How to define a port signal variable in a M-file

How to define a port signal variable in a M-file just use one sentence eg. I want to set its DataTyte ,InitialValue,Min,Max and so on. Maybe I can do it as follows: canFaultFlag = mpt.Signal; canFaultFlag.DataType = 'boolean'; canFaultFlag.InitialValue = '0'; ... But how can I finish it in one sentence and which function I can use to create a signal varialbe?