Continental Hydraulics CEM-PA-B User manual

Continental Hydraulics Installation Manual
Page 1 of 24 CEM-PA-B CHI 1020688 01/2016
CEM-PA-B
Product Description:
This closed loop PID amplifier, drives a single solenoid proportional pressure or flow
control valve coil up to 2.6A. It is suitable to provide precise closed loop control in
pressure, force, or velocity systems. This module uses traditional PID error correction to
provide stable control in dynamic systems.
A wide range of analog signals are accepted. User may select either voltage or current
input mode. These inputs are easily scaled to match system requirements. Input
command can be ramped. PID variables are adjustable over a wide range. The
Amplifier is easily switched from open loop to closed loop control.
Min and Max output current are adjustable. Output characteristics can be independently
customized. The module is disabled if the coil outputs are shorted or open. If command
current signal is outside of the proper range, the module is disabled. PWM and Dither
are user adjustable.
This module is easily adapted to a variety of system requirements. All variables are user
adjusted with easy to use software on your Microsoft Windows laptop. Control variables
are stored in non-volatile memory internal to the module. All variables can be read by
the laptop, and reproduced exactly on other modules.

Continental Hydraulics Installation Manual
Page 2 of 24 CEM-PA-B CHI 1020688 01/2016
Table of Contents
Information Description Page #
Technical Data ………………………………………………………………….. 3
Steps to install and configure a new application ……………………………. 4-5
Module Mounting Location …………………………………………………….. 5
Power Supply …………………………………………………………………… 5
Wiring to Valve ………………………………………………………………….. 5
Circuit Diagram …………………………………………………………………. 6
LED Definitions …………………………………………………………………. 7
Terminal Identification ………………………………………………………….. 7
Parameter List …………………………………………………………………… 8
Command Parameter Descriptions
LG (Language) ………………………………………………………….. 9
MODE ……………………………………………………………………. 9
SENS …………………………………………………………………….. 9
EOUT …………………………………………………………………….. 10
SYS_RANGE ……………………………………………………………. 10
SIGNAL:X / SIGNAL:W ………………………………………………… 10
AINMODE (Signal Scaling mode)……………………………………… 11-12
N_RANGE:X …………………………………………………………….. 13
OFFSET:X ……………………………………………………………….. 13
RA:UP / RA:DOWN (Ramp times) …………………………………….. 14
C:P, C:I, C:D, C:D_TI, C:D_FF ………………………………………… 15
C:I_LIM / C:I_ACT ………………………………………………………. 16
MIN ………………………………………………………………………...17
MAX ………………………………………………………………………. 17
TRIGGER ………………………………………………………………… 17
SIGNAL:U …………………………………………………………………18
CURRENT ……………………………………………………………….. 18
DFREQ / DAMPL ………………………………………………………...18
PWM ……………………………………………………………………… 19
ACC ………………………………………………………………………. 19
PPWM / IPWM ……………………………………………………………20
Process Data (Monitoring) ………………………………………………………20
Failure Monitoring ……………………………………………………………….. 21
Troubleshooting …………………………………………………………………. 22-24

Continental Hydraulics Installation Manual
Page 3 of 24 CEM-PA-B CHI 1020688 01/2016
Technical data
Supplyvoltage [VDC] 12… 30 (incl. ripple)
Current requirement [mA] 60 + solenoid current
External protection [A] 3 medium time lag
Reference voltage [V] 8 (max. 25 mAload)
Digital inputs [V] logic 0: < 2
[V] logic 1: > 10
Input resistance [kOhm] 25
[V] logic 0: < 2
[V] logic 1: > 12 (50 mA)
Analogue inputs:
Command value [V] 0… 10; 150 kOhm
[mA] 4… 20; 390 Ohm
Signal resolution [%] 0.006 incl. Oversampling
Sensor value [V] 0… 10; 90 kOhm
[mA] 4… 20; 390 Ohm
Signal resolution [%] 0.006 incl. Oversampling
PWMoutput [A]
0.5, to 2.6 Amp; broken wire and short circuit
monitored
PWMfrequency [Hz] 61… 2604
Sample time (pressure control) [ms] 1
Sample time (solenoid current
control)
[ms] 0.125
USB type B
Virtual COMport driver (CHI-PC):
9600… 57600 Baud (Default = 57600),
1 Stop bit, No parity,No handshake
Snap-on module to EN 50022
PA6.6 polyamide
Flammabilityclass V0 (UL94)
Weight [kg] 0,190
Protection class IP20
Temperature range [°C] -20… 60
Storage temperature [°C] -20… 70
Humidity [%] < 95 (non-condensing)
USB Typ B
4 x4-pole terminal blocks
PE: via the DIN mounting rail
EN 61000-6-2: 8/2005
EN 61000-6-4: 6/2007 + A1:2011
EMC
Digital outputs
Serial interface
Housing
Connections

