LabVIEW 8.2 Analog Input Specifications

　　For devices that use both single-ended and differential input methods, the number of analog input channels can be divided into single-ended input channels and differential input channels. In single-ended input, the input signals are all based on a common ground line.

　　This input method is mainly used when the input signal voltage is high (greater than IV), the wire from the signal source to the analog input hardware is short (less than 5m), and all input signals share a reference ground wire.

　　If the signal does not meet these criteria, differential inputs should be used. With differential inputs, each input signal has its own reference ground; common-mode noise can be eliminated by the wires, thereby reducing noise errors. The sampling rate parameter determines the number of analog-to-digital conversions per second. A high sampling rate can collect more data in a given time, so it can better reflect the original signal.

　　Multiplexing (MUX) is a common technique for measuring multiple signals using a single analog-to-digital converter. Multiplexing uses a physical channel to transmit multiple signals simultaneously to improve channel utilization, so that a line can be used by multiple users at the same time without affecting each other. The multiplexer connects many low-speed lines and combines the transmission capacity required by each of them, and then transmits them on a higher-speed line. That is, the low-speed lines are merged at their far ends, and all information is transmitted by only one higher-speed line, rather than connecting many low-speed lines between a transmitter and a receiver.