zenon logic

zenon logic

hi,
Im working with a project, the problem is error occur 16bit input is high(ie all bits are high or it is 65535).so this will enable all alarm . i need to avoid such situation.
 i need to identify this 65535 input signal and disable 
how to find all bits of a 16bit are in high(or value is 65535)??
When there is server failure ,then the value of signal received is 65535 and it will effect the SCADA performance.
please help to find a logic to get read of this situation.