Currently, domestic construction elevators are constrained by cost, resulting in outdated electrical control systems. Our designed construction elevator control system utilizes variable frequency drive and direct-call automatic leveling logic control, offering a comprehensive improvement in both passenger comfort and operator convenience. After hundreds of successful applications and continuous improvements, the system enjoys a high reputation among domestic peers. This article provides a brief introduction to the system based on Chengdu Yikong Automation Engineering Co., Ltd.'s years of experience in designing and debugging construction machinery control systems. We selected the most cost-effective Yaskawa inverter from Japan, ensuring smooth start and deceleration, near-zero speed braking, and a comfortable, shock-free ride. Variable frequency speed control is crucial in inverter selection; we chose the Yaskawa inverter commonly used in indoor elevators. Reliability is paramount when selecting an inverter, and Yaskawa is arguably the most stable inverter brand on the market. Elevator control requires high starting torque and precise braking control. Yaskawa's worldwide reputation in the lifting industry stems primarily from its widespread application in this sector, with each generation of products continuously improved specifically for the lifting industry. Yaskawa elevators can employ open-loop or closed-loop control. For construction elevators, unlike indoor elevators which require a leveling error within 10mm, open-loop control is perfectly adequate. The speed command method for the inverter is crucial, typically involving multi-speed input, potentiometer analog input, or bus input. Construction elevators operate in environments far more harsh than indoor elevators; therefore, we use the simplest and most reliable method: transmitting speed and control commands via the OCS-inverter communication interface. This minimizes wiring and maximizes stability. The leveling control logic is more demanding. We utilize a dedicated OCS logic control and operation display, featuring a HORNER-specific integrated OCS control display (PLC control + touchscreen + built-in network). This allows for operating temperatures from -20°C to +70°C, IP65 protection, 2GB of data memory, CsCAN bus communication, MODBUS master protocol, and an ultra-compact structure, making it ideal for the working conditions of construction machinery. The system's main logical functions include: direct floor calling, automatic leveling, status monitoring, inverter data monitoring, Chinese fault indication, and data storage and statistics. Automatic Leveling: Automatically operates after setting the target floor. It can be stopped or called at any time during operation. Upon reaching the target floor, it automatically decelerates and levels. An alarm bell automatically sounds upon start/stop. According to on-site measurements, at the same speed, the monthly operation frequency is increased by 120% compared to the original manual operation method. Automatic Judgment and Operation: Allows setting multiple target floors at once (keyboard input). The system automatically determines the direction and stops at the target floors in sequence; shortcut keys are also available for direct input of the upper, lower, and bottom floors. Emergency Handle Operation: An emergency handle operation mode is available, allowing for direct up and down movement, providing free operation during installation and floor lifting. Handle operation has priority; it can be operated independently even if the call system fails or if the automatic leveling system components are not installed or damaged. Electrical Protection: Comprehensive protection against undervoltage, overvoltage, overcurrent, overtorque, overspeed, rope breakage, upper and lower limits, terminal station speed limit, door interlock protection, automatic leveling detection sensor disconnection, and gate alarm detection. AC48V safety control voltage, 36V safety lighting voltage. Second Call Control Center (Optional): In addition to the in-car floor selection control, a second call control panel can be installed, such as on the ground floor. When used only for freight transport, elevator operation can be directly controlled from the ground floor. The second call panel still uses the HORNER electrical CsCAN bus connection, which is reliable and stable, unlike other single-chip RS485 network systems. CsCAN can guarantee a communication distance of 500 meters even in harsh environments. The second call panel only requires one communication cable to connect, allowing elevator calls via buttons, touchscreens, etc. Statistical Function: Equipped with a statistical function to record important parameters such as the elevator's start-up time, motor running time, and number of malfunctions throughout the rental period for reference by both the renter and lessee. With optional SD card data recording or optional wireless GPRS network monitoring, all data can be permanently stored in a database at the monitoring center. Fault Recording: Automatically records the time of fault occurrence and troubleshooting, as well as the fault code. The operation screen automatically prompts the driver in Chinese when a fault occurs, providing the cause of the fault and possible troubleshooting methods. Even momentary faults can be recorded and maintained on the screen, ensuring that any fault can be confirmed by the driver. Quick Program Replacement: OCS allows programs to be stored on an SD card. When a program replacement is needed, simply provide the SD card to the customer, who can then insert it into the OCS controller. GPS Positioning Function: Optional global GPS positioning function allows for real-time monitoring of equipment installation and distribution locations from the monitoring center. GPRS Monitoring Function: Optional nationwide GPRS network monitoring allows for display, alarm, and control from anywhere within China Mobile network coverage at the monitoring center. Real-time fault alarms and fault data transmission to the monitoring center allow the monitoring center to connect to any machine for observation at any time; remote setting of working time limits for shutdown, remote locking and unlocking of the elevator, and remote fault diagnosis capabilities provide immediate equipment fault alarms and remote guidance for maintenance workers to quickly handle faults. Summary Construction elevator frequency conversion control technology is mature, but the logic control principle is complex. A mature solution must refer to the design methods of indoor elevators while also considering the need for a simple external structure and ease of maintenance for construction elevators. Chengdu Yikong Automation Engineering Co., Ltd. has many years of experience in frequency conversion drive and control for lifting equipment. Whether you are purchasing products, integrating systems, or developing products, choosing us will provide you with the most professional service.