Clarus 500 GC - CHAPTER 7 DIAGNOSTICS; INSTRUMENT START UP DIAGNOSTICS; CHROMATOGRAPH MODE DIAGNOSTICS

Clarus GC 500 Service Manual
vii
Signal Name Notation.................................................................................................9-23
Microprocessor ..........................................................................................................9-23
Memory.....................................................................................................................9-24
Main Board Interface..................................................................................................9-24
Input/Output ..............................................................................................................9-24
System Operation.......................................................................................................9-24
Motor Control............................................................................................................9-25
Current Control..........................................................................................................9-25
Carousel Encoder Interface.........................................................................................9-27
Tower Ilnterface PC Board..........................................................................................9-27
Design Specification...................................................................................................9-28
Block Diagram/Overview ...........................................................................................9-29
Microprocessor ..........................................................................................................9-29
Main Board Interface..................................................................................................9-29
Memory.....................................................................................................................9-30
Xilinx Field Programmable Gate Array PWM Control..................................................9-30
Analog Input / Analog to Digital Conversion................................................................9-30
On Board Ambient Pressure Transducer......................................................................9-32
Voltage References.....................................................................................................9-33
Pressure Modules Interface.........................................................................................9-34
Switching Power Supply .............................................................................................9-34
FID Amplifier PC Board.............................................................................................9-35
Polarizing Voltage......................................................................................................9-35
Electrometer ..............................................................................................................9-35
A/D Converter Front End Stages.................................................................................9-36
Analog Signal Output .................................................................................................9-37
Voltage Reference......................................................................................................9-37
Electrometer Balance Adjustment................................................................................9-37
ECD Amplifier PC Board...........................................................................................9-37
Standing Current Feedback Control Loop ....................................................................9-37
Frequency-to- Voltage Converter ................................................................................9-38
A/D Converter Front End Stage...................................................................................9-38
Analog Signal Output .................................................................................................9-39
Voltage Reference......................................................................................................9-40
TCD Amplifier PC Board...........................................................................................9-40
Command Decoding...................................................................................................9-40
Bridge Ground System................................................................................................9-41
Bridge Current Range Select.......................................................................................9-41
Bridge Current Control...............................................................................................9-41
Bridge Output Circuits................................................................................................9-41
Safety Circuits ...........................................................................................................9-41
A/D Converter Front End Stage...................................................................................9-42
Analog Signal Output .................................................................................................9-43
Voltage Reference......................................................................................................9-43
TCD Range Values.....................................................................................................9-44
FPD Amplifier PC Board............................................................................................9-45
High Voltage Section..................................................................................................9-45
Electrometer ..............................................................................................................9-45
A/D Converter Front End Stage...................................................................................9-45
Analog Signal Output .................................................................................................9-46