National Instruments NI-9871 C Series Serial Interface Module

The National Instruments NI-9871 (Part Numbers: 779892-01, 779892-02, 779892-03) is a 4-Port, RS485/RS422 Serial Interface Module designed to add serial ports to CompactRIO systems. In this model, the serial ports can be accessed directly from the FPGA to bring users the flexibility required in communicating with serial devices. The NI 9871 module comes with individual buffers on each of its ports that simplify programming and save FPGA space. Also, the module can be programmed using the LabVIEW Full Development System for Windows. This module offers a standard start/stop bit and handshaking settings and utilizes an external power source to provide users with maximum achievable reliability and compatibility under all serial port conditions.

The National Instruments NI-9871 is offered in two variations, which are; part number 779892-02 without conformal coating, and part number 779892-03 with conformal coating. Part number 779892-01 is the version of the NI-9871 that comes with 4 10P10C-DE9 Cables that are 1 meter in length. The conformal coated version brings additional protection from moisture. This Serial Interface Module comes with impressive specifications as it offers 3.6864 Mbps maximum baud rate, ±15 kV data line ESD protection, and allows up to 1.2 km (4,000 ft.) maximum cable length. This module consumes 0.5 Watts of power (max) in active mode and 50 μWatts of power (max) in standby or sleep mode. In addition, the NI 9871 4-port module consumes 3.5 Watts of power (max) from +8 to +28 VDC external power supply.

 This device is designed to offer 60 VDC continuous, port-to-earth ground isolation and has been tested to offer up to 1000 Vrms withstand isolation. To connect to an externally located power source, the NI-9871 comes equipped with four-position, female pigtail. The four RS485/RS422 ports incorporated in this module operate in complete isolation from the other modules. Additionally, the device is equipped with a DB-9 male front panel connector.

The NI device weighs 5.4 oz. It has a recommended operating temperature range of –40 to 70 °C, a storage temperature range of –40 to 85 °C, non-condensing operating and storage humidity ranges of 10 to 90% RH and 5 to 95% RH respectively, and random and sinusoidal operating vibrations of 5 grms and 5 g respectively–all at a frequency range of 10 to 500 Hz.