Application Notes

The heart of any industrial or domestic control device is either a microcontroller, a PLC (Programmable Logic Controller) or an IPC (Industrial PC). It handles the data processing, logic control, and interfacing. The latter includes digital inputs and outputs for status and PWM signals, switches or relays. Analog inputs measure variables such as temperature, brightness or frequency, while the outputs provide signal voltages or currents. Communication with other devices works via special interfaces such as Profibus, Profinet, EtherNet/IP, CANopen, Modbus or KNX. The power supply runs on typical input voltages of 24 VDC, 48 VDC or 110/230 VAC; sometimes, communication data are transferred via the power line itself.

Diotec provides dedicated semiconductor components acting between the microcomputer device and its surrounding. This Application Note introduces it.