National Instruments 778985-01 4-Channel Serial Interface Module 

The part number 778985-01 from National Instruments is the identifying part number for the PXI-8431/4  4-channel serial interface module. This module has 4 channels that support RS-485 and RS-422 communication standards. The 778985-01 module is designed to be compatible with the PXI and CompactPCI systems by National Instruments. The RS-485 protocol is great for providing long-range communication with noise immunity and the RS-422 protocol allows the module to perform high-speed communication over a short distance. The module has flexible baud rates ranging from 57 baud to 3000000 baud, providing high-speed communication. 

This serial interface module has a data speed of up to 3 Mbps allowing the data transfer to be quick and handled efficiently without zero to minimal data loss during communication. This module also has a 128 bytes FIFO buffer memory on each channel allowing for smooth communication without data loss by storing the data temporarily during data bursts or communication irregularities. Each channel has a voltage rating of 5 volts DC, with a current rating of 725 milliamperes. The module has a max cable length of 1.2 km per port with 31 devices connected to each port. The device allows interrupt sharing between the ports and also allows for Direct Memory Access for connected devices to access the main system memory or RAM independently of the central processing unit.

To configure and control the module via your computer, the 778985-01 module is compatible with National Instruments's software tools, such as LabVIEW, NI-VISA, and Measurement & Automation Explorer (MAX). Using these applications users can set up communication protocols of their choice, debug and detect communication errors, etc. This module is also compatible with both Linux and Windows operating systems. 

The 778985-01 module has an operating temperature between 0 degrees Celsius to 55 Degrees Celsius, making it suitable for harsher industrial environments. The module can also withstand a humidity rating of between 17% to 85% Noncondensing. The module is fairly compact with a length of 16 cm and a width of 10 cm and supports a 10-position modular jack I/O connector.