RA 29 894/06.98 Digital Amplifier for RA Position and Pressure/Force Control 29 894/06.98 Model DPR, Series 1X Replaces: 04.97 – Achievable position accuracy of ±0.05% with analog feedback* – Achievable steady state, pressure accuracy of ±0.1%* * (typical, but not guaranteed) – High resolution analog input for 10 VDC position transducer – Fine Positioning integration for superior accuracy – Active Damping for low natural frequency cylinders – Gain matching for differential area cylinders – Pressure limiting – Accepts 2 pressure transducers or load cell as force feedback – Digital platform – Programmed by pushbuttons and front display – RS485 communication – Password protection available – 24 VDC power – Optimizes hydraulic axis for closed loop control – Configurable for any valve family – Proportional valve with closed center spool is normally preferred Digital Amplifier Card, Model DPR Ordering code Technical data Power supply voltage: V 21 V to 35 V DPR –1X (valve type ) DC Power requirement: P 10 to 60 W Digital Amplifier for Position and Pressure Regulation (depends on valve) Input control signal: V 0 to 10 V (±10 V) Series IN (10 to 19 externally interchangeable) Input impedances: Analog Voltages R 200 kΩ or higher Valve Type (partial list) IN Discrete (10–35 V) inputs R 1 kΩ or higher Specify valve to series number or abbreviate as follows: D 4WRAB6 E12 - 1X or WRAB6-E Internal reference voltage: V ±10 V REF 4WRA6 E20 - 1X or WRA6-E Minimum load on ±10 V: R 400 Ω L 4WRA6 E30 - 2X or WRA6-E-2X from card ±10 V @ ±25 mA 4WRA10 E40 - 1X or WRA10-E Fuse (5 mm x 20 mm): 3 A 4WRD10 E100L - 5X** or WRD10-E-5X Connector type: 32-pin, rows “a” and “c” 4WRE6 E32 - 1X or WRE6-E (DIN 41612, type C) 4WRE10 E64 - 1X or WRE10-E Card dimension: Euro card 4WRSE10 E80 - 3X or WRSE-E (DIN 41494) 100 mm x 160 mm 4WRTE10 E100L - 3X** or WRTE-E Space requirements: 4WRZ10 E85 - 3X or WRZ-E Height 3U 5.05 in. (128 mm) 4WS2EM6 - 1X/..E or WS2EM6-E Conductor side 1 division 0.20" 4WS2EM10 - 1X/..D or WS2EM10-D (5.08 mm) **Linear L-flow type recommended. Component side 7 divisions Example: DPR -1X/ 4WRE10-E32/1X or DPR - 1X/ WRE10-E Face plate 8HP 8 divisions Ambient temperature range: T 32 to 122 °F Ordering information (0 to 50 °C) Storage temperature: –4 to 158 °F Every DPR card includes a valve amplifier or driver board. (–20 to 70 °C) From the valve model, Rexroth determines which driver board to install and how to configure the valve parameters. The valve Weight (approx.): W 0.6 lb (0.27 kg) model can be abbreviated. In most cases, it is best to always include the valve type, valve size, spool type and design series. 1/12 DPR.tiff RA 29 894/06.98 Description Direct Drive does not use position feedback. This is an open loop The Rexroth DPR digital amplifier optimizes the hydraulic axis for analog position, pressure or force control. All analog inputs are 10 velocity control. It can also be combined with pressure control VDC. All card settings can be accessed with the onboard functions. New cards are normally configured as Direct Drive, only. pushbuttons and a digital display. The valve amplifier or driver Position Control requires 10 V feedback. Position control may be board is included and optimized by Rexroth. used alone or with pressure control functions. The transition Configuration for the application and commissioning are the between position and pressure control is shock free, depending on responsibility of the user. This includes the correct mechanical, the valve and system. For example, if a low dynamic valve like hydraulic and electrical installation. 4WRZ is wide open, some pressure overshoot is expected when the cylinder suddenly stops. The position controller can also be While the DPR contains advanced control options that can deliver externally disabled by a discrete input. This override is immediate. impressive performance, it can only work within the limits of the It does not permanently alter the internal configuration. given system. Note that proportional valves with closed center spools are normally preferred, except when only using Force Position applications can also include a velocity limit. The maximum velocity is limited by a ramp which changes the position Regulation. Consult Rexroth for further analysis to determine the command over time Δv = Δx/Δt. However, acceleration and best valve and system configuration for the desired performance. deceleration are still determined by the closed loop system. Applications - Selections for the application are made in the Velocity is not regulated. Setup menu. Some common examples include: Note that true synchronizing is not possible within the DPR. • Direct drive, only (no feedback) External control would be required to monitor feedbacks and • Position regulation, only (analog position feedback, 10 VDC) correct the relative position command for each axis. • Pressure regulation, only (1 pressure transducer, 10 VDC) CNC Drive is a special DPR configuration for interfacing to a • Force regulation, only (2 pressure transducers motion controller or computer numerical controller. The DPR or 1 load cell) optimizes the hydraulic axis and drives the valve. The CNC or • CNC drive, only (feedback to CNC) controller accepts the axis feedback. For high accuracy, digital with pressure limiting, either side feedback is required. A typical hydraulic axis uses a Rexroth with pressure limiting, both sides; cylinder with an integral absolute SSD (serial synchronous data) • Direct drive or or force limiting feedback and a CLM 4-axis or 2-axis controller. Other controllers Position regulation or with clamp control on +side only should use a simple position gain or Proportional gain for CNC drive with clamp on +side, pressure regulation. The CNC error of ±10 V connects to Input #5. The DPR limiting on –side compensates for valve symmetry, throttle characteristics and spool overlap. It also provides gain matching for differential area cylinders. Direct Drive with Force Override Pressure Pressure Transducer Transducer 0 ~ 10 V 0 ~ 10 V V V p p +Side –Side A B Application ab Optimization Direct #4 Direct Drive V Command Valve PT V 0 ~ –10 V Driver Pressure/Force Controller #3 Force V Command #2 V V 0 ~ –10 V V Enable #1 V V Auto / Auto 24 V Inputs –Jog / Pos. Off +Jog / Press Off DPR -1X/ (valve type) 2/12 RA 29 894/06.98 Description Position Control with Force Override Pressure Pressure Transducer Transducer 0 ~ 10 V 0 ~ 10 V V V p p 0 V 10 V Position Feedback #5 V V 0 ~ 10 V +Side –Side A B Position Application ab Controller Optimization Position #4 V Command Valve PT V 0 ~ 10 V Driver Direct Drive Pressure/Force Controller #3 Force V Command #2 V V 0 ~ –10 V V Enable V V Auto / Auto 24 V #1 Inputs –Jog / Pos. Off +Jog / Press Off DPR -1X/ (valve type) CNC Drive with Force Override Pressure Pressure Transducer Transducer 0 ~ 10 V 0 ~ 10 V V V Incremental, p p Absolute, SSD or SSI Position Digital Feedback Feedback to CNC +Side –Side A B CNC Application ab Drive Optimization #5 CNC Error V Valve PT 0 ~ –10 V V Driver Pressure/Force Controller #3 Force V Command #2 V V 0 ~ –10 V V Enable #1 V V Auto / Auto 24 V Inputs –Jog /Pos. Off +Jog / Press Off DPR -1X/ (valve type) 3/12 RA 29 894/06.98 Description The DPR can include both passive and active damping. It also +Velocity parameter. The –Ramp works as the –Velocity uses Fine Positioning for superior accuracy. Of course, CNC Drive parameter. No ramp is used with the CNC Error input. The can also be combined with DPR pressure control functions. Note Pressurization Ramp and Decompression Ramp are available for that the CNC must accept the greater following error of a typical pressure and force commands. The range of these ramp times is hydraulic axis, especially while pressure is being limited. Refer to 0 to 30 seconds. The Jog Ramp limits acceleration and the DPR Setup Instructions regarding, moving J3 to the “A” deceleration when moving with Jog commands. The Jog ramp is position. the same for both directions. Jog Ramp has a range from 0 to 30 seconds. Pressure regulation is essentially the same as pressure limiting. It may be used alone or combined with Direct Drive, Position Control Fine Positioning - This can greatly improve position accuracy. or CNC Drive. If pressure must be limited on both sides of a Without this advanced option, accuracy is a direct function of the cylinder, a shuttle valve may be used with a single pressure optimized Proportional gain alone. Additional Proportional gain transducer. The DPR can also accept two pressure transducers. can cause over-shoot. With Fine Positioning enabled, a switching integrator reduces the position error without requiring increased Clamp Control is a form of pressure control suitable for some Proportional gain. An overlapped spool is preferred for this option. clamping applications. Clamp control is only available on the For greatest accuracy, proper shielding, grounding and wiring +side. The only difference between Clamp Control and Pressure practices must be observed. Limiting is that the valve spool is not allowed to shift over-center, while commanded to move in this +direction. Maximum pressure Active Damping - This is an advanced feature that can improve relief protection for the +side of the cylinder may be advisable. The position accuracy. The active compensation can allow higher load induced pressure could exceed the commanded pressure Proportional gain for greater performance. Active Damping limit! Normal pressure limiting is still available for the –side. One requires two pressure transducers or a