Some of the main exposition plc cpu modules modules

If there is an alarm relay on the meter, then set the alarm temperature on the instrument, the output relay is directly connected to the digital inputs plc and public clients. If there is no alarm relay on the  input module plc meter (meter is no such general alarm relay), direct access to analog values ​​plc to make their own alarm in the program. And direct access to the analog case plc, and because plc and instrumentation wiring different models differ, analog signal inputs can be 4-20mA, it can be 0 - (5) 10V, can also be thermal resistance and the like, the situation is more, the need for specific models can be. What is the installation of the module depends on the general  programmable logical controllers input and output modules are not installed the driver, but the Mitsubishi motion CPU modules need to install the driver and set up. General PLC run the installer to write a good program it. Not add a module plus a driver, such as AD / DA module, just write in the program on it. Some PLC is not with AI (analog input) and AO (analog output) function, but usually there with an expansion slot, or expansion socket for programmable logic controller  adding analog input and output functions, 32DI (32 个input module), 32DO (32 output ports module), if the PLC itself comes with input and output ports is not enough, you can add these modules to perform the functions specified pull.