Motherboard Pcb - Agilent Technologies VS Series Operation Manual

The CPU circuitry resides on a stand-alone PC104 PCB comprised of six sections:
MCU and memory (SRAM, FLASH and EEPROM) section
Real Time Clock/Calendar section with the battery and super capacitor backup with
4-pin battery connector (JXBT) and IRQ1 jumper
RS-232 section with 9-pin connector (J2); pin No. 10 is removed
BDM section with 10-pin connector (J1)
Time processor section with 34-pin connector (J4); not used in VS leak detector.
Parallel interface section with two 64-pin, 0.1x0.1, PC-104 bus type I/O connectors
(J3)
A.2.2 Motherboard PCB
The Motherboard PCB (Agilent P/N R2101301) functions as liaison between the CPU PCB
and all other hardware section under full software control provided by CPU PCB.
The Motherboard PCB circuitry provides:
Parallel interface (Data, Address and Control) communication between a CPU and
an Ion Source PCBs
UART/RS-232 non–isolated parallel-to-serial and serial-to-parallel interface for the
leak detector peripherals such as:
RS-232 isolated serial communication between the CPU PCB and a rear panel serial
diagnostic port
Isolated leak rate analog output (0-10 VDC)
Parallel-to-serial and serial-to-parallel communication between the Pre-amp ADC
PCB and CPU PCB
Test Port Thermocouple (TP TC) power supply and TP pressure voltage-to-frequency
signal conversion
Isolated calibrated leak temperature frequency signal conversion
CLPD control signals generation, data-to-frequency and frequency-to-data
conversion
+24 VDC to a +5 VDC DC-DC conversion for the 5V-logic supply and clock/
memory battery power back up.
A-4
VS Series Component Leak Detector
Front Panel PCB
Turbo Pump Controller PCB
Discrete I/O PCB