Project Overview: Engine testing is a crucial and complex component of automotive testing. Significant variations in temperature, pressure, and gas content during testing place higher demands on laboratory air conditioning control. System Requirements: 1. Experimental Requirements: When the Siemens system sends a start test signal, the system automatically enters test mode. In this mode, all air valves open according to pre-set opening degrees, delivering airflow at the set volume and temperature. If a door is opened, the exhaust fan will stop speed adjustment; after the door closes, the exhaust fan motor will adjust its speed to maintain a negative pressure environment (approximately -20 Pa) inside the room. The powerful cooling fans inside the room will turn on, and the corresponding fan and chilled water coil valves will adjust their opening degrees according to the room temperature to regulate the room temperature. 2. Disassembly/Assembly Requirements: When the Siemens test signal stops, the system automatically enters disassembly/assembly mode. Similar to the test mode, all components will automatically operate according to pre-set values. However, the exhaust fan motor only operates at the set speed, and the fan will automatically stop when the room temperature is low and automatically turn on when it is too high (configurable). 3. Manual Control Requirements: When the Siemens test signal stops, clicking the switch (upper left) in the diagram enters manual mode. In this mode, the operating status of each actuator can be manually set; fire dampers are uncontrollable. 4. Stop: After stopping/starting, all air dampers and fire dampers must close, all water valves must open, and all motors will stop working. The system will then enter a state of minimum power consumption, primarily for equipment maintenance or long-term leave. Solution: This control system is for the automatic air conditioning control of laboratories 5, 6, and 7. Its main function is to stabilize the internal temperature and pressure of the laboratories and can be linked with the fire protection system, gas detection system, and Siemens testing equipment via signal lines. The lower-level control uses a WAGO PLC and corresponding modules manufactured by WAGO GmbH, Germany, while the upper-level control uses Turingcontrol configuration software. Operation Status: The system was put into operation in 2005. Its stable and reliable operation has solved the problem of complex changes in the engine testing environment and has been highly recognized by FAW-Volkswagen.