Define the function keys of the user-defined keys
0: The multifunction key define 1 as the add function key.
In the monitor menu, the add function key proceed the add modify of the keyboard
setting frequency through F0.01 .
In the parameter selection menu, The add function keys adjust the parameter
selection
In the parameter modify menu, the add function keys adjust the parameter value.
The multifunction key define 2 as the subtract function key.
Under the monitor menu , the subtract function keys proceed the subtract modify of
the keyboard setting frequency through F0.01 .