Input sampling stage

In the input sampling stage, PLC scan mode sequentially reads all input states and data, and store them in the I / O image area corresponding the unit. After the end of the input plc analog input module sample, into the user program execution and output refresh period. In both stages, and even if the input data changes state, status, and data I / O of the image area of the corresponding cell is not changed. Therefore, if the input is a pulse signal, the width of the pulse signal

plc analog input output io module

must be greater than one scanning cycle, in order to ensure that in any case, the input can be read.