Common parameters and specifications of PLC modules may include:

1. Number of Digital Inputs/Outputs: Specifies the number of digital input and output channels the module can handle.
2. Analog Inputs/Outputs: Indicates the number of analog input and output channels that can be used for precise control and monitoring.
3. Communication Interfaces: Specifies the type of communication interfaces supported, such as Ethernet, Profibus, Modbus, etc.
4. Processing Speed: Indicates the speed at which the module can process input data and send output signals.
5. Memory Capacity: Specifies the amount of memory available for storing programs and data.
6. Operating Temperature Range: Indicates the range of temperatures within which the module can operate effectively.
7. Power Supply Requirements: Specifies the voltage and current requirements for powering the module.
8. Dimensions and Mounting: Provides information about the physical dimensions of the module and how it can be mounted in the control system.