Datex-Ohmeda Anesthesia Delivery Unit S/5, Technical Reference Manual

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Troubleshooting A-ELEC
Document No. 8502856
D-45
Discharge/recharge cycling test
Run the ADU on batteries until it turns itself off and then let it recharge. Observe that the discharge
current for each pack is about 1A and that the charge current is 450 to 500 mA. Repeat this cycle if
necessary. This will level out the differences in the batteries. This test is recommended when new
batteries are installed.
NOTE: When replacing batteries in ADU all 4 must be replaced at the same time. Batteries supplied
by Datex-Ohmeda should always be used in ADU, because we are testing and selecting the batteries
to each others. ADU problems due to locally purchased batteries we do not take any responsibility
for.
Unexpected reset
In a reset condition, the display shows the message ´System failure - Unexpected Reset, please call
for service´.
If an Unexpected reset occurs the Electronic Ventilator and the Fresh Gas Control units continue to
deliver gas as set, but you will be unable to adjust the ventilator settings. Fresh gas flows and
anesthetic agent settings can be adjusted, but the settings are not displayed on the screen.
How the reset system of the ADU works
When an ADU is started the following happens: As soon as power is applied the watchdog (located at
the Digipower board) activates the reset signal to the CPU. When the +5V line rises above 4,65V an
internal timer in the watchdog keeps the reset active for 200 ms to ensure that the CPU will be
properly reset after power up. When the main SW starts to execute it sends a start command to the A-
EV1. If main SW gets a good response from the A-EV1 it continues with the start-up of the ADU.
However if it receives a message from the A-EV1 saying that it is already running, this is interpreted by
the main SW as an error. Main SW should start the A-EV1, if it is already running this is an indication
that the CPU has done a warm start. This will result in the error messages on the screen and prevent
further operations of the ADU. During normal program execution main SW must do a watchdog kick at
least once every second to prevent it from doing a reset of the CPU.
Display description if a reset occurs
When a reset condition occurs, the ADU displays the following:
1.
The screen blanks out.
2. After approximately 10 seconds, the “Datex-Ohmeda” is shown.
3. After another 20 seconds, the screen will appear as if in a normal start-up.
4. After another 20 seconds, the message “System Failure - Unexpected Reset, Please call for
service” appears in red.
Service recommended actions if a reset occurs
•
Check service error log
•
Check Voltages on diagnostic pages
•
Run HW watchdog test from service page if test fails replace.
−
A. Replace the B-CPU board and repeat the test.
−
B. Replace the Digipower board and repeat the test.
•
On the B-CPU2 board check that the SW cassette is correctly installed and that the insulation is
present.