Current plan
There are currently two control schemes:

1. Industrial control board + input sensor + output driver + communication unit

Industrial control boards include industrial control computers, single-board computers, PLC, integrated HMI+PLC and other control methods. The advantages are stable and reliable, the software can be built quickly, and the configuration is flexible, the development speed is fast, and the disadvantages are high in cost.

The input sensor is divided into analog quantity and digital quantity. The analog quantity has digital type and analog type. The digital quantity is mainly high and low two-bit signals.

There are two types of output drivers: transistor and relay output. The transistor is small but the heat sink is not small, there is no electric shock wear, no sound, PWM output can be used, the disadvantage is too expensive. The relay output is divided into signal points and power output (contactor).

The communication unit (RTU) is divided into short-range (WIFI/BLUE/ZIGBEE/LORA), long-range for mobile operators (3/4/5G), and similar power wireless private networks.

2. Microprocessor (ARM/DSP/MCU) + HMI panel + peripheral IO input and output + communication unit. The overall components are made on a circuit board and the cost is lower, and it is suitable for small household ordinary electric boilers, Peninsula electric boilers, electromagnetic electric boilers and other products that are sensitive to cost.

The above control schemes all have automatic control functions such as high and low water temperature control, water level and flow control, supply and return water temperature detection, water shortage protection, over temperature protection, pressure protection, multi-stage timing control, auxiliary function leakage protection, door opening protection, and power restart protection.