Continental Hydraulics Installation Manual
Page 4 of 24 CEM-PA-B CHI 1020688 01/2016
Steps to install and configure a new application:
All parameters are adjusted using VEA-BUSB-A programming cable and CHI-PC Microsoft
Windows application.
1. Mount the module in suitable location. See page 5.
2. Connect the power supply, valve connections and enable.
3. Download and open the GUI program (www.continentalhydraulics.com/wp-
content/uploads/2015/01/setup-CEWMPC-10-v3.5.0.zip)
4. Connect to laptop via USB to USB Type B communication cable.
5. Select com port in upper left hand corner of the GUI program.
6. Open the Options Tab and verify that the correct com port, full Duplex and 57.6K Baud
rates are selected.
7. Connect with the CEM by selecting the connect button.
8. Click on the ID Button.
9. Adjust CURRENT parameter to match the nominal solenoid current.
10. Adjust dither amplitude, DAMPL, and dither frequency, DFREQ, to optimize performance
of valve.
11. Set the SIGNAL type to voltage (0-10V) or current (4-20ma). See ANIMODE if the
signals are other than standard. Some scaling may be required.
12. Set the MIN, MAX, and TRIGGER, for the desired system output.
13. Adjust the SYS_RANGE to the pressure output of the valve at rated current. For
example, the Continental model VER03M-210-A-K1-24D is rated for 210 bar. Set the
SYS_RANGE X to 210. The units on this parameter is bar.

Continental Hydraulics Installation Manual
Page 5 of 24 CEM-PA-B CHI 1020688 01/2016
14. Set the N_RANGE:X to the maximum pressure rating of the pressure sensor. For a 0-
210 bar pressure transducer, set N_RANGE:X to 210 bar. This setting should be the
same or greater than the SYS_RANGE value.
15. Use the OFFSET:X to compensate for the pressure transducer reading at actual 0bar
pressure.
16. Adjust RAMP as required.
17. Set internal monitor function, SENS, as required.
18. Adjust PID error correction parameters, (C:P, C:I, C:D, C:D_TI, C:FF), to tune the
system performance.
Module Mounting Location:
This module is to be mounted in a cabinet for protection from the local environment.
Ensure there is adequate free space around the module to allow for cooling air flow.
This module is designed to snap onto an industry standard 35mm DIN rail.
Do not mount near other modules that emit high power electrical interference, such as
motor controllers and high power contactors.
Power Supply:
This module is designed to operate on DC power from a regulated power supply ranging
from 12 to 30 volts. Match valve solenoid voltage rating to power supply, typically 12 or
24 volts. A 3 amp medium action fuse is recommended in the “+” power supply line.
Wiring to Valve:
Two conductors are required for each solenoid. There is no need for shielding on these
power conductors.
Wire size is chosen to provide an acceptable voltage drop between the module and the
valve solenoid. The following chart is based on 5% drop for 12v and 24v applications.
The listed cable length is distance from module to valve, and includes the voltage drop
of the return conductor.
Wire size 2.6A 12v 1.6A 24v 0.86A 24v
12 gauge 66 ft. max 215 ft. max 400 ft. max
14 gauge 49 ft. max 159 ft. max 295 ft. max
16 gauge 31 ft. max 100 ft. max 186 ft. max
18 gauge 19 ft. max 63 ft. max 117 ft. max
20 gauge 13 ft. max 39 ft. max 73 ft. max
22 gauge 8 ft. max 25 ft. max 46 ft. max
All analog input signal cables must be shielded!
Good analog system design requires that all analog signals in an electrically noisy
environment be shielded. Long wires act like antennas that pick up analog noise. The
wire connecting the analog command source to command this module must be shielded!
Shielding a noise sensitive wire is accomplished by wrapping a noise blocking foil or
braided shield around the signal wire. This shield must be grounded at only one end,
usually the end that sends the signal. A control cable may have many individual
conductors. The conductors may be shielded individually, or may be shielded as a
group. Short signal wires in electrically quiet environments may not need to be shielded.
The CEM family of modules all have an internal ground connection to the DIN rail. For
this module ground to be effective, please insure the DIN rail is properly grounded.

