There is a function that is part of AdvancedHMI to help with this:
MfgControl.AdvancedHMI.Drivers.Common.CalculationsAndConversions.WordsToString
Here is an example of how to use it:
Dim v() As String = ModbusTCPCom1.Read("40001", 10)
Dim MyString as String = MfgControl.AdvancedHMI.Drivers.Common.CalculationsAndConversions.WordsToString(v)