Teledyne M300EM User Manual

Page of 398
Teledyne API – Technical Manual - Model 300E Family CO Analyzers 
Troubleshooting & Repair 
 
273
 
13.1.3. DIAG  SIGNAL I/O:  USING THE DIAGNOSTIC SIGNAL I/O 
FUNCTION 
The signal I/O diagnostic mode allows access to the digital and analog I/O in the analyzer.  Some of the digital 
signals can be controlled through the keyboard.  These signals, combined with a thorough understanding of the 
instruments Theory of Operation (found in Section Error! Reference source not found.), 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.  The following flowchart shows an example of how to use the Signal I/O menu to view 
the raw voltage of an input signal or to control the state of an output voltage or control signal.   
 
 
Figure 13-2: 
Example of Signal I/O Function 
NOTE 
Any I/O signals changed while in the signal I/O menu will remain in effect ONLY until signal I/O menu is 
exited.  The Analyzer regains control of these signals upon exit.   
04288D DCN5752