Level Alarm Stack (First-Out)

Briefing

A tank level alarm stack monitors four setpoints: High-High (>95%), High (>80%), Low (<20%), and Low-Low (<5%). Each alarm latches its indicator lamp. The lamp blinks until acknowledged (ACK_PB), then stays solid. HH and LL alarms also assert SHUTDOWN. The HORN sounds on any unacknowledged alarm and is silenced by ACK_PB. RESET_PB clears all latched alarms once all process conditions have cleared.

Objectives

• LEVEL_HIGH_HIGH asserts HH_LAMP (blinking until ACK) and SHUTDOWN
• LEVEL_HIGH asserts H_LAMP (blinking until ACK)
• LEVEL_LOW asserts L_LAMP (blinking until ACK)
• LEVEL_LOW_LOW asserts LL_LAMP (blinking until ACK) and SHUTDOWN
• ACK_PB silences HORN and transitions all blinking lamps to steady
• RESET_PB clears all latched alarms when all level inputs are clear

I/O Table

Your program will be tested against:

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

1. #1Level through HH threshold asserts HH_LAMP and SHUTDOWN

   LEVEL_HIGH_HIGH trips — HH_LAMP, HORN and SHUTDOWN assert

2. #2ACK_PB silences HORN but lamps stay on

   Acknowledge active alarm — horn silences, lamps remain asserted

3. #3LEVEL_HIGH asserts H_LAMP (independent of HH)

   Manually trip H alarm — H_LAMP asserts without SHUTDOWN

4. #4LEVEL_LOW_LOW asserts LL_LAMP and SHUTDOWN

   Trip LL alarm — LL_LAMP latches and SHUTDOWN asserts

5. #5RESET_PB clears all alarms when all level inputs are clear

   Trip H alarm then clear level input and reset — lamp clears