load cell, even if force or example of Clamp Control is for an injection molding machine pressure control is not desired. Cylinders with low natural where the clamp must not open during injection. This could occur frequencies that use high response valves normally benefit the if a sufficient external force acted against the clamp direction. most from active damping. Clamp Control limits pressure on the +side while moving or Valves - Typical proportional valves include: 4WRAB, 4WRA, clamped. To prevent the mold pressure from opening the mold, 4WRE, 4WRSE, 4WRD, 4WRKE, 4WRTE, 4WRZ. For position this spool can not shift through center. The position command control with DPR, use the proportional valve with an E-spool or must remain greater than the actual clamp position, to stay in this positive overlap for best results! This includes position applications pressure mode. with force regulation, CNC applications with pressure limiting, and An internal preset for pressure command is available when a fixed direct drive with pressure limiting. For pressure or force regulation pressure settings is desired. Each side or direction has a separate only, use a zero or underlap spool design, like the V-spool. A more preset for this command. These presets can eliminate the need dynamic proportional valve is preferred when pressure or force for the analog connection to input #3 when the DPR is also used control is involved. Although servos can be used in any case, they for Direct Drive, Position Control or CNC Drive. The preset goes may only be required for very small flows or special applications. through the pressure ramp function to control the rate of change The DPR could be used with proportional relief valves in some when enabled or disabled by the corresponding discrete input. pressure applications. The Counterbalance parameter provides a fixed offset to pressure. Position Feedback - The position transducer should be 0 to 10 Unlike the presets, this is located after the pressure ramp. This VDC. The DPR has excitation voltage for potentiometer feedback. parameter is similar to using a counterbalance valve. Note that the Most single rod cylinders for position control are fitted with a DPR can not hold this offset under all conditions, as during a power magnostrictive feedback device. This has many advantages and failure. This may not be a problem for all applications or when using normally works well. Special considerations may be required for directional proportional valves with closed center spools. The critical applications where high acceleration or sudden situation may be quite different when using a servo valve or temperature changes are expected. proportional pressure relief valve. Pressure Feedback - Pressure transducers should be 0 to 10 The pressure or force controller can be externally disabled by a VDC. A 0 to 5 VDC transducer can be used, but resolution is discrete input. Like the position control option, the override is reduced. There are two pressure transducer inputs. The unused immediate. For example, you may want to disable the pressure transducer input can be disabled. For pressure regulation only, limit for a short time to assure maximum acceleration, then release select “Force Only” under the menu for application and enable the the override before approaching the final position with the pressure desired feedback input. For Direct Drive, Position Control or CNC limit operating. Drive with Pressure control, first select “Direct Drive”, “Position Ctrl” or “CNC Drive” then enable the desired transducer input. Force regulation requires a load cell, two pressure transducers or a differential pressure transducer. When selecting this menu Force Feedback - Most force control applications will use two option, it is not necessary to configure Force Limiter options in the pressure transducers that output 0 to 10 VDC. The DPR sets the Setup menu. The DPR will automatically be set to external analog pressure ratio for Inputs #1/#2, to accommodate differential controller for both sides. Input #1 is normally used as the ±10V cylinders. Load cells should be 0 to ±10 VDC. Force feedback input. Analog Inputs - All analog inputs are bipolar, 0 to ±10 VDC Ramps - The +Ramp and –Ramp limits acceleration and differential type. The position feedback is a special high resolution deceleration in Direct Drive. Acceleration is the same in both design. For greater accuracy with 0 to 10 VDC devices, force inputs directions. Deceleration is independently adjusted. These ramp #1 and #2, and position inputs #4 and #5, can be re-configured as times range from 0 to 100 seconds. The +/–Ramp function can be uni-polar. Refer to DPR Setup Instructions regarding jumpers J5, used for Position Control. In this mode, the traverse velocity is J6, J7, J8. limited