A Stacker Crane Driving System Based on DeviceNet Stacker cranes are the main handling equipment in automated warehouses (AS/RS). They shuttle back and forth in the aisles of high-rise racks, responsible for storing and retrieving goods. Currently, the most widely used type is the aisle-type stacker crane, which consists of five parts: a running mechanism, a lifting mechanism, a loading platform equipped with storage and retrieval mechanisms, a frame, and electrical equipment. Currently, stacker cranes can operate at speeds up to 320 m/min, with lifting speeds up to 60 m/min, and positioning accuracy better than ±5 mm. DeviceNet, proposed by Rockwell Automation in 1994, is an open fieldbus network and has become an international industrial automation network standard. DeviceNet provides deterministic and reliable network connections and data communication for simple industrial equipment (sensors, frequency converters, etc.) and high-end equipment (PLCs, computers). DeviceNet provides master/slave and peer-to-peer network communication capabilities and a producer/consumer service model, allowing devices on the DeviceNet network to be removed or replaced online without any programming tools. Packets originating from ControlNet, DH+, or Ethernet links can be sent to all nodes on the DeviceNet link via the ControlLogix gateway. Using DeviceNet reduces the amount of cabling required for device communication, lowering the manpower and wiring costs of system setup. It also provides users with complete device-level diagnostics, facilitating network maintenance. Previously, frequency converters had limited communication capabilities, requiring offline optimization control of asynchronous motors based on specific mathematical models and optimal conditions. When motor parameters and operating conditions changed, continuing to use the original frequency converter parameters failed to achieve the desired optimization results. DeviceNet allows frequency converters to be connected to the control network, enabling online monitoring and optimization, improving the positioning accuracy of stacker cranes, and saving significant energy. II. Control System Hardware Design The control system mainly utilizes SLC500 and PLC5 controllers, 1747-SDN scanners, 1771-SDN scanners, and a 1203-GK5 communication interface, configured into a DeviceNet control network to control the 1336PULS II frequency converter. The DeviceNet network is connected to the host computer via a 1770-KFD interface module. The scanners serve as the interface between the PLC and DeviceNet, their main function being to sample and convert device data formats. All data exchange between the PLC and the device is achieved through the scanners. The SLC500 and PLC5 can be connected to DeviceNet via the 1747-SDN scanner and 1771-SDN scanner, respectively. The 1336PULS II frequency converter is connected to the SCANport interface of the DeviceNet communication module 1203-GK5 via its SCANport interface. This establishes a DeviceNet motor control network, the network structure of which is shown in Figure 1. Human-Machine Interface Design for Three Control Systems 1. RSView32 Software RSView32 is a comprehensive, component-based human-machine interface development software that can be used for real-time monitoring and control of automated equipment and production processes. It is the first human-machine interface software with the following characteristics: (1) It opens the graphical interface as a container for ActiveX controls, enabling convenient expansion of RSView32 projects through reusable and customizable ActiveX controls that can be directly integrated into the user's graphical interface; (2) It can easily work with other component-based software products using the object model; (3) It integrates Microsoft's Visual Basic for Applications (VBA) as a built-in programming language; (4) It supports OPC (OLE for process control), enabling fast and reliable communication with products from other automation vendors; (5) It uses Add-On Architecture technology to extend the functionality of RSView32, allowing new features to be directly integrated into the RSView32 kernel; (6) It can utilize the Active Display System to achieve remote monitoring. 2. Overall Functional Structure of the Human-Machine Interface The overall functional structure of the human-machine interface is shown in Figure 2. The main interface allows for daily system monitoring and access to various sub-interfaces. The manual control panel sub-interface has six motor control buttons, which, combined with the status display area of ​​the main interface, enable manual control of the inverter and motors. The circuit diagnostic diagram sub-interface simulates and monitors the connection and operating status of the system hardware circuits in real time. The 1336PLUS II inverter configuration sub-interface allows for the configuration of all relevant parameters of the inverter. 3. Main Interface Design The main software interface is divided into a real-time animation display area, a real-time speedometer, a function button area, a speed input box, a motor status display area, a speed curve graph, and a speed drag bar. The real-time animation display area dynamically displays the speed and position of the lifting platform in real time. The real-time speedometer displays the speed value and unit (r/min) in real time. The function button area has four buttons: Auto, Manual, Diagnostic, and 1336PLUS II Inverter Configuration. The Auto button controls the lifting platform to move up and down automatically once. Pressing the Manual button displays the Manual Control panel. Pressing the Diagnostic button displays the circuit diagnostic diagram. Pressing the 1336PLUS II Inverter Configuration button displays the inverter parameter adjustment table. The speed input box allows precise adjustment of the motor speed, with an adjustable range of 0–1430 r/min (available only in manual mode). The motor status display area has nine indicator lights: Auto, Manual, Alarm, Run, Forward, Jog, Stop, Reverse, and Fault. A green indicator light indicates the motor is in that state, while gray indicates the opposite. The speed curve graph displays real-time speed changes during motor operation. In manual mode, the speed slider can be used to coarsely change the motor speed, and a minimum frequency (8Hz) setting protection is available. The system's main interface is shown in Figure 3. During the development of the main interface, it was discovered that the data source for the S-curve is the [Freq Command] in the inverter's [Metering] group, which needs to be read via an M-file. The sampling period is too long, failing to meet the real-time sampling requirements of the S-curve, resulting in an uneven, broken line in the trend chart. Further analysis revealed that this was mainly due to the low sampling frequency and discontinuous data. To obtain a smooth S-curve, the data sampling frequency must be increased. Therefore, we utilize the automatic refresh and real-time performance of I/O mapping, using the [word1 frequency feedback value] of the input mapping as the data source for the S-curve. Furthermore, the data sampling frequency is also related to the Tag scan time and the scan time in the trend chart. By setting the Tag Scan Class scan period and the Rate in the trend chart to 0, RSView32 will scan the frequency feedback value in real-time at the fastest speed, obtaining a very smooth S-curve. 4. Manual Control Panel Sub-Interface Design The manual control panel has 7 buttons. These are Run, Stop, Jog, Clear Faults, Reverse, Forward, and Close. During motor operation, the Run, Jog, Reverse, and Forward buttons will be disabled; pressing these buttons will have no effect. 5. Circuit Diagnostic Diagram Sub-interface Design The circuit diagnostic diagram is based on the hardware circuit diagram, using red lines to connect online devices and black lines to connect devices that may be faulty or have been removed from the network. This interface has two buttons: a Virtual button to simulate the hardware connections of the system, allowing users to simulate circuit connection status and check the correctness of the circuit connection logic; and a Monitor button to monitor the system hardware connection status in real time, greatly improving the efficiency of system fault diagnosis and hardware maintenance. 6. 1336PLUS II Inverter Parameter Configuration Sub-interface Design Pressing the Config 1336II button on the main interface will display an upload parameter progress bar. After the parameters are uploaded, the inverter parameter adjustment table will display the parameter setting dialog box [1336 PlusII Parameter Settings]. At this time, you can set all inverter parameters individually by group. Below the parameter adjustment table are five buttons: Refresh Specified Parameter, Refresh All Data, Refresh Group, Download Parameters, and Return to Main Window. IV. Conclusion Leveraging the powerful functions of RSView32 software, this user interface was designed and implemented. It is flexible, simple to use, and offers multiple control modes including automatic and manual operation. It clearly displays operation steps and equipment operating status, making it easy for even beginners to operate. System maintenance is also convenient and quick.