Overall Machine Control - Ricoh FT4220 Service Training Manual

4. OVERALL MACHINE CONTROL

Copier Main Board (PCB1)
RXD
TXD
The DF CPU monitors the input signals from the sensors and switches, and
energizes the solenoids and the indicator LEDs directly. The belt drive motor
and the inverter motor are controlled by the DF CPU through their respective
driver ICs. The exchanged signals are shown in the tables on the next page.
FT4220/4222
DF Main Board (PCB1)
TXD
CPU
RXD
ROM
3-4
Sensors
Switches
Solenoids
Indicators
Driver
Belt Drive
IC
Motor
Feed-out
Driver
IC Motor
STM