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Technical Documentation 

 

 

SCU-138-P 

 

Speed control unit with integrated power stage 

 

 

 

 

 

 

 

Summary of Contents for SCU-138-P

Page 1: ...Technical Documentation SCU 138 P Speed control unit with integrated power stage ...

Page 2: ...2 MODE Parameter view 19 5 2 3 SENS Malfunction monitor 19 5 2 4 EOUT Output signal if not ready 20 5 3 Input Signal adaptation 20 5 3 1 SELECT W command signal source selection 20 5 3 2 SIGNAL W Type of input signal 20 5 3 3 SYS_RANGE Working range 21 5 3 4 PWM ZERO scaling of the PWM input 21 5 3 5 PWM FULL 21 5 3 6 FIX_SPEED Internal demand value 21 5 3 7 RA Command signal ramp time 22 5 4 Cont...

Page 3: ... 5 6 7 IPWM I gain of the current loop 28 5 7 Special commands 29 5 7 1 AINMODE Scaling mode 29 5 7 2 AIN Analogue input scaling 30 5 8 PROCESS DATA Monitoring 31 6 Appendix 32 6 1 Failure monitoring 32 6 2 Troubleshooting 32 6 3 Description of the command structure 33 7 Notes 34 ...

Page 4: ...the module plus the terminal blocks which are part of the housing The Profibus plug interface cables and further parts which may be required should be ordered separately This documentation can be downloaded as a PDF file from www w e st de 1 3 Accessories WPC 300 Start Up Tool downloadable from our homepage products software Any standard cable with USB A and USB B connector can be used as the prog...

Page 5: ...06 2020 The data and characteristics described herein serve only to describe the product The user is required to evaluate this data and to check suitability for the particular application General suitability cannot be inferred from this document We reserve the right to make technical modifications due to further development of the product described in this manual The technical information and dime...

Page 6: ...on by trained specialist staff The instruction manual must be read with care The installation instructions and the commissioning instructions must be followed Guarantee and liability claims are invalid if the instructions are not complied with and or in case of incorrect installation or inappropriate use CAUTION All electronic modules are manufactured to a high quality Malfunctions due to the fail...

Page 7: ...oltage and a varying solenoid resistance The output stage is moni tored short circuit broken wire and switches off in case of detected error By the free parameterization of the power stage all typical proportional valves of the different manufactures can be optimal adapted Because of the easy handling a very short training period is guaranteed Typical applications Speed control using an impulse se...

Page 8: ...dy 1 2 3 4 5 6 7 8 9 10 11 12 14 15 16 13 D 41372 Niederkrüchten Homepage http www w e st de W E ST Elektronik 13 14 15 9 10 11 12 16 A B Klemmblöcke steckbar Terminals removable LEDs USB Interface Typenschild und Anschlussbelegung Type plate and terminal pin assignment 23 0000 mm 99 0000 mm 114 0000 mm ...

Page 9: ...rces frequency converters power contactors and cable lengths 3 m Inexpensive SMD ferrites can be used with high frequency radiation The screening should be connected to PE PE terminal as close to the module as possible The local requirements for screening must be taken into account in all cases The screening should be connected to at both ends Equipotential bonding must be provided where there are...

Page 10: ... value is read by an encoder If us ing two solenoids the closed loop controller gets activated directly with the ENABLE signal The digital START input is used for switching the solenoids in this mode DIR The integrated standard features are configured on the various parameters In case of a fault the power output stage will be deactivated and the fault will be indicated via deactivating the READY o...

Page 11: ... of the system redundancy and the connection diagram the following parameters The WORKING RANGE for the ANALOGUE INPUTS See specifications of the system and the sensors The output CURRENT and the typical valve parameters like DITHER and MIN MAX Pre parameterization is necessary to minimize the risk of an unintentional movement pressure Control signal Check the control signal output signal The cont...

Page 12: ...ata has to be saved with the SAVE command or the corresponding button in the WPC Connection Supply PIN 7 Power supply see technical data PIN 8 0 V GND connection Connection Analogue signals PIN 9 10 Command value WA signal range 0 10 V or 4 20 mA scalable alternatively PWM signal PIN 13 14 Feedback value X the actual speed is read in via a pulse transmitter 12 24 V PIN 11 0 V GND connection for an...

Page 13: ...tal Output USB type B SCU 138 P 6 13 Valve adaption Digital Input u Control program Ramp function PID control function ia ib to solenoid A c wa x 12 GND Ub 8 7 DC DC to solenoid B Power supply Power stage Digital Input Reference voltage 14 11 Setpoint Actual value Scaling Frequency Input Scaling 9 10 Differetial Input w e ...

Page 14: ...ND PIN 11 In PIN 9 In PIN 10 Joystick 4 20 mA input In PIN 9 In PIN 10 GND PIN 11 Alternative 3 wire connection of two solenoids Enable 8 7 6 5 16 15 14 13 12 11 10 9 Analogue command signal Solenoid 4 3 2 1 0V PE Power Supply 0V 12 V 24 V Pulse signal actual value Reference voltage output Ready A Solenoid B Start DIR Digital input output PE 0V 0V Example Hawe valves 3 4 1 2 A Solenoid B Solenoid ...

Page 15: ...V Hz Logic 0 2 V Logic 1 10 V max 1 mA 50 1000 Pulse input actual value V Hz Logic 0 2 V Logic 1 10 V max 1 mA 35 10000 measurement value limited to 6 kHz PWM output Max output current Frequency A Hz Wire break and short circuit monitored 2 6 61 2604 selectable in defined steps Controller cycle times Solenoid current control Signal processing µs ms 125 1 Serial interface Transmission rate kBaud US...

