R.V.R. Elettronica PTX30 UHT/S3, User Manual

Page: 37 / 122

PTX30 UHT /S3
31 / 36 User Manual Rev. 5.0 - 10/12/2001
9.8 CPU
The CPU board is installed on the front panel in the central position, and includes
the microcontroller (68HC11) and the related components, a led display and the
buttons for the frequency setting.
This circuit translates the number corresponding to the selected frequency into a
binary code that is sent to the PLL programmable dividers to allow the VCO to lock
on the right frequency.
An RS232 port, permits the remote control of some parameters of the exciter and
the programming of the CPU; these features are available for maintenance
personnel.
The last selected frequency is stored in a non-volatile part of the memory, so that
at power up that frequency will be used.