Jaquet T411, Руководство по эксплуатации

Страница: 21 / 27

Operating Instructions T411 / T412 JAQUET AG
Revision: 003 21/27
9 Operating behavior
9.1 Power on
9.1.1 Analogue Output
After switching-on the tachometer, the output relates the lower value of the defined output range. After
completion of the first measurement the output goes to the corresponding measured value.
9.1.2 Relay Output
The parameter set determined by the configuration and binary input is valid from the start.
If the relay is assigned to a limit it remains deactivated until completion of the first measurement. After this it
switches to the status, which is defined under <Limit>.
If the relay is assigned to any other item in the status register it immediately switches to the corresponding
status.
If no input frequency is present, then after a period of 2 x Fixtime a measured value below the lower set point
is assumed.
9.2 Measurement
Every measurement begins with the positive edge of the input signal. The next positive edge closes the
current measurement and starts the next one after termination of the fixtime.
The resulting effective measurement time is dependent upon whether the input signal period is longer or
shorter than the Fixtime.
Input signal period < Fixtime Input signal period > Fixtime
Input
Frequency
End of Fixtime Ensuing edge
Fixtime
Input period time
Effective measurement period
t
Messung typisch
= Fixtime
t
Messung maximal
= 2 x Fixtime
Input
Frequency
End of Fixtime Ensuing edge
Period of input signal
Fixtime time Fixtime
Effective measurement period
t
Messung maximal
= 2 x Input signal period
The total measurement time has a resolution of

0.4

s.
The calculation and adaptation of outputs follows immediately after the Fixtime.
With input frequencies outside of the measuring range, the corresponding final values will be assumed.
9.2.1 The adaptive Trigger level
After triggering, the trigger level is set for the next pulse
anew.
This guarantees that the trigger level can follow a 50%
reduction in speed from pulse to pulse.
DC offset, resonance and negative pulses have no
influence on the triggering
t
trigger level
signal to
noise ration
bad sensor
signal
U
old trigger level