Page 16: ...Page 16 of 34 SCU 138 P 2230 05 06 2020 Connections Communication Plug connectors PE USB type B 4 x 4 pole terminal blocks via the DIN mounting rail EMC EN 61000 6 2 8 2005 EN 61000 6 4 6 2007 A1 2011 ...

Page 17: ... of 0 PWM FULL 10000 0 01 PWM duty cycle yielding a setpoint of 100 FIX_SPEED 0 0 01 Fix internal command value Ramp function RA UP RA DOWN 100 100 ms ms Command signal ramp times Control parameters PID controller C P C I C D C D_T1 C FF 100 4000 0 500 0 0 01 0 1 ms 0 1 ms 0 1 ms 0 01 P gain I gain D gain D gain filter Feed forward gain Integrator control C I_ACT C I_LIM C I_PRE 2500 2500 0 0 01 0...

Page 18: ...Dither frequency DAMPL 500 0 01 Dither amplitude PWM 2604 Hz PWM frequency ACC ON Current loop auto adjustment PPWM IPWM 7 40 P Gain of the current loop I Gain of the current loop Special commands Scaling mode AINMODE EASY Input scaling mode AIN W A 1000 B 1000 C 0 X V 0 01 Free scaling of the analogue input Gets activated when AINMODE is switched over to MATH ...

Page 19: ...ant influence on system behavior and should accordingly be changed with care 5 2 3 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 sig nal range and internal failures of the module ON All monitoring functions are active Detected failures can be reset by deactivating t...

Page 20: ...s always turned off in case of an error CAUTION 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 5 3 Input Signal adaptation 5 3 1 SELECT W command signal source selection Command Parameters Unit Group SELECT W X x ANA PWM PRE STD By this command the source for the...

Page 21: ...on the basis of the read in duty cycle of the PWM input These parameters are only visible and operational if the setpoint source PWM is selected via the parameter SELECT W The factory setting 0 10000 yields a proportional behaviour and 100 setpoint if the duty cycle is 100 that means a permanent signal This is only a theoretical value because a permanent signal means the absence of pulses and ther...

Page 22: ...2230 05 06 2020 5 3 7 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 Output A A UP A DOWN ...

Page 23: ... to suppress high frequency noise Entering a value of 0 in I deactivates the integrator Via the feed forward FF value the output is controlled directly The PID closed loop control function has only to adjust the difference the error This leads to a stable control behavior and also to a dynamic drive The value depends on the command value w Scaling Ramp x Scaling 0 10 V 4 20 mA C FF Pressure contro...

Page 24: ...the feedback signal is higher than the programmed threshold depending on the command value C I_LIM limits the working range of the integrator so that the controller can quickly react to the process with out any major overshoots If the value is too small it may have the effect that the non linearity of the system cannot be fully compensated C I_PRE defines a pre set value for starting the integrato...

Page 25: ...th 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 point1 can be specified CAUTION If the MIN value is set too high it influences the minimum speed which cannot be ad justed any longer In extreme cases this could cause an oscillation at small input values 1 This dead ba...

Page 26: ...aracteristic curve If two solenoids are used it effects the switching of the solenoids 1S One solenoid standard o U 0 100 IA 0 100 1S One solenoid inverted o U 0 100 IA 100 0 2S Two solenoids standard o PIN 6 not set Controlling IA 0 100 o PIN 6 set Controlling IB 0 100 2S Two solenoids switched o PIN 6 not set Controlling IA 100 0 o PIN 6 set Controlling IB 100 0 CAUTION Controlling the second so...

Page 27: ...the nominal output cur rent see CURRENT command The dither frequency is defined in Hz Depending on the internal calcula tions the frequency is adjustable in steps only CAUTION 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 CAUTION If the PWM frequency is less than 500 Hz the dither amplitude D...

Page 28: ...t 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 preset PWM frequency OFF Manual adjustment 5 6 6 PPWM P gain of the current loop 5 6 7 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 co...

Page 29: ...scaling The AINMODE is used to define the kind of parameterizing of the analogue inputs The EASY mode DEFAULT supports a simple and application oriented input scaling The MATH mode supports the free input scaling by a linear equation This mode is compatible to our older modules Attention This command can be executed in the terminal window only In case of switching back DEFAULT data should be reloa...

Page 30: ...sable are 0 20mA means A has the value 20 Really used are 4 20mA means B has a value of 16 20 4 Not used are 0 4mA In a range of 20mA this is an offset of 20 means a value of 2000 for C Last but not least X has to be set to C choosing current signal In this case AIN command would look like this AIN I 20 16 2000 C or AIN I 1250 1000 2000 C see below Typical settings Command Input Description AIN W ...

Page 31: ...tion Command value Feedback value Feedback value Control error Controler output Output to valve Solenoid current3 A Solenoid current B Hz Hz mA mA The process data are the variables which can be observed continuously on the monitor or on the oscilloscope 3 The display of the solenoid current in WPC 300 program is damped in order to be able to bring out a stable signal ...

Page 32: ...sheets The RC in monitor mode can be used to analyze faults CAUTION All safety aspects must be thoroughly checked when working with the RC Remote Control mode In this mode the module is controlled directly and the machine control cannot influence the module FAULT CAUSE SOLUTION ENABLE is active the mod ule does not respond and the READY LED is off There is presumably no power supply or the ENABLE ...

Page 33: ...sed for an arbitrary command name expandable by an index Indexed commands are indicated by the sign i oder I is a dummy for the index E g an index can be A or B depending on the direction x parameter value in case of special commands more than one parameter are possible Examples MIN A 2000 nnnn MIN i A and x 2000 OFFSET 50 nnnn OFFSET and x 50 C IC 2000 nnnn C i IC and x 2000 ...

Page 34: ...Page 34 of 34 SCU 138 P 2230 05 06 2020 7 Notes ...

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