Two-Station Manufacturing Handshake

Engineering Context

Orion Robotics is connecting two manufacturing cells. Station A must never release a part until Station B is ready, and Station B must confirm receipt before Station A begins the next cycle. A failed signal could damage equipment or lose a product.

What You Will Practice

• Design machine-to-machine communication logic
• Represent a process with states and flowcharts
• Program confirmation and timeout behavior
• Validate communication under normal and fault conditions

What You Need

• Two connected VEX CTE workcells or a simulated two-station setup
• Object sensors
• Conveyors
• Signal tower
• Python projects
• Engineering notebook

Instructions

1. Define four signals: request, ready, transfer complete, and receipt confirmed.
2. Create a sequence diagram showing which station sends each signal.
3. Program Station B to announce ready only when its receiving zone is clear.
4. Program Station A to wait for ready before releasing a part.
5. Program Station B to confirm receipt after its sensor detects the part.
6. Add a timeout that stops both stations if confirmation does not arrive.
7. Run five normal transfers.
8. Simulate a blocked receiving zone and a missing confirmation; verify safe response.

Engineering Requirements

• Complete five consecutive normal transfers
• Never release into an occupied receiving zone
• Stop safely after a communication timeout
• Provide visible fault indication on the signal tower

Constraints & Safety

• No assumptions based only on elapsed time
• Each transfer requires positive confirmation
• Stations must start from a documented reset state
• Fault testing must use approved simulations only

What You Submit

• Handshake state/sequence diagram
• Station A and B code
• Normal and fault test log
• Reset procedure
• Reflection

Reflection Questions

1. Why are both ready and receipt signals needed?
2. What could happen if one station resets unexpectedly?
3. How did the timeout improve safety?
4. How would a PLC implement this handshake?