Hollysys LK207 series LK programmable logic controller.

CPU MODULES 

Communication CPU I/O Special Function I/O I/O Terminal Block 

 • This is the main controller of the whole control system. It is responsible for execution of the programmable logic, all data communications with the modules, the HMI, and the operator stations in operation level. 

 • Communications with the local modules are done via internal data bus supporting at normal or high speed baud rate. 

 • Communications with the expansion I/O modules are done via the PROFIBUS-DP fieldbus. 

 • Communications with the operator level are done via Industrial Ethernet. 

 • At the front panel of the CPU module, you will find the LED status indicator, operating mode switches, rotary switches for addressing, SD memory card and backup battery compartment.

As the core of the control system, CPU module undertakes the execution of programmable logic and data communication tasks with various modules and operator stations. The following is a detailed description of its functions:

Communication function:

The CPU module is responsible for the communication with the local module, which is realized through the internal data bus supporting normal or high-speed baud rate, ensuring the efficiency and stability of data transmission.

For the extended I/O module, communication is completed through PROFIBUS-DP field bus, which can effectively connect distributed I/O devices and expand the control range of the system.

The communication with the operator level is carried out through industrial Ethernet, which provides the operator with the ability to monitor and control the system in real time.

Control and interface:

As the main controller of the whole control system, CPU module not only executes programmable logic, but also manages all data communication to ensure the coordination of all parts of the system.

I/O interfaces play a key role in CPU module. They are the bridge for data exchange between CPU and external devices, and are responsible for data format conversion, speed matching and other tasks.

Condition monitoring and operation:

The front panel of CPU module is equipped with LED status indicators, which can display the working status of the module in real time, such as operation and errors, and provide intuitive information for maintenance and troubleshooting.

The operation mode switch and addressing rotary switch allow users to adjust the operation mode and address setting of the module according to actual needs, which enhances the flexibility and configurability of the system.

Data storage and backup:

SD memory card slot provides additional data storage capacity for CPU module, which can be used to store important information such as programs, configuration information or log data.

The spare battery box ensures that key data and settings will not be lost when the main power supply fails, thus ensuring the continuity and reliability of the system.

To sum up, CPU module not only performs well in communication, but also provides comprehensive functions in control, monitoring, storage and backup, making it an indispensable core component in the control system.