Velleman PCS100A pcs100 - pcs500 - k8031 - Manual (Page 24)

PCS500 / PCS100 / K8031
24
Troubleshooting
No signal on the oscilloscope display
No communication with the computer (check that the cable is connected to
parallel printer port (LPT)
Check the printer port setting in the BIOS SETUP of the computer. Select
standard parallel port mode (SPP), also named "compatible" mode or
"Centronics" mode.
•
Program is not in RUN ON
•
The channel concerned is OFF
•
TIME/DIV switch is in the wrong setting.
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TRIGGER is ON, set TRIGGER OFF
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The unit input selection is at GND.
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Y position is wrongly adjusted.
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Input amplitude is too large, adjust VOLTS/DIV setting.
If the above tips have no effect, then test on a different computer or replace the
printer port card.
The voltage readout does not correspond to the actual value.
•
The probe is in the X10 position
•
Note, the RMS readout measures only the AC voltage.
•
The oscilloscope must be calibrated.
Errors in Recorder time scale
When recording at short time base (< 2s/div) the sampling interval is 10ms.
This is possible only on fast computers. Anyhow, do not execute other
applications during the recording process; it may influence the measuring
time scale.
The time base of the measurements is generated by the internal timer of the
computer. This timer can be put on hold by other processes on the computer.
This can cause a deviation in the time measurement.
To ensure the precision of the time measurement at short time base:
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Use a fast computer: 486 or Pentium.
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Do not run other applications when recording
•
Prevent your computer from going into power saving mode