| Feature/Function | SCADA Systems | OPC Servers | Middleware | IoT Platforms | Data Historians | Industrial Routers and Gateways | Communication to PLCs |
|---|---|---|---|---|---|---|---|
| Definition | Real-time monitoring and control software. | Standardize data communication between devices. | Intermediary software for system communication. | Connect and manage IoT devices and sensors. | Record and process industrial data. | Connect different industrial networks. | How systems interact with PLCs. |
| Connectivity | PLCs, RTUs, sensors via industrial protocols. | Wide range of industrial equipment. | Disparate software systems and applications. | IoT devices via internet protocols. | Industrial control systems for data collection. | Diverse industrial networks and devices. | Communication protocols and physical connections to PLCs. |
| Communication Methods | Ethernet, serial (RS232/RS485), fieldbuses like Modbus, PROFIBUS. | OPC DA, OPC UA over Ethernet, serial. | HTTP, MQTT, AMQP, proprietary protocols. | MQTT, AMQP, HTTP, CoAP, WebSocket. | OPC, Modbus, custom protocols. | Ethernet, Wi-Fi, serial, VPN, firewall functionalities. | Direct or networked communication, often via Ethernet or serial connections. |
| Wiring Components | Ethernet cables (RJ45), Serial cables (RS232/RS485), Fieldbus connectors. | Ethernet (RJ45), Serial (RS232/RS485). | Ethernet (RJ45), potentially wireless. | Ethernet (RJ45), Wi-Fi components. | Ethernet (RJ45), Serial (RS232/RS485). | Ethernet (RJ45), Serial (RS232/RS485), Fiber Optic. | Depends on the PLC model and network architecture. |
| PLC Communication | Directly to PLCs or via intermediate devices like gateways. | Communicate with PLCs via server-client model. | Facilitates data flow between PLCs and other systems. | Indirectly through gateways or networked PLCs. | Collects data from PLCs for historical analysis. | Bridges PLCs with different network protocols. | Involves both hardware interfaces and communication protocols. |
Additional Notes:
- PLC Communication Protocols: Common protocols for PLC communication include Modbus (RTU, TCP), PROFIBUS, PROFINET, Ethernet/IP, and others. The choice depends on the PLC’s capabilities and the system requirements.
- Physical Connection: The type of physical connection (Ethernet, RS232, RS485, etc.) depends on the PLC’s available ports and the distance of communication. Ethernet (RJ45 connectors) is common for networked communication, while RS232 and RS485 are used for serial communication, often in older or simpler systems.
- Integration Considerations: When integrating PLCs with various systems (SCADA, IoT platforms, etc.), it’s important to consider both the protocol compatibility and the physical connection capabilities.
- Security and Reliability: In industrial environments, the reliability of communication and the security of data are paramount. Ensure that the communication method chosen aligns with these requirements.
This table offers a basic overview and can vary based on specific system configurations, PLC models, and industrial setups. Always consult with a systems engineer or industrial network specialist when designing or modifying your industrial communication network.
“Kepware” is widely known for its product KEPServerEX, a software application that provides a robust and reliable way to connect different industrial devices and applications. KEPServerEX supports a wide range of both input and output protocols used in industrial automation and IoT. Here’s an overview of some of the commonly supported protocols:
Input Protocols (Communication with Devices)
- Modbus: Both Modbus TCP (Ethernet) and Modbus RTU (Serial).
- OPC: Including OPC DA (Data Access) and OPC UA (Unified Architecture).
- Siemens: Including S7 MPI, S7 PPI, S7 Ethernet.
- Allen-Bradley/Rockwell Automation: Including EtherNet/IP, DF1, and ControlLogix.
- Mitsubishi: Including MC Protocol and Melsec Serial.
- GE: Including SRTP and GE Fanuc CCM.
- BACnet: Commonly used in building automation systems.
- SNMP: For network device monitoring.
- DNP3: Used in utilities and SCADA systems.
- Beckhoff TwinCAT: For Beckhoff automation devices.
Output Protocols (Integration with Other Systems)
- OPC UA: For server functionality, allowing integration with modern OPC UA clients.
- OPC DA: For legacy OPC systems.
- MQTT: Increasingly used for IoT applications.
- ODBC: For integration with databases.
- ThingWorx: PTC’s IoT platform, for IoT applications.
- REST API: For custom integrations with web-based systems and applications.
Additional Features
- Device Drivers: KEPServerEX includes a wide array of device drivers, allowing it to connect to a vast range of industrial hardware.
- Data Aggregation: It can aggregate data from various sources and make it available in a standardized format to higher-level applications.
- Redundancy: Offers options for redundant connections to ensure high availability.
- Security: Includes features for secure communications, such as SSL/TLS for OPC UA.
- Scalability: Can be scaled to meet the needs of large industrial environments.
Use Cases
- Manufacturing: Connecting PLCs and other industrial devices to MES and ERP systems.
- Energy: Integrating renewable energy sources with utility control systems.
- Building Automation: Integrating building systems (HVAC, lighting) with centralized control systems.
- Oil and Gas: Connecting field devices to SCADA and control systems for monitoring and control.
Remember, the specific protocols supported can depend on the version of KEPServerEX you are using and the licensing options you have chosen. Always refer to the latest documentation from Kepware for the most accurate and comprehensive list of supported protocols.
