Let's break down the sequence as described and create a step-by-step GRAFCET (sequential function chart) solution. --- ### **Step-by-Step Solution (with GRAFCET Steps)** #### **1. Initialization (Step 0)** - **Condition:** System is idle, waiting for the "start push button" to be pressed. - **Transition:** When the start button is pressed. #### **2. Move Box Conveyor (Step 1)** - **Action:** The box conveyor moves. - **Transition:** When a box is detected by the sensor at the loading station. #### **3. Stop Box Conveyor, Start Apple Conveyor (Step 2)** - **Action:** - Stop the box conveyor. - Start the apple conveyor. - Reset apple counter (S1) to 0. - **Transition:** When the apple counter (S1) reaches 10 (10 apples have been loaded). #### **4. Stop Apple Conveyor, Start Timer (Step 3)** - **Action:** - Stop the apple conveyor. - Start a 10-second timer. - **Transition:** When the timer reaches 10 seconds. #### **5. Start Box Conveyor Again (Step 4)** - **Action:** - Start the box conveyor. - **Transition:** When the box moves out of the detection area (box no longer present), go back to Step 1. #### **6. Stop Condition (Step 5)** - At any step, if the "stop push button" is pressed, all operations stop, and the system returns to Step 0. --- ### **GRAFCET Diagram (Textual Representation)** ``` [Step 0] ---[Start Button Pressed]---> [Step 1: Box Conveyor Moves] | |<---[Stop Button Pressed]--- (any step) [Step 1] ---[Box Detected]---> [Step 2: Box Conveyor Stops, Apple Conveyor Starts, S1=0] [Step 2] ---[S1=10 Apples]---> [Step 3: Apple Conveyor Stops, Timer Starts] [Step 3] ---[Timer=10s]---> [Step 4: Box Conveyor Starts Again] [Step 4] ---[Box Out of Detection]---> [Step 1] ``` --- ### **Explanation** 1. **Start**: The process starts with the push of the start button. 2. **Box Conveyor Moves**: The box conveyor moves to place a box under the apple conveyor. 3. **Box Detected**: When a box is detected, the box conveyor stops, the apple conveyor starts, and the apple counter S1 starts counting apples. 4. **10 Apples Loaded**: When 10 apples are loaded (S1 = 10), the apple conveyor stops, and a 10-second timer starts (allowing apples to settle). 5. **Timer Ends**: After 10 seconds, the box conveyor starts again, moving the filled box away and positioning a new box. 6. **Repeat**: The process repeats for the next box unless the stop button is pressed, which halts the entire system. --- ### **Final Answer (Summary Table)** | Step | Action | Transition Condition | |------|------------------------------------------------------------|---------------------------------------| | 0 | Wait for start button | Start button pressed | | 1 | Box conveyor moves | Box detected by sensor | | 2 | Box conveyor stops, apple conveyor starts, S1 resets | S1 counts 10 apples | | 3 | Apple conveyor stops, 10-second timer starts | Timer = 10 seconds | | 4 | Box conveyor starts again | Box moves out of detection area | | Any | All operations stop | Stop button pressed | --- **This GRAFCET sequence ensures the process is automated and repeatable, with clear start/stop conditions, and meets the requirements of the industrial process described in the problem.**