This class inherits from RevPiBaseIO and expands ist range of functions.
In addition to bytewise access to the value, this value can also be directly returned or set as a value defined by struct(). The struct formatting is passed by reg_inp(), reg_out() of the class RevPiGateway.
The following attributes are available / changed:
str() object that contains the struct() formatting for pack() and unpack()
Returns the value as a value defined by struct()