Medrad ProVis Mark V, Руководство по обслуживанию

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Mark V ProVis Injection System
9 - 2
Controller Card
Through a cable, the Control Panel connects to J22 on the rear con-
nector panel, which provides power to the Control Panel, and allows
two-way serial communication between devices.
The communication protocol is RS-232C, with automatic retries and
error checking. During power-up or recovery from System Monitor
faults, the Controller Card and console try to establish error-free com-
munications. If communication errors occur, an error message will be
displayed on the Sentinel.
The microprocessor, memory chips, interface logic, and power supply
are contained on the Controller Card, and described in detail in this
section.
The Controller Card consists of two major sections:
Digital Logic
Power Converter
Digital Logic The digital logic portion on the Controller Card is comprised of the
microprocessor, memory chips, and interface logic.
CPU The CPU (U13) is supported by 64 Kbytes of EPROM / PROM (pro-
gram memory), and 8 Kbytes of RAM. The processor interfaces with
the remaining logic through an 8-bit data bus, 16-bit address bus, and
5-line control bus.
Clock Crystal Y2 (8.0 MHz), with U8 and U6, generates a clock signal of 4
MHz for the CPU and associated peripherals. UART U10 is supplied
with a 3.6864 mHz (Y1) crystal oscillator clock.
Memory Processor memory is comprised of three chips: U15 and U16, each
providing 16 Kbytes of program memory (EPROM); U14, providing 8
Kbytes of data memory (RAM).
Memory / I/O Decoder Memory / I/O decoder U12 receives the CPU address, data and con-
trol busses, and decodes and activates the peripheral chips.
PIO Programmable Input/Output chip U2 provides the processor with 17 I/
O lines: Twelve of these lines (A0-A3, B0-B7) scan the panel key-
board; One output line (A7) drives buzzer BZ1; One line (A6) is the
remote handswitch input; One output, A5, drives the Arm light of an
armed indicating handswitch.
For additional information on Keypad inputs, see the I/O Card
Description on page 6 - 1.