Burkert Type 8620 - Manual (Page 78)

mxCONTROL Type 8620
Page 78
control output is changed only be this max. permitted value. The maximum manipulating speed can be
configured separately for rising and falling control outputs.
The opening time parameter
Topen
is to be set to the time value required to change the control
output from 0% to 100% with the max. permitted manipulating speed.
The closing time parameter
Tclose
is to be set to the time value required to change the control
output from 100% to 0% with the max. permitted manipulating speed.
If no control output limitation is required, the parameters
Topen
and
Tclose
are to be set to
0 s
.
13.3.4 Transistor output as fast PWM Output
The range of the PWM-Frequency (f = 1/T2) can be set between 20 ... 2250 Hz are configured
(corresponds to a Period duration between 50 … 0.45 milliseconds), but only certain frequency
values of this range are supported - when entering a new frequency the firmware automatically selects
the next supported frequency.
The output resolution of pulse length T1 is 8 bit (i.e. 256 steps).
Limitation of the manipulating speed
Refer to chapter 13.3.3 „Limitation of the manipulating speed“.
Time t
T1
T2 T2 T2
T1 = Tpulse
T2 = Tperiod
= 1/Freq
0
1
Transistor Output
with constant
time (T2)
T1 T1 T1
T1 - variable
T2 - constant
Transistor outputs in fast PWM
mode are used for e.g. controlling
proportional valves.
The figure shows the transistor
outputs in PWM / fast PWM output
mode.
Figure 24: Transistor output as "Fast
PWM" output in normal mode.