The explosion-proof touch screen scale is operated according to a certain procedure. It achieves the process of ingredient measurement and control by controlling the pneumatic valves to introduce the materials into the corresponding "sealing", "compensation", "opening" and "empty space" four pipelines in sequence. It is a typical weighing control system. It uses manual valves and electromagnetic valves in parallel, and designs Electronic scales at the corresponding pipeline outlets to achieve fully automatic control. It automatically quantitatively controls the pneumatic valves of the material pipelines to discharge the materials in accordance with the pre-determined time sequence, and automatically completes a series of operations such as ingredient measurement, control, and re-ingredient measurement.

The explosion-proof scale is placed on the scale platform with the weighed object or load. Under the action of gravity, the scale platform transmits the gravity to the weighing sensor, causing the elastic body attached to the weighing sensor to deform. Then, the strain resistors and bridge circuit on the elastic strain beam lose balance, outputting an electrical signal proportional to the weight value. The signal is amplified by the linear amplifier and then converted into a digital signal by A/D conversion. The microprocessor in the weighing instrument processes the weight signal and directly displays the weight number. After being equipped with a printer, it can print the weighing data; if a computer is configured, the measurement number can be directly input into the weighing management system for comprehensive management.

The electronic scale can complete on-site ingredient control and formula weight collection through the HPS multi-material function installed on the touch screen. The on-site operator only needs to make necessary manual interventions to complete the entire production process, avoiding human errors and also improving production efficiency. It has rich functions such as production monitoring, formula management (with strong confidentiality), batch statistics, alarm prompts and report printing, and is very suitable for real-time and multi-task control. Through the corresponding communication interface, relevant production information can be uploaded to the data server or ERP to achieve information sharing.

According to the control requirements of the scale weighing, PLC is used as the lower-level control system, and the touch screen is used as the upper-level control system. PLC not only completes the logical control of various electromagnetic valves and weighing, but also communicates with the touch screen. The operation instructions are sent to the PLC through the RS-232 serial port by the touch screen. The instructions are processed by the control software of the PLC, controlled to run the weighing according to the process requirements, and transmitted to the analog input port of the PLC. After conversion to digital quantity, it is sent to the designated data register, and finally the touch screen displays the values in the data register. The transmission of various operation instructions is achieved by setting communication parameters between the touch screen and the PLC input ports. The touch screen is used as the upper-level control system, for scale start-stop operation, and can display various parameters during the operation process, achieving dynamic monitoring.