Ethernet/IP to CC-Link Gateway: Unify Industrial Networks
In many factories, a common challenge arises when legacy CC-Link networks, which connect core controllers and sensors, need to communicate with newer Ethernet/IP devices such as advanced HMIs, PLCs, or smart instruments. These two protocols often operate as isolated islands, preventing seamless data flow and reducing overall system efficiency. An Ethernet/IP to CC-Link gateway solves this by acting as a powerful translator, enabling dual-network integration without replacing existing infrastructure.
This article explores the technology behind such gateways, their dual master-slave architecture, typical use cases, and key factors to consider when selecting a device for your industrial automation system.
How the Dual Master-Slave Architecture Works
A protocol conversion gateway typically implements a dual master-slave design. On the CC-Link side, it functions as a CC-Link master station, actively polling all connected slave devices such as PLCs, remote I/O modules, and variable frequency drives. It collects real-time operational data from these devices. On the Ethernet/IP side, the gateway acts as an Ethernet/IP adapter (slave), making the collected data available to an Ethernet/IP scanner (master), such as a Rockwell ControlLogix PLC or a SCADA system. This bidirectional data exchange happens in real time, often with configurable mapping between the two networks’ data tables.
The gateway manages the entire CC-Link network cycle, handling token passing and I/O refresh, while simultaneously maintaining an Ethernet/IP I/O connection. This ensures that data from legacy CC-Link devices appears as native Ethernet/IP tags, and commands from the Ethernet/IP side are transparently written to CC-Link registers.
| Feature | CC-Link Side | Ethernet/IP Side |
|---|---|---|
| Role | Master station | Adapter (slave) |
| Communication | Polls slaves, cyclic I/O | I/O connection to scanner |
| Data Mapping | RX/RY, RWr/RWw | Assembly instances |
| Typical Devices | Mitsubishi PLCs, I/O blocks, drives | Rockwell PLCs, HMIs, vision systems |
Real-World Application Scenarios
The gateway is particularly valuable in mixed-vendor environments. Consider a manufacturing line where legacy CC-Link based conveyor controls must integrate with a new Ethernet/IP vision inspection system. The gateway maps the vision system’s pass/fail results into CC-Link bit registers, allowing the existing PLC to reject defective parts without any hardware changes.
In smart warehouse logistics, automated guided vehicles (AGVs) often communicate via Ethernet/IP, while storage rack controllers may use CC-Link. The gateway enables the AGV dispatch system to directly command rack movements, synchronizing material handling and improving throughput. Another common use is connecting Ethernet/IP HMIs to CC-Link PLCs for data visualization and operator control.
These gateways also support remote monitoring: an Ethernet/IP SCADA system can collect production counts, alarm states, and energy data from multiple CC-Link segments, providing a unified view of plant operations.
Key Selection Criteria for an Ethernet/IP to CC-Link Gateway
When choosing a gateway, consider the following technical aspects:
- CC-Link version support: Ensure compatibility with CC-Link Ver.1.10 or Ver.2.00, and the maximum number of occupied stations (e.g., 1 to 4 stations).
- Data capacity: Check the maximum I/O points (e.g., 128 words per direction) and whether it supports both bit and word data.
- Ethernet/IP features: Look for support of implicit (I/O) and explicit messaging, and the number of simultaneous connections.
- Configuration ease: Many gateways offer web-based configuration or dedicated software for mapping data without programming.
- Diagnostics: LED indicators for network status, error logs, and diagnostic web pages simplify troubleshooting.
- Environmental ratings: Industrial temperature range (-20°C to 60°C) and DIN rail mounting are typical.
Typical Configuration Steps
Setting up a gateway usually involves these steps:
- Connect the gateway to the CC-Link network and configure its station number and baud rate via DIP switches or software.
- Connect the Ethernet/IP port to the network and assign an IP address.
- Use the configuration tool to map CC-Link RX/RY and RWr/RWw areas to Ethernet/IP assembly instances.
- In the Ethernet/IP scanner (e.g., RSLogix 5000), add the gateway as a generic Ethernet module with the appropriate assembly sizes.
- Verify data exchange by monitoring live values on both networks.
Pro Tip: For large systems, consider gateways that support multiple CC-Link master instances or have built-in Ethernet switch ports to simplify cabling. Always verify that the gateway firmware is up to date to ensure compatibility with the latest PLC models.
Conclusion
An Ethernet/IP to CC-Link gateway is a critical enabler for Industry 4.0, bridging the gap between legacy fieldbus networks and modern Ethernet-based systems. By implementing a dual master-slave architecture, it allows seamless, real-time data exchange without costly rip-and-replace upgrades. Whether you’re integrating vision systems, AGVs, or SCADA, this protocol converter simplifies multi-vendor automation and extends the life of existing assets.
When selecting a gateway, focus on data capacity, ease of configuration, and robust diagnostics to ensure reliable operation in demanding industrial environments.
