How To Achieve Cross-brand Communication between PLC & Touch Screen

To achieve cross-brand PLC and HMI communication, use a common industrial protocol.

The following examples use Siemens (HMI) and Schneider (PLC) to illustrate this point.

Are there any mandatory requirements for using Schneider PLCs with Siemens touch panels? For example, regarding communication protocols and interfaces. Which specific models from these two brands are compatible for use together?

Connecting a Schneider PLC with a Siemens touch panel is not a plug-and-play process. However, cross-brand integration is achievable provided certain conditions are met. This typically requires the Siemens HMI to support the communication protocols used by the Schneider PLC. Below are the key requirements and common compatible setups.

1. Core Mandatory Requirements

1.1 Communication Protocol Compatibility
The Siemens HMI must support the communication protocols used by the Schneider PLC, such as:

• Modbus TCP/IP (for Ethernet communication)

• Modbus RTU (for serial communication)

• EtherNet/IP (supported by some models)

• OPC UA/DA (via an intermediary server)

1.2 Interface Compatibility

• Ethernet Interface: The most common method. Ensure both devices have compatible port types (RJ45) and matching speeds.

• Serial Interface (RS232/RS485): Ensure the physical interfaces match and parameters like baud rate and data bits are set identically.

1.3 Hardware & Software Configuration

• The Siemens HMI must have the corresponding protocol driver or option installed (e.g., Modbus TCP driver).

• The Schneider PLC must have the relevant communication service enabled (e.g., Modbus Slave functionality).

2. Recommended Compatible Model Combinations

Scenario 1: Based on Modbus TCP/IP Communication

• Schneider PLC:

• M Series (M340, M580)

• L Series (LMC058, LMC078)

• Key Configuration: Enable the "Modbus TCP Server" function on the PLC.

• Siemens HMI:

• Basic Panels: e.g., KTP700 Basic, TP1200 Basic

• Comfort Panels: e.g., TP1500 Comfort

• WinCC Advanced (PC-based HMI)

• Key Configuration: Install the Modbus TCP driver and configure the PLC's IP address and register addresses in the HMI project.

Scenario 2: Based on Modbus RTU Communication

• Schneider PLC:

• Twido Series (with RS485 interface)

• M218 Series (requires configuring a serial module)

• Siemens HMI:

• Models with COM ports (e.g., TP700 Comfort)

• Key Configuration: Use the RS485 interface and configure the slave address and register mapping.

Scenario 3: Bridging via an OPC Server

If the HMI does not support the protocol directly, an OPC Server (e.g., KEPServerEX) can act as a bridge:

1. Connect the Schneider PLC to the OPC Server.

2. The Siemens HMI accesses the data via an OPC DA/UA client driver.

3. Configuration Steps Example (Modbus TCP)

1. Schneider PLC Side (using M340 as an example):

• Enable the "Modbus TCP" function block in Unity Pro.

• Define shared registers (e.g., %MW0 to %MW100).

• Set a fixed IP address for the PLC.

2. Siemens HMI Side (using TP1500 Comfort as an example):

• Create an HMI project in TIA Portal.

• Add a "Modbus TCP" connection and enter the PLC's IP address (default port 502).

• Enter variable addresses in Modbus format (e.g., 40001 corresponds to %MW0).

4. Important Considerations

• Manual Address Mapping Required: Schneider register addresses (e.g., %MW0) must be converted to Modbus addresses (e.g., 40001).

• Potential Performance Limitations: Response times for cross-brand communication may be slower compared to native brand solutions.

• Functional Limitations: Advanced features (e.g., alarm archiving, recipes) may require additional configuration or might be limited.

5. Alternative Suggestions

If communication setup proves too complex, consider:

1. Using Schneider HMIs (e.g., Magelis series) for seamless integration with their PLCs.

2. Opting for third-party HMIs (e.g., Proface, Weintek), which often offer more flexible multi-protocol support.

Conclusion
With the appropriate selection of protocols and models, Schneider PLCs and Siemens HMIs can work together effectively. 

Similarly, this solution is also applicable to other brands such as Mitsubishi, Inovance, and Weintek.

If you need packaging machine equipment, or if you are experiencing communication problems between the PLC and HMI of your packaging machine equipment, please feel free to discuss it with me.

More machine detail，Please contact me.

Hunan Grand Packing Machinery

Ava Duan

Mobile/Wechat/Whatsapp: 0086-13706885851

Email: sales@grand-packing.com