The P0973LN is a programmable logic controller (PLC) from FOXBORO. In industrial automation and control systems, PLCS play a vital role in controlling various equipment and processes. The P0973LN module is specifically used to realize the progressive scanning and execution of the control logic, which completes the control task by reading the input state, executing the program operation and updating the output state.
The main way of operation of the module is to first check the state of each point switch or sensor connected to the input element, and write its state to the corresponding location in memory. Then, the ladder graph program is fetched into the CPU line by line for computation. The calculation result of the output coil will be stored in the corresponding position in memory, but it will not be reflected to the output end. Finally, the output status is updated to the PLC output contact, and the input status check step is repeated to form a cycle.