Continental Hydraulics Installation Manual
Page 6 of 24 CEM-PA-B CHI 1020688 01/2016
Circuit Diagram

Continental Hydraulics Installation Manual
Page 7 of 24 CEM-PA-B CHI 1020688 01/2016
LED Definitions
LEDs Description of the LED function
Identical to the READYoutput.
OFF:No power supplyor ENABLE is not activated
ON: System is readyfor peration
Flashing: Error discovered
Onlyactive when SENS = ON
YELLOW A Intensityof the solenoid current
1. Chasing light (over all LEDs): The bootloader is active. No
normal functions are possible.
2. All LEDs flash shortlyevery 6 s: An internal data error was
detected and corrected automatically! The module still works
regularly. To acknowledge the error the module has to be cycle
powered.
YELLOW A +
YELLOW B
Both yellow LEDs flash oppositelyevery 1 s: The nonvolatile stored
parameters are inconsistent! To acknowledge the error, data has to
be saved with the SAVE command or the corresponding button in the
CHI-PC.
GREEN
GREEN + YELLOW A
Terminal Identification - Input and output signals
Connection Supply
PIN 7 Power supply(see technical data)
PIN 8 0 V(GND) connection.
Connection Analogue signals
PIN 9 / 10
Pressure command value (WA), signal range 0… 10 V or 4… 20 mA,
scalable (SIGNAL W)
PIN 13 /14
Pressure feedback value (X), signal range 0… 10 V or 4… 20 mA,
scalable (SIGNAL X)
PIN 11 0 V(GND) connection for analogue signals
PIN 12 8Vreference voltage output
PIN 3 / 4 PWMoutput to the solenoid
Connection Digital inputs and outputs
Enable input:
Generallyenabling of the application.
RUN(Start) Input:
ON:The controller is active.
OFF:The controller is not active.
READYoutput:
ON:The module is enabled; there are no discernable errors.
OFF:ENABLE (PIN 15) is not active or an error has been detected.
PIN 15
PIN 6
PIN 5

Continental Hydraulics Installation Manual
Page 8 of 24 CEM-PA-B CHI 1020688 01/2016
CEM-PA-B Function Parameter layout
Ref Page Command Parameter Help / Description STD EXP
9LG EN EN English X X
9MODE EXP Standard / Expert mode X X
9SENS AUTO Malfunction monitoring [ON / OFF /AUTO] X X
10 EOUT 0 Output signal if not ready [0.01%] X
10 SYS_RANGE 100 System pressure [bar] X X
10 SIGNAL:X U0-10 Type of Input X X
13 N_RANGE:X 100 Sensor nominal pressure [bar] X X
13 OFFSET:X 0 Sensor offset [mbar] X X
10 SIGNAL:W U0-10 Type of Input X X
14 RA:UP 100 Command signal ramp time [ms] X X
14 RA:DOWN 100 Command signal ramp time [ms] X X
15 C:P 50 P gain [x 0.01] x X
15 C:I 4000 I gain [0.01ms] X X
15 C:D 0 D gain [0.1ms] X X
15 C:D_T1 500 D gain filter [0.1ms] x X
15 C:FF 8000 Feed forward [0.01%] X X
16 C:I_LIM 2500 Integrator limitation [0.01%] X X
16 C:I_ACT 2500 Integrator activation threshold [0.01%] X X
17 MIN 0 Deadband compensation [0.01%] X X
17 MAX 10000 Output Scaling [0.01%] X X
17 TRIGGER 200 Trigger point of the MIN function in 0.01% X X
18 SIGNAL:U + Output polarity X X
18 CURRENT 1000 Rated solenoid current [mA] X X
18 DFREQ 121 Dither frequency [Hz] X X
18 DAMPL 500 Dither amplitude [0.01%] X X
19 PWM 2604 PWM frequency [Hz] X X
19 ACC ON Auto Adjustment of the current loop [OFF / ON] X
20 PPWM 7 P-Gain of the current loop X
20 IPWM 40 I-Gain of the current loop X
MODE

