Calibration Errors; Auto-Calibration; Details On Tc Serial Command - DeVilbiss IntelliPAP DV54 Service Manual

7.
B. CALIBRATION ERRORS
Code
E95
Calibrate Motor Stop Error. The blower did not
stop during device calibration. This error only oc-
curs during the calibration procedure.
E96
Calibrate Flow Balance Error. The fl ow balance
digital potentiometer did not adjust during device
calibration. This error only occurs during the cali-
bration procedure.
E97
Calibrate Flow Gain Error. The flow gain digital poten-
tiometer did not adjust during device calibration. This
error only occurs during the calibration procedure.
C. AUTO-CALIBRATION
The DV54 PAP automatically adjusts calibration to maintain
accuracy over time and under varying operating conditions.
Each time the blower is turned OFF, the PC control board
reads and saves the offset voltages from the pressure trans-
ducer and the fl ow transducer. The PAP uses these voltages to
maintain calibration accuracy as the unit is used over time.
D. DETAILS ON TC SERIAL COMMAND
Tc serial commands are used in the manual calibration proce-
dure listed in Section A. The ' Tc ' command on the terminal
program reads the unit's current calibration values, starts the
calibration procedure, and handles user feedback during the
calibration process. Refer to the manual calibration procedure
for details on the calibration process.
• Sending ' Tc=s ' to the PAP starts the calibration pro-
cess.
• Sending ' Tc ' without a modifi er requests the current
calibration values. A comma-separated list of all cal
values is returned.
Comma-separated response to ' Tc ' with no modifi er:
llll,hhhh,mmmm< cr>
o llll is the pressure low cal (sensor offset). Convert
to voltage by dividing by 1024 and multiplying by 5.
o hhhh is the pressure high cal (sensor output at 20
cmH2O). Convert to VDC by dividing by 1024
and multiplying by 5.
o mmmm is the motor current calibration
(adc offset)
• Feedback is provided to the calibration task by sending
' Tc=y ' when prompted.
Description
LT-2027 15