by changing position over time. The +Ramp works as the 4/12 RA 29 894/06.98 DPR functional diagram 5/12 Ramp Position Direct Drive Command or V Direct Drive V Command Position (#4) Auto Off II ON ON Window Linearization Position Feedback or V PID CNC Error Application V (#5) Configuration Position Error Controller Null Position (CNC only) Fault Active Valve Window Damping Optimization (Position only) Enable Valve Driver Pressure Transducer V Pressure or Load Cell V Calibration Damping Fault (#1) Window Pressure Pressure Controller V Transducer V (#2) PI Pressure Pressure +Cmd Auto Off Ramp Pressure Preset or Force V Command V +Jog Jog –Cmd –Jog (#3) Speed Ramp Preset Speed Auto Counter- balance +Jog –Jog RA 29 894/06.98 Description Before connecting the PLC analog or external analog source to the When power is applied, the display shows the configuration: DPR differential inputs, determine if the analog common is Rexroth DPR, firmware version, valve type, driver board required. isolated. An isolated or floating analog common should be Then a default display value can appear, like Valve Command grounded at one point. It is recommended to connect an isolated [%]. Units are indicated with the option name. The display analog common to 0 VDC or to the ground bus, at one point. eventually returns to the default value, unless the buttons are touched. Access the “Display..” option under the main menu. The Discrete Inputs - These are 24 V (10 to 35 V) inputs. default can be changed to other options like: Valve Feedback [%], ENABLE input (pin-22a) must be selected or high to allow motion Direct Command [V], CNC Error [mV or V], Position Command from analog inputs. In most installations, this is activated by a PLC [V], Position Feedback [V], Position Error [mV or V], Force permissive. After a DPR fault is cleared, the ENABLE input will Command [V], Force Feedback [%], Force Error [%], Transducer reset the card. #1 [V], Transducer #2 [V]. Only the available options for the AUTO (pin-24a) is energized for normal operation and is de- application will appear. The DPR can also continuously scroll the energized to allow jog functions. text during startup by selecting “Configuration”. After an idle time, the display may dim. Press any key to restore the display to full –JOG inputs (pin-26a) and +JOG (pin-28a) move the valve with the brightness. This feature can be disabled. corresponding internal jog speeds. The AUTO input must be off to allow jog. Faults - When a fault is detected, the valve driver is disabled. FAIL will flash on the display until ENTER is pressed. The detected fault These same inputs (pin-26a and pin-28a) have another function is continuously scrolled across the display in clear text, until after the AUTO input has been selected. Input pin-26a or “Pos. ENTER is pressed again. Cycle power or lower the ENABLE input Off”, disables the Position Controller, if AUTO is selected. Input to reset the DPR, after clearing a fault. Some faults are related to pin-28a or “Press Off”, disables the Pressure Controller, if AUTO the application and user settings, like Position Fault or Pressure is selected. Fault. Other faults are related to the valve, like Solenoid Fault, When AUTO is “off”, Driver LVDT or Driver Loop. The DPR verifies internal calibration Input (pin-26a) is energized for -JOG and EEPROM memory during power up. It also continuously Input (pin-28a) is energized for +JOG monitors the internal reference voltages. When AUTO is “on”, Communications - An RS485 serial port is available for Input (pin-26a) is energized to disable Position Control programming and diagnostics. RS485 allows multiple DPR cards Input (pin-28a) is energized to disable Pressure Control to communicate to a host computer, over a single twisted pair Both pin 26a and pin 28a are energized to allow external manual cable. The Rexroth DPR host program runs on a personal control on Input #4 (Version ≥1.04.) Does not affect CNC drive. computer or PC. The DPR host program will automatically detect Force limiting is disabled. the baud rate and find all available DPR stations. Baud rates of 9600, 19200 and 38400 are supported. An RS232 to RS485 converter for COM1 or COM2 is normally required. A serial DPR Menu converter can be ordered separately, Rexroth COM485 Kit (US00 Pushbuttons on the front of the DPR select menu items or adjust 888 281). values. Text can continuously scroll across the 4 digit display. The PC interface is optional since the DPR can be commissioned Parameter values include the decimal point, as needed. When exclusively by using the front display and pushbuttons. negative values are displayed, the minus sign toggles with the Valve Code - All valve parameters are set by Rexroth. The more number. Display values that are positive will not