
118
Teledyne API – Model T400 O
3
Analyzer
083730400A DCN8130
5.7.3
T
HE
D
IAGNOSTIC
S
IGNAL
I/O
F
UNCTION
The Utilities>Diagnostics menu provides a view of the digital and analog I/O signals in
the analyzer. These signals, combined with a thorough understanding of the instrument’s
Theory of Operation (found in Section 6), are useful for troubleshooting in three ways:
•
The technician can view the raw, unprocessed signal level of the analyzer’s critical
inputs and outputs.
•
Many of the components and functions that are normally under algorithmic control of
the CPU can be manually exercised.
•
The technician can directly control the signal level Analog and Digital Output signals.
This allows the technician to observe systematically the effect of directly controlling
these signals on the operation of the analyzer. Use the Utilities>Diagnostics menu to
view the raw voltage of an input signal or the Setup menu to control the state of an output
voltage or control signal.
5.7.4 S
TATUS
LED
S
Several color-coded light-emitting diodes (LEDs) are located inside the instrument to
assist in determining if the analyzer’s CPU, I
2
C bus and relay board are functioning
properly.
5.7.4.1 CPU STATUS INDICATOR
DS5, a red LED that is located on the upper portion of the motherboard, just to the right
of the CPU board, flashes when the CPU is running the main program loop. After power-
up, approximately 30 to 60 seconds, DS5 should flash on and off. If the front panel
display is working, but DS5 does not flash, then the program files have become
corrupted. If after 30 – 60 seconds neither the DS5 is flashing nor is the front panel
display working, then the CPU is bad and must be replaced.
Motherboard
CPU Status LED
Figure 5-11. CPU Status Indicator
Содержание T400
Страница 2: ......
Страница 101: ...99 Teledyne API Model T400 O3 Analyzer 083730400A DCN8130 This page intentionally left blank ...
Страница 176: ...This page intentionally left blank A 4 083730400A DCN8130 ...
Страница 177: ...Appendix B Wiring Diagram 083730400A DCN8130 ...