3.3 Analog Input Connections
The differential input channels operate with two signal wires for each channel, and the voltage difference between both signal wires is mea- sured. There are 8 analog input channels available on USB-4718
Figure 3.2: Differential Input Channel Connection
3.4 Isolated Digital Input Connections
USB-4718 has 8 isolated digital input channels designated IDI0~IDI7. Each of isolated digital input channel accepts 5~30 VDC voltage inputs, and accept bi-directional input. It means that you can apply positive or negative voltage to an isolated input pin (IDI). All 8 input channels share one common pin. Figure 3-3 shows how to connect an external input source to one of the module’s isolated input channels
