ONOSOKKI TS-3200A, Инструкция по эксплуатации

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• Time constant
When a step torque signal is applied to the torque detector as shown above, the analog output changes as
shown in Fig. 2. In this case, the time period until the the analog output reaches 63% of the output voltage
is referred to as time constant (
τ
). With a time constant setting of
τ
=16ms, for example, the time period
until the analog output reaches 63% of the output voltage is 16ms when a step torque signal is applied to
the torque detector as shown above.
The time constant is obtained through digital filter processing using the following exponential averaging:
Exponential averaging: A
n
= A
n-1
+(M
n
-A
n-1
)/K
The nth analog output, A
n
, is obtained by subtracting the exponential average of up to (n-1)th analog
output, A
n-1
, from the nth measurement value, M
n
, dividing by the averaging coefficient, K, then adding
A
n-1
.
M
n
is the data obtained at each 4ms sampling interval and K time constant setting
τ
. When
τ
=16ms, K
equals 4.
In terms of general filter characteristics, there is the relationship between cutoff frequency fc and time
constant
τ
.
τ
=1/2
π
f
c
For example, when
τ
=16ms, f
c
nearly equals 10Hz.
Average processing by exponential averaging has the 1st order low-pass characteristic of the filter.
• Allowable ranges
0:OFF* 1:16ms 2:31ms 3:63ms 4:125ms 5:250ms 6:500ms 7:1s 8:2s 9:4s A:8s B:16s C:32s D:64s
* Only when the TS-0321 high-speed response option is installed, 0:OFF is displayed.
When 0:OFF is selected, a response with 4ms sampling time results.
Note: The operation methods for digital display and analog output are as follows:
* Digital display value: Simple arithmetic average of high-speed sampled torque and rpm
(at each gate time)
* Analog output value: Exponential average of high-speed sampled torque and rpm (with
a time constant setting)
Step torque or rpm Analog output
Fig. 1 Fig. 2
63%
100%
t=0
t=0 4ms 4ms
Sampling time
Operation time