 The Contact Handling System (CHS) is a software application intended to provide more information to call handlers when taking emergency calls.CHS differs from the older CAD system and from systems used by other emergency services worldwide in that far more information can be input into the system by the CAD Operator and the information can be retrieved and sorted more easily.However, it has proven unpopular thus far with CAD Operators and Police Officers; operators consider it unnecessarily complicated to use, and police find CHS-derived information difficult to interpret, particularly via MDT terminal.