Continental Hydraulics Installation Manual
Page 9 of 24 CEM-PA-B CHI 1020688 01/2016
Command Parameter Descriptions
LG (Changing the language)
Command
Parameters
Unit
Group
LG x
x= DE|EN
-
STD
Either English or German can be selected for the help texts.
After changing the language settings, the ID button in the menu bar (CHI-PC) must be
pressed (module identification).
MODE (Parameter view)
Command
Parameters
Unit
Group
MODE x
x= STD|EXP
-
STD
This command changes the operating mode. Various commands (defined via STD/EXP)
are blanked out in Standard Mode. The commands in Expert Mode have a more
significant influence on system behavior and should accordingly be changed with care.
SENS (Malfunction monitor)
Command
Parameters
Unit
Group
SENS x
x= ON|OFF|AUTO
-
STD
This command is used to activate/deactivate the monitoring functions (4… 20 mA
sensors, output current, signal range and internal failures) of the module.
ON: All monitoring functions are active. Detected failures can be reset by
deactivating the ENABLE input.
OFF: No monitoring function is active.
AUTO: Auto reset mode. All monitoring functions are active. If the failure doesn’t exist
anymore, the module automatically resumes to work.
Normally the monitoring functions are always active because otherwise no
errors are detectable via the READY output. Deactivating is possible mainly
for troubleshooting.

Continental Hydraulics Installation Manual
Page 10 of 24 CEM-PA-B CHI 1020688 01/2016
EOUT (Output signal if not ready)
Command
Parameters
Unit
Group
EOUT X
x= -10000… 10000
0.01 %
EXP
Output value in case of a detected error or a deactive ENABLE input. A value (degree of
valve opening) for use in the event of a sensor error (or the module is disabled) can be
defined here. This function can be used if, for example, the drive is to move to one of the
two end positions (at the specified speed) in case of a sensor error.
|EOUT| = 0 The output is switched off in the event of an error. This is normal behavior.
The output value defined here is stored permanently (independently of the parameter
set). The effects should be analyzed by the user for each application from the point of
view of safety.
SYS_RANGE (System pressure)
Command
Parameters
Unit
Group
SYS_RANGE X
x= 10… 1000
bar
STD
This command defines the maximum pressure of the selected valve at rated current
applied, which corresponds to 100 % of the input signal. If the demand is set incorrectly,
this leads to incorrect system settings, and the dependent parameters cannot be
calculated correctly.
SIGNAL (Type of input signal)
Command
Parameters
Unit
Group
SIGNAL:I X
i= W|X
x= OFF|U0-10|I4-20
-
EASY
This command can be used to change the type of input signal (voltages or current) and
to define the direction of the signal. This command is available for all analogue inputs (W
and X).
OFF= Deactivation of the input
See ANIMODE section if the signals used are not listed above, for re-scaling as required.

Continental Hydraulics Installation Manual
Page 11 of 24 CEM-PA-B CHI 1020688 01/2016
AINMODE
The AINMODE is used to define the type of analog input signals being used.
The standard default setting of AINMODE is EASY. In the EASY mode the SIGNAL:W/X/V (see
page 13) are only available in the most commom 0-10 volt or 4-20mA values.
If the input signal being used are not as listed, the AINMODE is available in the MATH mode
where the input signals can be scaled by a linear equation.
To enter the MATH option, you must change the AINMODE to MATH by use of the Terminal
Window. (see steps 1-4 below)
Once in the Termainal Window screen type in AINMODE MATH (ENTER), and click the Save
button. At this time you may go back to the Parameter screen where you can use the user
defined scalling feature.
Once in the MATH mode you will be able to scale the various input signals as shown below.

