Technalogix TAU-100, Руководство пользователя

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VI-6
Microcontroller Components
The heart of the monitor and control system found in Series II-H PCBs is microcontroller U14. This
microcontroller analyzes all RF power levels and voltages to ensure that all operating parameters
are within their predetermined safe operating levels. If a fault is found, appropriate action is taken
to help protect the system from damage, which may include turning the RF carriers off. A full
description of all faults and their respective actions is found later in this section.
The power supply for the microcontroller is monitored closely via supervisor U13. Should the +5Vdc
supply drop below +4.5Vdc, a microcontroller reset is generated to ensure there are no brown out
conditions that may latch the microcontroller up to an unknown state. The front panel Reset
momentary switch is also tied to this line after optoisolation. The microcontroller is run off of a
4.000MHz clock source, generated by ceramic resonator CR1. If the software is running, LED D12
will be lit. Finally, U15 stores all characters for the LCD to minimize the overhead required for the
microcontroller, and also stores the current state of the power ON/OFF of the system. This is to
ensure that, in the event of a power outage, the system returns to the exact state is was before
power was interrupted.