The switching device is composed of a coil, normally open contacts, normally closed contacts, a counteracting spring, a reset spring, and a housing. The switching device includes Switching Device A and Switching Device B. Switching Device A and Switching Device B achieve electrical self-locking and interlocking, controlling the detection channel and the weighing channel, alternatively connecting or disconnecting.
When switching device A is turned on, the detection channel is connected and self-locked to carry out the detection work, collecting the output signals of each weighing sensor; at this time, switching device B is interlocked and disconnected, the weighing channel is disconnected, and weighing work cannot proceed. Conversely, when switching device B is turned on, the weighing channel is connected and self-locked to carry out weighing measurement; at this time, switching device A is interlocked and disconnected, the detection channel is disconnected, and detection work cannot proceed.
When switching device A and switching device B are connected for self-locking, both use two identical normally open contacts connected in parallel; when switching device A and switching device B are interlocked to disconnect, both use two identical normally closed contacts connected in series. This kind of backup design can improve the reliability of system operation.
The self-diagnostic weighing controller includes a detection module, weighing module, setting input module, display module, and alarm module. The self-diagnostic weighing controller is connected to the display module through the detection module to display the weighing output values of each weighing sensor under no-load, empty scale, and calibration conditions; the self-diagnostic weighing controller is connected to the alarm module through the detection module to indicate when each upgraded weighing sensor or weighing channel is in a fault-critical state; the self-diagnostic weighing controller is connected to the lifting device through the alarm module to complete the collection of no-load output values of each weighing sensor.
Connect the detection channel. One end of the normally open contacts KA1 and KA2, after being redundantly connected in parallel, is connected to the weighing sensor via a cable, and the other end is connected to the detection port of the self-diagnosing weighing controller via a cable.
The self-diagnosis testing module collects the initial no-load values, initial empty scale values, and initial calibration values of each weighing sensor as their respective standard initial values for storage. At the same time, combined with the technical indicators and technical parameters of the weighing system (such as range, actual scale interval, and number of divisions), and based on verification standards, it determines the fault critical threshold of each weighing sensor in different weighing segments (taking a medium-accuracy scale as an example). Additionally, the monitoring threshold can be appropriately adjusted according to the actual operational conditions. The standard initial values are the main reference values for calculation and self-learning carried out by the self-diagnosis weighing controller.
In the empty scale state, press the 'Detection' button. The self-diagnosing weighing controller collects the current empty scale values from each weighing sensor. At this time, the current empty scale values are compared with the initial empty scale values. When they reach the critical threshold of the corresponding weighing range, the alarm module will cause the digital numbers to flash or trigger an audible and visual alarm in the corresponding 'Detection Display Window'.
When checking the empty scale, the detection is normal. When the same weighing load is applied and the 'Check' button is pressed, the 'Check Summary Display Window' shows the theoretical measurement value of the weighing load. Compared with the actual measured value of the weighing load displayed in the 'Weighing Display Window' when the 'Weigh' button is pressed, if the difference is ≥ (compensation value + critical threshold), the self-diagnosing weighing controller will issue an alert, indicating that the analog junction box or wiring of the weighing channel is in a fault-critical state, allowing for quick diagnosis of the faulty part of the weighing system.
When the 'Intelligent Detection Weighing' button is pressed, the weighing system enters an intelligent loop state of detection, fault diagnosis, and weighing operations. The cycle frequency of weighing and detection is intelligently selected based on the detection results. When the number of alarm prompts increases, the frequency of detection also increases. Conversely, the frequency of weighing increases. The system intelligently performs real-time self-diagnosis for each weighing sensor and weighing channel while completing weighing tasks, promptly providing alerts and confirmations when abnormalities occur.
