National Instruments NI-9881 C Series CANopen Interface Module

The National Instruments NI-9881 (Part Number: 781673-01) is a CANopen Interface Module. This high-speed CANopen Interface Module is designed to be utilized for CANopen applications on CompactRIO hardware. CANopen on top of the CAN physical layer generally used for industrial automation-related applications, such as maritime electronics, off-road vehicles, medical equipment, building automation, public transportation, etc. This model can transmit as well as receive PDOs (process data objects) and SDOs (service data objects) according to the requirements of CiA DS 301.

The National Instruments NI 9881 C Series Module comes with 1 CANopen channel and offers up to 1 Mbits/s maximum baud rate. To connect to a CAN bus, this device comes equipped with one 9-pin, D-Sub male connector. The port contained by the NI 9881 has two common pins. These common pins are internally connected to the isolated reference of the module and they act as the reference ground for CAN_L and for CAN_H. In this configuration, the user can also have the CAN bus reference ground connected to either one or both common pins.  The port included in this CANopen Interface Module has an optional shield pin (SHLD) as well. In some cases, connecting to SHLD may assist the user with improving EMC performance and signal integrity in a noisy environment.  

For Hi-Speed CAN transceivers, this module features software-selectable bus termination. On the National Instruments NI-9881, the user can utilize an API call to switch on 120 Ω termination resistors between CAN_L and CAN_H.