This is yet another tango test device.

*** DEVICE PROPERTIES (use jive) ****

'mthreaded_impl' : if set to 1 (i.e. true) the device use a thread to generate attribute 
		   values (avoiding data generation overhead on attributre reading). 
		   Defaults to true.

'sleep_period'   : time between two thread excecutions in ms. Default is 250.