Metrix OX9302-BUS, User Manual

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Appendix - "Bus analysis" mode
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12.7.3. Measurements (Ethernet 10Base-T)
Diagnosis
Use this table to troubleshoot problems on a measurement :
Measurement Description Diagnosis
VLevel
Measurement of the amplitude on the
signal’s thin pulses

Termination problem

Junction connection (oxidation, bad contact,
etc.)

Cable length not compliant with standard

Significant noise (check the cable route, ground
braid not connected, faulty chassis-ground, etc.)

…
Time Rise
Rise time between 10% and 90% of
the signal amplitude

Unsuitable or damaged cable (the rise and fall
times increase with the cable impedance)

Termination impedance incorrectly positioned

…
Time Fall
Fall time between 90% and 10% of
the signal amplitude
Time Data
Measurement made using the bit time
total. The bit time is measured on one
period (Manchester coding).
The measurement is only made on
thin pulses.

Unsuitable or damaged cable

Significant noise (check the cable route, ground
braid not connected, faulty chassis-ground, etc.)

…
Jitter
Measurement made using the bit time
total

Significant noise (check the cable route, ground
braid not connected, faulty chassis-ground, etc.)

…
Dist
Measurement of the amplitude
distortion.
The max overshoot level is compared
to the signal peak-to-peak value. The
measurement is only made on thick
pulses.

Unsuitable cable impedance

Termination problem (if there is no termination,
major overshoot and the opposite if the bus
impedance is too high)

Significant noise (check the cable route, ground
braid not connected, faulty chassis-ground, etc.)

…