%b4%d1%83%d0%bb%d0%b8-pxi\/\">View More NI PXI and PXI Express Modules<\/a><\/li>\n<\/ul>\n<h3>Selecting the Right PXI Serial Interface<\/h3>\n<p>Choose the PXI-8431\/2 when the application requires two nonisolated RS-485 or RS-422 ports, direct DB-9 connections, selectable two-wire or four-wire operation and communication speeds up to 3 Mbps.<\/p>\n<p>Select a higher-port-count PXI-8431 model when more networks are required. Choose the PXI-8433\/2 when isolation is necessary or the PXI-8430\/2 when the connected equipment uses RS-232.<\/p>\n<h3>Why Choose the PXI-8431\/2?<\/h3>\n<ul>\n<li>Provides two independent RS-485\/RS-422 ports<\/li>\n<li>Supports baud rates through 3 Mbps<\/li>\n<li>Supports custom baud rates from 2 baud<\/li>\n<li>Provides two-wire and four-wire transceiver modes<\/li>\n<li>Supports half-duplex and full-duplex communication<\/li>\n<li>Includes automatic two-wire transceiver control<\/li>\n<li>Provides direct DB-9 front-panel connections<\/li>\n<li>Includes 128-byte FIFOs<\/li>\n<li>Uses DMA to reduce processor overhead<\/li>\n<li>Integrates with NI-Serial and NI-VISA<\/li>\n<\/ul>\n<h3>Frequently Asked Questions<\/h3>\n<h4>What Is the PXI-8431\/2?<\/h4>\n<p>The PXI-8431\/2 is a two-port, nonisolated RS-485\/RS-422 serial interface module for PXI test and control systems.<\/p>\n<h4>What Is the PXI-8431\/2 Part Number?<\/h4>\n<p>The standard NI part number for the PXI-8431\/2 is <strong>778984-01<\/strong>.<\/p>\n<h4>How Many Serial Ports Does It Provide?<\/h4>\n<p>The module provides two independent RS-485\/RS-422 ports.<\/p>\n<h4>What Is the Maximum Baud Rate?<\/h4>\n<p>The maximum supported baud rate is 3 Mbps. Two-wire automatic transceiver-control mode is limited to 2 Mbps.<\/p>\n<h4>Does It Support Two-Wire RS-485?<\/h4>\n<p>Yes. The module supports two-wire half-duplex RS-485 with automatic transceiver-direction control.<\/p>\n<h4>Does It Support Four-Wire Communication?<\/h4>\n<p>Yes. It supports four-wire full-duplex RS-422 and compatible RS-485 configurations.<\/p>\n<h4>What Connectors Does It Use?<\/h4>\n<p>The PXI-8431\/2 provides two male DB-9 connectors directly on its front panel.<\/p>\n<h4>Is the PXI-8431\/2 Isolated?<\/h4>\n<p>No. It is a nonisolated interface. Choose the PXI-8433\/2 when isolated RS-485 or RS-422 ports are required.<\/p>\n<h4>What Is the FIFO Size?<\/h4>\n<p>Each serial port includes a 128-byte FIFO.<\/p>\n<h4>Does It Appear as Standard COM Ports?<\/h4>\n<p>Yes. After installation of the NI-Serial driver, the two channels appear as standard COM ports in supported operating systems.<\/p>\n<h4>Can the PXI-8431\/2 Communicate with RS-232 Devices?<\/h4>\n<p>No. RS-232 uses different electrical signaling. Use a PXI-8430 or PXI-8432 model for RS-232 communication.<\/p>\n<h4>Which Software Controls the PXI-8431\/2?<\/h4>\n<p>The module uses the NI-Serial driver and can be programmed through NI-VISA, LabVIEW, LabWindows\/CVI and supported text-based languages.<\/p>\n<h4>Is the PXI-8431\/2 Still Available from NI?<\/h4>\n<p>NI lists part number 778984-01 as no longer available for direct purchase and under limited support. Used, refurbished or new-surplus units may remain available from specialized PXI suppliers.<\/p>\n<h3>Request a Quote for the PXI-8431\/2<\/h3>\n<p>Contact us for current availability, condition, lead time and project pricing for the <strong>PXI-8431\/2 2-Port RS-485\/RS-422 PXI Serial Interface Module<\/strong>. We can also help identify compatible DB-9 cables, isolated serial modules, PXI chassis and higher-channel-count interfaces for your system.<\/p>","protected":false},"excerpt":{"rendered":"<p>PXI-8431\/2 2-Port RS-485\/RS-422 PXI Serial Interface Module The PXI-8431\/2 is a two-port PXI serial instrument-control module designed for high-speed communication<\/p>","protected":false},"featured_media":34825,"template":"","meta":{"_acf_changed":false},"product_brand":[18],"product_cat":[667],"product_tag":[],"class_list":["post-34912","product","type-product","status-publish","has-post-thumbnail","product_brand-national-instruments","product_cat-pxi-modules","first","instock","shipping-taxable","product-type-simple"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v25.0 (Yoast SEO v28.4) - https:\/\/yoast.com\/product\/yoast-seo-premium-wordpress\/ -->\n<title>NI PXI-8431\/2 PXI Serial Interface Module 778984-01, In Stock | Project Pricing<\/title>\n<meta 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