4-12
Troubleshooting
Figure 4-5
Digital circuitry block diagram
A/D
Control/Data
Voltage Source
Control
ROM
U15, U16
RAM
U12, U14
Reset
E PROM
U17
2
A/D Interface
U9, U25
Microprocessor
U3
Serial
Interface
U4
GPIB
U6, U13
U20
RS-232
Interface
IEEE-488
Interface
To Display
Board Controller
16.78MHz
Trigger
U23
Trigger
Digital I/O
U7
Digital
I/O
Display board circuit theory
Display board components are shown in the digital circuitry block diagram in Figure 4-5.
U902 is the display microcontroller that controls the VFD (vacuum fluorescent display)
and interprets key data. The microcontroller has four peripheral I/O ports that are used for
the various control and read functions.
Display data is serially transmitted to the microcontroller from the digital board via the
TXB line to the microcontroller PD0 terminal. In a similar manner, key data is serially
Summary of Contents for SourceMeter 2425
Page 3: ...TAIWAN 1FL 85 Po Ai Street Hsinchu Taiwan R O C 886 3 572 9077 Fax 886 3 572 9031...
Page 15: ......
Page 16: ...1 PerformanceVerification...
Page 35: ...1 20 Performance Verification Model 2425 Service Manual...
Page 36: ...2 Calibration...
Page 62: ...3 RoutineMaintenance...
Page 65: ...3 4 Routine Maintenance Model 2425 Service Manual...
Page 66: ...4 Troubleshooting...
Page 84: ...5 Disassembly...
Page 92: ...6 ReplacementParts...
Page 113: ...6 22 Replacement Parts Model 2425 Service Manual...
Page 114: ...A Specifications...
Page 116: ...B CommandReference...
Page 128: ...C CalibrationPrograms...
Page 139: ......
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