SCXI-1300 each circuit is very important, the requirements must be quickly and accurately determine the point of failure when the first scheme is better; in general the third scheme is better, due to the fault classification alarm display, you can directly determine the nature of the fault, know what kind of impact on the equipment or industrial process, you can immediately take appropriate measures to deal with it, and at the same time combined with other phenomena, factors, another set of alarm conditions from this kind of classification of specific fault points. At the same time, in combination with other phenomena, factors, another set of alarm conditions or several sets of alarms will be specific points of failure from such a division.

SCXI-1300 have LED indicators can help check whether the fault is caused by external devices. Whether in the simulation debugging or practical applications, if a system circuit can not act in accordance with the requirements, you should first check whether the PLC input switch electrical contact point is reliable (generally by viewing the input LED indicator or direct measurement of the input), if the input signal fails to transfer to the PLC, you should go to check the input corresponding to the external circuit;