ES441.1 - User’s Guide52
Functional Description ETAS
“X4” Counter Mode
In counter mode “X4”, the ES441.1 is configured as an up-/down-counter
whose measurement channel and its assigned second channel are analyzed as
equal channels. Both edges of the signals at the measurement channel and at
the assigned second channel are evaluated according to different rules. The
phase difference of the signals of the two channels determines the count direc-
tion.
Rules for evaluating signal edges at the measurement channel:
• The counter is incremented when the signal edges at the measurement
channel and the signal at the qualifying channel do not have an identical
state and
• decremented when the signal edges at the measurement channel and the
signal at the qualifying channel have an identical state.
Rules for evaluating signal edges at the qualifying channel:
• The counter is incremented when the signal edges at the qualifying chan-
nel and the signal at the measurement channel have an identical state and
• decremented when the signal edges at the qualifying channel and the
signal at the measurement channel do not have an identical state.
In the calibration software, the type of counter resetting can be selected for this
counter mode:
• Resetting the counter after every sampling point or
• Counter in Free Running Mode (no resetting of the counter).
Fig. 5-20 X4 Counter Mode
Prerequisites for using counter mode X4:
• The signal at the measurement channel and the signal at the qualifying
channel have the same signal shape
and
• the phase difference between the two signals is around a quarter of the
period duration of the frequency of the signal at the measurement chan-
nel.
Time
Input
Signal
Active
Inact ive
3 7 11
Qualif ying
Signal
Time
Active
Inact ive
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