The NI USB-9481 is a 4-channel single-pole single-throw (SPST) relay device with a USB interface
The NI USB-9481 is a 4‑channel SPST relay device that connects to a computer via USB. This manual explains how to install the module, connect it to a PC, and operate it safely.
It also provides technical specifications, safety rules for handling hazardous voltages, LED indicator meanings, environmental compliance information, and contact details for technical support. This manual is written in Chinese.