Mindray Passport 5-Lead, Руководство по обслуживанию

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Passport 5-Lead, 5L, LT, XG Service Manual 0070-00-0420 7 - 19
Calibration Diagnostics and Calibration Procedure
7.5.9.2 DAC Test
The purpose of this test is to verify the performance of the AC on the SpO2 Board.
a.
Connect an oscilloscope to J24 pin 5 of the SpO2 Board. The signal should appear
as shown in Figure 7-14. Make sure the saw signal is smooth and does not jump or
drop suddenly which would indicate a fault DAC bit.
b.
Press the END key to return to the SpO2 Test Menu.
FIGURE 7-10 DAC Waveform
7.5.9.3 Shared RAM Test
When this diagnostic is selected the SpO2 menu will be covered by the Shared RAM Test
Menu which offers a choice of three different SpO2 RAM Test;Memory Test 1 (00H,FFH),
Memory Test 2 (Walking Ones), and Memory Test 3 (Address Test).
NOTE: This test erases the normal operating code that was
downloaded to the shared RAM that enables the other SpO2
tests. After performing any of the memory tests the unit
must re-power the Run, the Accuracy, Sensor, or DAC tests.
Memory Test 1 (Basic RAM Test): The main processor will perform the basic write/read test
to each memory location with data pattern 0 and 0xFF to verify the integrity of the RAM.
Memory Test 2 (Databus Test): The main processor will write a bit pattern of walking one’s
(8-bit) to each memory location and read it back to verify that the data bus is not cross
talking.
CH1
J24 pin 5
2V/DIV
5 sec/DIV