Digital input and analog input module
The digital module and analog module are both signal points transmitted from external devices to the PLC. They both belong to the function of input modules and are commonly used modules in our PLC system. To understand their differences, let’s first understand what they do.
Digital input module
Another alias for digital quantity is switch quantity, which means on and off, 0 and 1. Digital input modules are commonly used for external button switches and other devices, and the feedback of device operation also belongs to the switch quantity point and is integrated into the digital quantity module.
Analog input module
Analog signals are the process values in our production process, and the monitored physical process values are converted into standard current or voltage signals through transmitters, which are input into our analog module. For example, monitoring temperature changes during the production process, 0-100 ℃, is then converted into signal modes supported by the analog module through conversion circuits, such as 4-20mA. In this way, the analog module is processed and transmitted to the CPU for program control.