Continental Hydraulics Installation Manual
Page 12 of 24 CEM-PA-B CHI 1020688 01/2016
AINMODE - Analogue input scaling parameters
Command
Parameters
Unit
Group
FUNCTION
AIN:I a b c x
i = A|B
a= -10000… 10000
b= -10000… 10000
c= -10000… 10000
x= V|C
-
-
-
0.01%
-
EXP
AA
A-B
This command offers an individual scalable input. The following linear equation is used for the
scaling.
Output = A/B ∙ (Input – C)
The “C” value is the offset (e.g. to compensate the 4 mA in case of a 4… 20 mA input signal).
The variables Aand B are defining the gain factor with which the signal range is scaled up to
100 % (e.g. 1.25 if using 4… 20mA input signal, defined in default current settings by A = 1250
and B = 1000). The internal shunt for the current input signal is activated when parameters AIN:A
and AIN:B are set to Current (X=C).
The gain factor is calculated by dividing total input signal range (A) by the actual input range (B).
In the case of a 4-20mA with a single solenoid valve, the total range is 0-20mA, which means
A=20. The actual range is 4-20 mA, therefore, B= (20-4) =16. An offset, C, must be added to
compensate for the 0-4mA not being used of the full range. The offset is 4mA/20mA=0.2 or 20%.
Therefore C=2000 since the unit value for Cis 0.01%.
Shown in the below table are the most common input command signal and the corresponding
settings to be used.
Typical settings (examples):
Command
Input
Description
AIN:X 1000 1000 0 V
0… 10 V
Range: 0… 100 %
AIN:X 10 8 1000 V OR
AIN:X 1000 800 1000 V
1… 9 V
Range: 0… 100 %; 1 V = 1000 used for the offset and
gained by 10 / 8 (10 V divided by 8 V (9 V -1 V))
AIN:X 10 4 500 V OR
AIN:X 1000 400 500 V
0.5… 4.5 V
Range: 0… 100 %; 0.5 V = 500 used for the offset and
gained by 10 / 4 (10 V divided by 4 V (4.5 V -0.5 V))
AIN:X 20 16 2000 C OR
AIN:X 2000 1600 2000 C OR
AIN:X 1250 1000 2000 C
4… 20mA
Range: 0… 100 %
The offset will be compensated on 20 % (4 mA) and the
signal (16 mA = 20 mA –4 mA) will be gained to 100 %
(20 mA).
Each of this parameterization for 4… 20 mA is setting the
range to 0… 100 %.

Continental Hydraulics Installation Manual
Page 13 of 24 CEM-PA-B CHI 1020688 01/2016
N_RANGE:X (Sensor nominal pressure)
Command
Parameter
Unit
Group
N_RANGE:X X
x= 10… 10000
bar
EASY
N_RANGE (nominal range) is used to define the pressure range of the sensor. This
value should be always same as or higher than SYS_RANGE. The control parameter
cannot be calculated correctly in case of wrong values.
OFFSET:X (Sensor offset)
Command
Parameter
Unit
Group
OFFSET:X X
x= -60000… 60000
mbar
EASY
Adjustment of the zero point of the sensor. If the command signal and feedback signals
are not zeroed to each other this offset should be used.
Using of the commands SYS_RANGE, N_RANGE:X and OFFSET:X
Example of use:
With these commands, the feedback sensor is scaled. Suppose you have a pressure
control with the following characteristics:
The system pressure is 350 bar
The pressure sensor has a 4-20mA current output
The nominal pressure of the sensor is 600bar (20mA at 600bar)
The sensor has an offset of 3bar (at 0bar real pressure 3bar is displayed)
To scale this sensor correctly the following settings should be made:
SYS_RANGE 350 bar
SIGNAL:X I4-20
N_RANGE:X 600 bar
OFFSET:X -3000 mbar

Continental Hydraulics Installation Manual
Page 14 of 24 CEM-PA-B CHI 1020688 01/2016
RA (Command signal ramp time)
Command
Parameter
Unit
Group
RA:I X
i= UP|DOWN
x= 1… 600000
ms
STD
Two quadrant ramp function.
The ramp time is separately set for UP and DOWN ramps.
t
Ausgang/OutputA
A:UP A:DOWN

Continental Hydraulics Installation Manual
Page 15 of 24 CEM-PA-B CHI 1020688 01/2016
C:P, C:I, C:D C:D_TI, C:FF Control parameters (PID controller)
Command
Parameter
Unit
Group
C:I X
I= P|I|D|D_T1|FF
:P x= 0… 10000
:I x= 0… 30000
:D x= 0… 1200
:D_T1 x= 0… 1000
:FF x= 0… 10000
0.01
0.1 ms
0.1 ms
0.1 ms
0.01 %
STD
The control function will be parameterized via this command.
The C:P, I and D gain are similar to a standard PID controller.
The T1 factor is used for the D-gain in order to suppress high-frequency noise.
The FF value is a forward control value to control the output by the input signal directly.
The PID closed loop control function has only to adjust the difference (the error).
Value 0 deactivates the integrator.

