Webhooks in Industry 4.0: A guide to event-driven communication

1. How do Webhooks Work?

1. Event occurs (e.g., new order, threshold exceeded)
2. System automatically sends HTTP request to predefined URL
3. Target system receives data and responds accordingly
4. No manual queries needed

2. Webhooks vs. Conventional APIs: The Crucial Difference

Webhooks and APIs are two different types of communication between applications:

• APIs work like a phone call, an app actively calls and asks: “Do you have new emails for me?”
• Webhooks are like an SMS notification, they come automatically: “You have received a new email!”

For example, an online shop wants to inform accounting software about new orders. With an API, the accounting system would have to constantly ask. With a webhook, the shop reports itself as soon as an order comes in.

APIs are ideal for scenarios where you need to actively query and retrieve data and want more control over the interaction. Webhooks, on the other hand, are better suited when you need updates in near real-time and want to receive information as soon as an event occurs, without constantly asking for it.

3. Why Webhooks are Essential in Industry 4.0

Main advantages for industrial companies:

• Immediate reactions: Machine failures, quality deviations, or supply bottlenecks are reported in real-time.
• Automated processes:
  • Inventory falls below minimum → Automatic reorder
  • Quality inspection failed → Immediate notification to quality assurance
  • Machine maintenance due → Automatic scheduling
• Cost savings: Up to 90% less network traffic compared to constant API queries.
• Seamless integration: Connection between OT (Operational Technology) and IT systems without media breaks.

4. Security with Webhooks: What You Need to Consider

Essential security measures:

• Encryption:
  • Use HTTPS exclusively
  • TLS 1.3 for maximum security
  • Mutual TLS (mTLS) for critical applications
• Authentication:
  • HMAC signatures to verify the sender
  • API keys for access control
  • OAuth 2.0 for advanced security requirements
• Validation and monitoring:
  • JSON schema validation of all incoming data
  • Rate limiting against DoS attacks
  • Comprehensive logging of all webhook activities

5. OPC Router: Your Webhook Hub for Industry 4.0

What makes OPC Router the ideal webhook solution?
OPC Router functions as a central middleware platform for industrial data integration. With the integrated REST plugin, it becomes the control center for event-driven communication.

Core functions:

• Bidirectional webhook support:
  • Incoming: Cloud services send data to production systems
  • Outgoing: Machines automatically trigger IT processes
• Graphical configuration:
  • No programming required
  • Drag-and-drop interface for data flows
  • Real-time monitoring of all transfers
• Industrial-grade reliability:
  • Automatic retry mechanisms
  • Exponential backoff for connection errors
  • Dead letter queues for lost messages

6. Practical Use Cases in Industry 4.0

1. Predictive Maintenance: Scenario: Vibration sensor detects anomaly → Webhook action: Automatic maintenance order creation in CMMS system
2. Supply Chain Automation: Scenario: Raw material inventory reaches minimum level → Webhook action: Immediate order with supplier via ERP integration
3. Quality Management: Scenario: Measured value is outside tolerance → Webhook action: Production line stop + notification to quality assurance
4. Energy Monitoring: Scenario: Power consumption exceeds limit → Webhook action: Load management system activates energy-saving measures

7. Frequently Asked Questions about Webhooks

8. Conclusion: Webhooks as a Catalyst for Industry 4.0

Webhooks revolutionize industrial communication through event-driven automation. They eliminate inefficient polling, reduce latency, and enable true Industry 4.0 scenarios.
OPC Router with REST plugin makes webhooks accessible for any production environment, without programming effort, with industrial-grade reliability and seamless integration into existing IT/OT landscapes.
Start your webhook integration now and benefit from efficient, automated, and future-proof industrial communication.

9. Technical Terms Explained

Polling: Regular query of an application to check if new data is available – inefficient and resource-intensive.

HMAC: Hash-based Message Authentication Code – cryptographic method for verifying message integrity.

Dead Letter Queue: Storage for undeliverable messages for later processing.

Exponential Backoff: Strategy for retrying failed requests with exponentially increasing wait times.