Maple Systems cMT units can function as both an HMI and a PLC by running a CODESYS runtime alongside the EasyBuilder Pro interface. This allows a single device to handle visualization, control logic, and system communication in one platform.
The units are designed with a multi-core architecture that separates responsibilities between the interface and control execution. EasyBuilder Pro runs the HMI screens, while CODESYS runs the PLC logic using IEC 61131-3 programming languages such as Ladder Logic or Structured Text. This separation ensures that graphical performance does not interfere with real-time control.
How it works
- EasyBuilder Pro handles the HMI interface and user interaction
- CODESYS executes control logic on the same device
- Both operate simultaneously on separate processing resources
With this setup, the cMT acts as a soft PLC, eliminating the need for a separate controller in many applications.
System architecture
- The cMT unit runs both the HMI project and PLC logic
- Remote I/O modules handle physical inputs and outputs (sensors, actuators)
- Communication between the cMT and I/O occurs over industrial networks such as:
- Modbus TCP
- CANopen
- EtherCAT
Remote I/O modules are installed near field devices and send data to the cMT, where the CODESYS runtime processes inputs and determines outputs.
How data flows
- Remote I/O provides input data to the cMT
- CODESYS processes control logic
- Outputs are sent back to the I/O modules
- The HMI reads and writes data through PLC variables managed by CODESYS
From the HMI perspective, all data—whether from local logic or remote I/O—is accessed through PLC variables rather than directly from hardware.
Key advantages
- Combines PLC and HMI functionality into a single device
- Reduces wiring and hardware requirements
- Simplifies system design and deployment
- Scales easily by adding remote I/O modules
- Maintains clear separation between control and visualization
In practice, a cMT unit with CODESYS serves as the central controller, operator interface, and communication hub. It provides a compact and integrated solution for modern automation systems while supporting distributed I/O and flexible system expansion.