Continental Hydraulics Installation Manual
Page 16 of 24 CEM-PA-B CHI 1020688 01/2016
C:I_LIM, C:I_ACT Integrator control function
Command
Parameter
Unit
Group
C:I_LIM X
C:I_ACT X
x= 0… 10000
x= 0… 10000
0.01 %
0.01 %
STD
The integrator function is controlled by this command.
C:I_LIM Limitation of the integrator range (faster control function by reduced pressure
overshoots). By a high nonlinearity of the valve the LIM value must be
sufficient to compensate it.
C:I_ACT Controls the integrator function. To reduce pressure overshoots, an activation
point for the integrator can be programmed via the (I_ACT) value. The
integrator is activated if the actual pressure is higher than the programmed
threshold:

Continental Hydraulics Installation Manual
Page 17 of 24 CEM-PA-B CHI 1020688 01/2016
MIN (Deadband compensation)
MAX (Output scaling)
TRIGGER (Response threshold for the MIN parameter)
Command
Parameters
Unit
Group
MIN:I X
MAX:I X
TRIGGER X
x= 0… 6000
x= 3000… 10000
x= 0… 3000
0.01 %
0.01 %
0,01 %
STD
With this command, the output signal is adjusted to the valve characteristics. With the
MAX value the output signal (the maximum valve current) will be defined. With the MIN
value the overlap (dead band of the valve) will be compensated. Via the TRIGGER the
activation point of the MIN function is set and so a non-sensitive range around the zero-
point
1
can be specified.
If the MIN value is set too high, it influences the minimal pressure, which cannot be
adjusted any longer. In extreme case this causes to an oscillating at small input values.
1
This dead band is necessary, in order to avoid unrequested activations caused by small variations of the
input signal. If this module is used in pressure controls, the TRIGGER value should be reduced (typical:
1…10).
Eingang / Input 100%
10V
Ausgang / Output
MAX
MIN
TRIGGER

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.

Continental Hydraulics Installation Manual
Page 19 of 24 CEM-PA-B CHI 1020688 01/2016
PWM (PWM Frequency)
Command
Parameter
Unit
Group
PWM X
x= 61… 2604
Hz
EXP
The frequency can be changed in defined steps (61 Hz, 72 Hz, 85 Hz, 100 Hz, 120 Hz,
150 Hz, 200 Hz, 269 Hz, 372 Hz, 488 Hz, 624 Hz, 781 Hz, 976 Hz, 1201 Hz, 1420 Hz,
1562 Hz, 1736 Hz, 1953 Hz, 2232 Hz and 2604 Hz). The optimum frequency depends
on the valve.
If the PWM frequency is less than 500 Hz, the dither amplitude DAMPL should be set to
zero.
The PPWM and IPWM parameters should be adapted when using low PWM frequencies
because of the longer dead times which forces a reduced stability of the closed loop
control.
ACC (Current loop auto adjustment)
Command
Parameter
Unit
Group
ACC X
x= ON|OFF
-
EXP
Operation mode of the closed loop current control.
ON: In automatic mode PPWM and IPWM are calculated depending on the pre-set
PWM-frequency.
OFF: Manual adjustment.

Continental Hydraulics Installation Manual
Page 20 of 24 CEM-PA-B CHI 1020688 01/2016
PPWM (P gain of the current loop)
IPWM (I gain of the current loop)
Command
Parameters
Unit
Group
PPWM X
IPWM X
x= 0… 30
x= 1… 100
-
-
EXP
The PI current controller for the solenoids is parameterized with these commands.
These parameters should not be changed without adequate measurement facilities and
experience.
Attention, if the parameter ACC is set to ON, these adjustments are done automatically.
If the PWM frequency is < 250 Hz, the dynamic of the current controller has to be
decreased.
Typical values are: PPWM = 1… 3 and IPWM = 40… 80.
If the PWM frequency is > 1000 Hz, the default values of PPWM = 7 and IPWM = 40
should be chosen.
PROCESS DATA (Monitoring)
Command
Description
Unit
WA
W
X
E
U
IA
Input signal
Command value
Feedback value
Control error
Output
Solenoid current5
mm
mm
mm
mm
%
mA
The process data are the variables which can be observed continuously on the
monitor or on the oscilloscope.
5
The display of the solenoid current (in CHI-PC program) is damped in order to be able to bring out a stable
signal.