3-Way Sortation Diverter

Briefing

An extension of the 2-way sortation diverter with a third lane. Each item passes a photoeye and carries exactly one tag (TAG_A, TAG_B, or TAG_C). After a 500 ms travel delay the correct diverter solenoid energises for 1 s to route the item into the corresponding lane. Multi-tag reads (more than one tag high) or zero-tag reads latch ERROR_LAMP. STOP_PB clears the error and halts the conveyor.

Objectives

• CONV_RUN is on whenever the system is running (not stopped)
• On PHOTOEYE_IN rising edge, latch tag values; validate exactly one tag set
• After 500 ms travel delay, energise the correct diverter (A, B, or C) for 1 s
• Multi-tag or zero-tag reads latch ERROR_LAMP and suppress diverter action
• ERROR_LAMP latches until STOP_PB is pressed with all tags de-asserted

I/O Table

Your program will be tested against:

All test cases run automatically when you submit. Assertions are hidden until you pass.

1. #1CONV_RUN on by default, stops on STOP_PB

   Conveyor runs immediately; STOP_PB drops it

2. #2TAG_A item activates DIVERTER_A after 500ms

   Single TAG_A read routes item to lane A

3. #3TAG_C item activates DIVERTER_C

   Single TAG_C read routes item to lane C

4. #4TAG_B item activates DIVERTER_B after 500ms

   Single TAG_B read routes the item to lane B without energising either neighbouring diverter

5. #5Multi-tag read latches ERROR_LAMP

   TAG_A and TAG_B both set causes error; STOP_PB clears

6. #6Zero-tag read latches ERROR_LAMP

   No tag asserted when photoeye fires causes error