Period of time between timer events
TimerPeriod specifies the time, in seconds,
that must pass before the callback function specified for
called. Time is measured relative to when the serial port object is
connected to the device with
Some timer events might not be processed if your system is significantly
slowed or if the
TimerPeriod value is too small.
The default value is 1 second. The minimum value is 0.01 second.