Xerox WorkCentre XK50cx, Service Manual

Page: 52 / 109

4-25
Circuit
4-3 OPE PBA
4-3-1. SUMMARY
OPE Board is separated functionally from the main
board and operated by the micom (HT48R50) in the
board. OPE and the main use UART (universal asyn-
chronous receiver / transmitter) channel to exchange
information. OPE reset can be controlled by the main.
OPE micom controls key-scanning and LCD and LED
display.
If there occurs an event in OPE (such as key touch
and sensor level change), it sends specific codes to
the main to respond to the situation and the main
analyzes these codes and operates the system. For
example, if the main is to display mes-sages in OPE,
the main transmits data through UART line to OPE
according to the designated format and OPE displays
this on LCD, LED. OPE’s sensing is also transmitted
to the main through UART line and then the main
drives necessary operation.
4-3-2.
OPE PBA consists of U1 (MICON, HT48R50), LCD,
key matrix, LED indicators.
Refer to OPE Schematic Diagram and Wiring
Diagram sections of this manual.
• Signals from the key matrix are delivered to U1X/Y
input pin group (P1-x).
• U1 pin 48 (TX DATA) is the UART code sent to
MAIN PBA.
• Display from the controller is received at U1 PIN 47.
• LCD drive signals are sent from U1 P2-x pin group,
P3-4~P3-6 pins.
• Machine status LED drive signals are sent from U1
P0-x pin group.
Fig.4-3-1 OPE Block Diagram