The software is HOLLiAS_MACS_V6.5.3,the hardware is K Master+K module.The SOE of HollySys DCS is to adjust the time to the minimum control station of double-net,but during the normal operation of the unit,some SOE modules have time-out alarm,on the premise that there is no other factory experience can be used for reference,the operators through the master-slave history station switching,restart,loading,effective,the controller switching,K-BUS02 module switching,switch power failure in different areas of the switch restart,and so on a large number of field tests,and finally found the SOE module timeout alarm factors.