ifm
System Manual
ecomat
mobile
SmartController (CR2500) V05
PWM in the ecomatmobile controller
PWM signal processing
163
Calculation examples RELOAD value
ClassicController
ExtendedController
SafetyController
CabinetController (CR0303)
SmartController
CabinetController (CR0301/CR0302)
PCB controller
The PWM frequency shall be 400 Hz.
20 MHz
_________ = 50 000
10
= C350
16
= RELOAD
400 Hz
Thus the permissible range of the PWM value
is the range from 0000
16
to C350
16
.
The comparison value at which the output
switches must then be between 0000
16
and
C350
16
.
The PWM frequency shall be 200 Hz.
10 MHz
_________ = 50 000
10
= C350
16
= RELOAD
200 Hz
Thus the permissible range of the PWM value
is the range from 0000
16
to C350
16
.
The comparison value at which the output
switches must then be between 0000
16
und
C350
16
.
This results in the following mark-to-space ratios:
Mark-to-space ratio
Switch-on time
Value for mark-to-space ratio
Minimum 0
%
C350
16
Maximum 100
%
0000
16
Between minimum and maximum triggering 50 000 intermediate values (PWM values) are possible.
PWM channels 4...7 / 8...11
These 4/8 PWM channels can only be set to one common PWM frequency. For programming, the
functions PWM and PWM1000 must not be mixed.
0000
FFFF
100%
0%
Reload
Wert / Value
Figure: RELOAD value for PWM channels 4...7 / 8...11
The RELOAD value of the internal PWM counter is calculated (for all
ecomat
mobile
controllers) on
the basis of the parameters DIV64 and the CPU frequency as follows:
DIV64 = 0
RELOAD = 10 000
16
– ( 2.5 MHz / f
PWM
)
DIV64 = 1
RELOAD = 10 000
16
– ( 312.5 kHz / f
PWM
)
Depending on whether a high or a low PWM frequency is required, the input DIV64 must be set to
FALSE (0) or TRUE (1). In case of PWM frequencies below 39 Hz, DIV64 must be set to "1" to ensure
that the RELOAD value is not smaller than 0000
16
.
Содержание Ecomat Mobile Series
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