Teledyne AX300-I manual Watchdog, Error Codes

Portable Oxygen Analyzer Service Manual

Note: In the event that none of these procedures produce desired results, remove the batteries and return the unit to Teledyne for repair.

3.8 Watchdog

The AX300-I is equipped with a watchdog circuit that continuously analyzers the electronics for proper operation. If the watchdog detects a failure, one of the following codes will appear on the LCD.

The error codes can appear on the LCD when batteries are first installed, during normal operation or if the unit is subjected to extreme shock. In some cases an additional digit is used in the error code to supply additional information. For example, the error code 6 and 7 are followed by another digit listed as (N) in Table 3.3. The error code 65 would indicate that a key is stuck and this key is the Silence key.

In addition to supplying visual error codes, the audio device will beep a number of times to indicate the general error in case the display is not functional.

Note: To reset the watchdog error code. Remove one battery for 5 seconds and replace. If the error persists contact your locale representative or Teledyne for assistance.

Table 3-3 Error Codes

Error Code	Audio Beeps	Error
Indeterminate	2	The watchdog timer has timed out indicating
		a serious software error
30	3	Analog output is different from the expected
		value. May indicate a shorted or over-loaded
		analog output or a failure of the analog to
		digital converter or digital to analog
		converter circuit.
50	5	The ADC circuit failed during POST.

Teledyne Analytical Instruments 39