Continental Hydraulics Installation Manual
Page 18 of 24
CEM-PA-B
CHI 1020688 01/2016
SIGNAL:U (Output polarity)
Command
Parameter
Unit
Group
SIGNAL:U X
x=
+ | -
-
EXP
This command is used to define the output polarity.
+
0 % to 100 %, normal output
-
100 % to 0 %, changed output polarity
CURRENT (Rated solenoid current)
Command
Parameters
Unit
Group
CURRENT
X
x= 500… 2600
mA
STD
The nominal output current is set. Dither and also MIN/MAX always refer to this current
range.
DFREQ (Dither frequency) / DAMPL (Dither amplitude)
Command
Parameters
Unit
Group
DFREQ
X
DAMPL
X
x= 60… 400
x= 0… 3000
Hz
0.01 %
STD
The dither
2
can be defined with this commands. Different amplitudes or frequencies may
be required depending on the valve.
The dither amplitude is defined in % (peak to peak value) of the nominal output current
3
(see: CURRENT command).
The dither frequency is defined in Hz. Depending on the internal calculations, the
frequency is adjustable in steps only
4
.
The PPWM and IPWM parameters influence the effect of the dither setting. These
parameters should not be altered again after the dither has been optimized.
2
The dither is a ripple signal which is superimposed on the current set point and is defined by the amplitude
and frequency: the dither frequency and the PWM frequency.
The dither frequency should not be confused
with the PWM frequency
.
In some documentations the PWM frequency is described as a dither. This can be
recognized by the lack of the dither amplitude.
3
The dither amplitude is a command signal. Derivations between the commanded amplitude and the real
amplitude are possible, depending on the dynamic of the solenoid.
4
The lower the dither frequency, the smaller the steps. Therefore no practical problems are expected.
