C Series Communication Module

NI C Series Communication Modules

C Series Communication Interface Types

Representative NI C Series Communication Module Families

Confirm the complete part number before ordering. Protocol support, port quantity, connector type, electrical isolation and supported CompactDAQ or CompactRIO platforms can differ within the same module family.

How to Select a C Series Communication Module

1. Identify the Protocol and Physical Layer

Determine whether the connected equipment uses CAN, CAN FD, LIN, FlexRay, Ethernet, RS-232, RS-422 or RS-485. Protocol names alone are not enough: confirm the electrical signaling standard, connector, cable type, network topology and any required termination.

For example, a device described as “serial” may require RS-232 point-to-point communication, RS-485 multidrop wiring or RS-422 differential signaling. These interfaces are not electrically interchangeable.

2. Confirm Channel Count and Network Topology

Count the number of independent buses or serial ports required. One physical CAN network normally uses one interface channel, while separate vehicle networks, isolated subsystems or simultaneous simulation and logging may require multiple channels.

For RS-485 systems, also determine whether the application uses two-wire or four-wire wiring, half-duplex or full-duplex communication, and multiple nodes on one bus.

3. Verify Data Rate and Bus Loading

Confirm the required baud rate, message frequency, frame type and expected bus loading. A module must support not only the nominal network rate but also the complete application workload, including monitoring, transmission, timestamping and data logging.

CAN FD applications should verify both arbitration-phase and data-phase communication requirements. High traffic levels may also increase host processing and file-storage requirements during long-duration logging.

4. Evaluate Isolation and Grounding

Isolation is important when equipment operates at different ground potentials, when communication wiring extends across machinery or vehicles, or when electrical noise is expected. Isolated interfaces can help reduce ground-loop risk and protect the measurement or control system from common-mode disturbances.

Isolation does not remove the need for correct cable shielding, grounding and termination. Review the complete wiring arrangement before connecting a module to powered equipment.

5. Plan Termination and Cabling

CAN networks normally require termination at the two physical ends of the bus. Incorrect termination, excessive stub length, unsuitable cable or poor shield connection can cause communication errors even when the selected module supports the correct protocol.

Serial and Ethernet systems also require appropriate cable type, pinout, shielding and connector conversion. Confirm whether the required terminal block, breakout cable or adapter is included in the planned system.

6. Review Timing and Timestamping Requirements

Logging applications often require accurate timestamps so bus traffic can be correlated with analog measurements, digital I/O, GPS data or control events. Determine whether the test needs approximate software timestamps, hardware timestamps, synchronized acquisition or deterministic real-time response.

For mixed I/O systems, plan synchronization at the system level. A communication interface installed in the same chassis as an analog module does not automatically guarantee that all data shares the same timing reference.

7. Confirm Software and Database Compatibility

Automotive communication modules commonly use NI-XNET software for supported CAN, LIN and FlexRay applications. Serial interfaces typically use the applicable NI serial or VISA software stack. Verify driver support for the exact module, operating system and controller before purchase.

Vehicle-network applications may also require DBC, FIBEX, LDF or other signal-description files. These databases define message IDs, signal scaling, byte order and network schedules; the hardware interface alone does not provide this application information.

CAN, CAN FD, LIN and FlexRay Considerations

CAN and CAN FD

CAN is widely used for robust distributed communication in vehicles, battery systems, industrial equipment and machinery. CAN FD extends the format to support larger payloads and, in supported networks, a faster data phase. Confirm whether the system uses classic CAN only or requires CAN FD capability.

Review nominal bit rate, CAN FD data rate, network termination, cable length, node count and the need to transmit, receive, log or simulate messages. A passive monitoring application can have different requirements from an ECU simulation or hardware-in-the-loop system.

LIN

LIN is a lower-cost single-wire automotive network commonly used for body electronics and local subsystems. Selection should account for master or slave behavior, schedule timing, signal database availability and the intended monitoring or simulation role.

FlexRay

FlexRay is designed for deterministic automotive communication and can be used where timing behavior is critical. Confirm the network configuration, channel arrangement, synchronization requirements and the software environment used to configure and interpret the traffic.

Serial and Ethernet Communication Considerations

RS-232, RS-422 and RS-485

RS-232 is generally used for short-distance point-to-point communication. RS-422 and RS-485 use differential signaling and are commonly selected for longer cable runs or electrically noisy industrial environments. RS-485 also supports multidrop network arrangements when wired and terminated correctly.

Confirm connector pinout, handshake signals, duplex mode, voltage levels, cable length and whether galvanic isolation is required. Legacy serial devices often use manufacturer-specific command sets that must be supported by the control software.

Ethernet

Ethernet connectivity can support network-connected instruments, embedded equipment and distributed test architectures. Selection should consider the intended network protocol, IP addressing, network security, required throughput and whether the interface is used for control, data exchange or system integration.

For deterministic control or high-throughput acquisition, evaluate the entire controller, chassis, network and application architecture rather than relying only on the Ethernet port speed.

CompactDAQ and CompactRIO Platform Compatibility

CompactDAQ systems are well suited to PC-based measurement, logging and portable test applications. Communication modules can be combined with analog, digital and sensor I/O when bus traffic must be correlated with physical measurements.

CompactRIO systems are used for embedded monitoring, real-time control and FPGA-based applications. Verify exact module support for the selected chassis, controller, operating mode and software environment before finalizing a CompactRIO architecture.

Review available Модули NI серии C when the system also needs analog input, analog output, digital I/O, temperature measurement or dynamic-signal acquisition.

Типичные применения

• Automotive CAN, CAN FD, LIN and FlexRay monitoring
• ECU development, validation and hardware-in-the-loop testing
• Battery-management-system communication and data logging
• Vehicle-network simulation and diagnostic-system development
• Industrial PLC, drive and motion-controller communication
• Serial instrument integration and legacy-equipment control
• Distributed test stands and automated validation systems
• Embedded monitoring and real-time control with CompactRIO
• Combined bus logging, sensor acquisition and event correlation

Communication Module Procurement and RFQ Guide

Часто задаваемые вопросы

What is the difference between CAN and CAN FD?

CAN FD extends classic CAN with support for larger payloads and, in supported systems, a faster data phase. The module, network nodes, software and application configuration must all support CAN FD when it is required.

Do CAN interfaces require termination?

Yes. A CAN network normally requires termination at its two physical ends. The correct termination value, wiring topology and cable arrangement should be verified against the system documentation.

Can an RS-485 device connect to an RS-232 module?

No. RS-232 and RS-485 use different electrical signaling methods. Select a module that matches the device’s actual interface standard.

Can I synchronize communication data with analog measurements?

Many systems can correlate network traffic with analog and digital measurements, but the available timing accuracy depends on the module, chassis, controller, driver and application design. Confirm synchronization requirements before selecting hardware.

Can C Series communication modules be used in CompactRIO?

Many C Series communication modules are intended for CompactRIO use, but compatibility varies by exact module, chassis, controller, software version and operating mode. Verify the specific part number before ordering.

Related NI Modular I/O Solutions

NI C Series Communication Modules from PXISOURCE

PXISOURCE helps engineers and procurement teams identify compatible NI C Series communication modules, review CompactDAQ and CompactRIO compatibility, match required accessories and source replacement hardware for existing automated-test and embedded-control systems.