CMC Remote I/O Features:
1. CMC Remote I/O (Profinet, Profibus, EtherCat, CANOPEN, CCLINK, Devicenet) provides high-speed input/output IO without requiring couplers.
2. Digital inputs: 16Ch (NPN/PNP), Digital outputs: 12Ch (PNP), with optocoupler isolation.
3. Communication circuits use integrated ICs or high-speed optocoupler isolation; Ethernet uses transformer isolation.
4. Power input: 24VDC (-15%/+20%), with independent digital power supply and module communication power supply.
5. Installation method: DIN rail (TS35).
6. Input/output terminal blocks are pluggable.
    

    

CMC Profinet Remote I/O and Expansion

CMC Profinet Remote I/O Control Solution

By understanding the process flow and control requirements of water treatment plants, equipment such as feed pumps (pressure pumps, backwash pumps, return pumps, backwash fans, electric valves, etc.) must support upper-level computer control, on-site pump control, and real-time monitoring of operational data. In the past, frequency control cabinets were connected to the PLC via cables — often requiring multi-core cables (such as start/run signals, fault signals, frequency setpoints, frequency feedback, current feedback, etc.). Then from the pump site to the PLC cabinet, another multi-core cable was needed (for electric valve control, pressure display, vibration display, temperature display, etc.). With CMC's Profinet remote I/O modules, a control box with a touch screen and remote I/O can be installed near each pump, connecting to the PLC via a single communication cable. A remote module inside the inverter cabinet is all that’s needed to achieve simultaneous control from the control room, inverter cabinet room, and on-site location.

As shown in the above figure: Each pump is equipped with a nearby control box featuring a touch screen and remote I/O, capable of controlling the pump’s operating frequency and displaying its status, operating current, frequency, motor temperature, vibration, and inlet/discharge pressure.

Each inverter only requires one CMC Profinet remote I/O module to control the inverter’s start/stop, frequency setting, collect run/fault signals for automatic control of electric valves, and monitor inverter operating current and frequency.
When the distance between the control room and the pump site or inverter cabinet exceeds 100 meters, CMC's Profinet remote I/O modules can also be used with network transceivers for long-distance fiber optic transmission. As shown in the figure below:

Additionally, in water treatment plants, many monitoring data points need to be collected, such as pH value, turbidity, residual chlorine, water level, flow rate, and current/voltage/power within high-voltage cabinets. These can be transmitted via bus using CMC gateways.

In high-voltage cabinets, a multifunctional power meter with Modbus 485 communication is typically designed into the system. However, using Modbus 485 may result in slow transmission speeds and susceptibility to interference. CMC's Profinet gateway effectively solves these issues.

    
In summary, using CMC's Profinet remote I/O and gateway offers the following advantages over traditional control methods:
1. Only one communication cable is required between the control room, field devices, and inverter cabinets, significantly reducing control cable usage.
2. The PLC cabinet is divided into several small control boxes, making wiring easier and less error-prone.
3. The system is modularized into multiple control boxes, making troubleshooting more efficient when faults occur.
4. Bus-based transmission enhances anti-interference capabilities.
5. When new devices need to be added, simply install an additional small control box, making system expansion convenient and simple.