Bakery — Cold Chain Monitoring

This use case shows how an industrial bakery connects its frozen dough freezer to Rela to monitor the cold chain and receive automatic alerts when the temperature goes out of the safe range.

Scenario

La Espiga Bakery has an industrial freezer where it stores frozen dough at -18 degrees C. Regulations require that the temperature stays between -22 degrees C and -16 degrees C. If the temperature rises above -16 degrees C for more than 15 minutes, the product may be compromised.

Currently, a technician checks the temperature manually every 2 hours. They want to automate the monitoring and receive immediate alerts.

Step 1: Connect the temperature sensor

The freezer has a PLC with Modbus TCP output. The technician configures an event source in Rela:

1. Go to Data -> Event Sources -> New Source
2. Select protocol: Modbus TCP
3. Configure:
   • IP: 192.168.1.50
   • Port: 502
   • Register: 40001 (holding register with temperature)
   • Reading frequency: every 60 seconds
   • Name: "Frozen Dough Freezer"
4. Associate to asset: "Warehouse A Freezer"

Step 2: Enable cold chain

1. Go to Assets -> Warehouse A Freezer -> Edit
2. Enable Cold Chain
3. Configure:
   • Minimum temperature: -22 degrees C
   • Maximum temperature: -16 degrees C
   • Grace period: 15 minutes

Step 3: Configure notifications

The responsible technician already has WhatsApp configured in Rela. Cold chain notifications are sent automatically when:

• An excursion is detected (warning)
• The excursion exceeds the grace period (critical)
• The excursion is resolved (temperature returns to range)

Step 4: Day-to-day operation

Normal operation

The sensor sends a reading every 60 seconds. Rela receives the data, stores it, and verifies it is within the range [-22, -16]. In the cold chain dashboard, the freezer appears in green with its current temperature.

Excursion detected

On Saturday at 3:00 AM, the freezer door was left improperly closed. The temperature starts to rise:

• 3:00 AM — Temperature: -15.8 degrees C (out of range) -> Excursion created with "warning" severity
• 3:01 AM — The technician receives WhatsApp: "Temperature excursion at Warehouse A Freezer. Current temperature: -15.8 degrees C (limit: -16 degrees C). Grace period: 15 min."
• 3:10 AM — Temperature: -14.2 degrees C. Peak deviation updated.
• 3:15 AM — Grace period expired. Severity escalates to "critical". Second WhatsApp: "CRITICAL: Excursion at Warehouse A Freezer for 15 min. Temperature: -13.8 degrees C. Action required."
• 3:20 AM — The technician arrives, closes the door properly.
• 3:35 AM — Temperature returns to -16.5 degrees C. Excursion resolves automatically. WhatsApp: "Excursion resolved at Warehouse A Freezer. Duration: 35 min. Peak deviation: 3.8 degrees C."

Result

Everything was recorded automatically:

• Excursion with duration, peak deviation, and resolution
• Notifications sent with timestamps
• Available in cold chain reports

Without Rela, nobody would have known until the manual check at 4:00 AM — or worse, until Monday.