toggle with the common valve settings will be assigned a specific 3-digit code plus sign. Units, like [%], [V], [mV] and [sec] are listed behind the parameter name. The display automatically adjusts for range. In number and stored in the DPR memory. The valve Code is a simple menu option that loads parameters for a valve. More than some cases, the voltage range below 1 volt will be displayed as 0 one code may exist for the same valve. As new designs are to 999 mV. Over 1 volt the range changes to 1.00 to 10.0 V, which introduced, this table will expand without affecting codes for includes the decimal point. existing products. After power is applied, the display includes the UP Increases displayed value, next option at this level abbreviated valve model and driver board that should be DOWN Decreases displayed value, previous option associated with these settings. The Valve Code should also at this level appear on a label on the front panel. ENTER Accept this value or option, move into this All valve parameters are available under “Custom.. ” in the Setup parameter menu. If the default valve settings are changed, the original valve ESC Cancel any change, exit to previous level in menu code will end with a “C”. After power is applied, the display will show “Custom” instead of a valve model. If the DPR had a “C” when Note that some “force” terms in the DPR menu may represent delivered, the original valve Code and custom values are noted on pressure, and vice versa, depending on the specific application. If the Certificate of Conformance. Restore the default parameters by a pressure transducer was replaced by a current transducer setting the desired Code number and removing the “C” with the UP sensing the electric motor, the “force” terms would represent or DOWN push-button. Then press ENTER. power. Parameters that optimize the application are grouped under the Main menu. Press ENTER to see this menu. Some parameters will not appear, depending on the software configuration. Configuration and calibration parameters are hidden under the Setup menu. To call the Setup menu, press both ENTER and ESC for 5 seconds. Then press ENTER to access these options. Password protection is available. 6/12 RA 29 894/06.98 DPR Inputs Jumpers = delivered state J6 –10 V Valve 30a Position/Direct + J6 +10 V V Command Analog 32a - V Input #4 J5 –10 V Valve 14c Position Feedback Driver + J5 +10 V V or CNC Error Analog 12c - V Input #5 (DSN...) I/O (DSF...) (SSF...) J7 –10 V 18c (PSF...) Pressure/Force + J7 +10 V V (SPT...) Feedback 16c Analog - V Input #1 J8 –10 V 18a + Pressure Feedback J8 +10 V V EEPROM 16a Analog Data Input #2 - V 128 x 16 Parameters 24c Pressure/Force –10 V + V Command Analog 22c - V Input #3 Valve Feedback 0 to 5 V 20c RAM Analog Data (if present) (2.5 V = Spool Center) 8K x 8 12a + Tx EPROM Serial Port RS485 14a 32K x 8 - Rx 1K 22a ENABLE 1K UP 1K 24a Auto / AUTO 1K DOWN 1K POSITION 26a –JOG / OFF 1K ENTER 1K 28a PRESSURE +JOG / OFF 1K ESC 10 ~ 35 V (optional) 20a Return 6a Do not change +10 V 20 MHz 6c 10 Ω B -10 V J1 2a 3A 2c B 21 ~ 35 V J2 Power Supply 4a B Position 4c J3 0 V Feedback J4 A or Regulator J3 CNC Drive See next page for valve connections. 7/12 RA 29 894/06.98 Valve connections to DPR 4WRA 4WRAB..DK25 4WRAB…DK25 grd 4WRAB 1 4WRZ 8a 8a a a 2 10a 10a 3 grd 4 8c 8c b b 10c 5 10c 4WRE grd 4WRAEB 8c red/wht b 4a 1 0 V 10c red grd 2a 2 24 V 8a green 3 Ground a 10a red/yel 8a 4 (+) Signal 26c red/blk 10a 5 (–) Signal 1 30c red/blu 8c 6 Enable 2 32c 4WS2EM 4WRTE 4WRTE 8a 2a A 24 V AB 4a B 0 V CD 8c C Enable 10a 8a D (+) Signal 10a E (–) Signal Isolation Valve 8c or 24 VDC relay 32c F Actual 10c (if required) 4WREE 4WRAE 4WRSE 4WRZE 2a A 24 V 2a A 24 V 4a B 0 V 4a B 0 V 4c C (–) Actual C n.c. (0 V) 8a D (+) Signal 8a D (+) Signal 10a E (–) Signal 10a E (–) Signal 32c F (+) Actual F n.c. Do not connect to C or F. 8/12 RA 29 894/06.98 Valve connections to DPR 4WRDE..-5X/..15 4WRD –15 V Power Supply 8a A B A +15 V D C B –15 V 10a C 0 V 8a D (+) Signal D 32c 10a E (–) Signal C 30c 32c F Actual LVDT 8c Isolation Valve E 26c or 24 VDC relay 10c (if required) 24V Isolation Valve 8c or 24 VDC relay 4WRDE..-5X/..24 10c (if required) 2a A 24 V 4WRKE 4WRKE 4a B 0 V 2a A 24 V C 4a B 0 V 8a D (+) Signal 8c C Enable 10a E (–) Signal 8a D (+) Signal 32c F Actual 10a E (–) Signal Isolation Valve 8c or 24 VDC relay 32c F Actual 10c (if required) 9/12 RA 29 894/06.98 Display / adjustment elements 3A 2 FU1 IC12 J1 C J4 B A A B J2 B J3 A J5 J6 J7 J8 32 Additional information – Do not unplug the card while power is being supplied. – Shield analog inputs and valve feedback cables; connect the shield to 0 V or earth ground on one end, leave the other end of shield open. – The mimimum distance to antenna cables, radio sources, and radar systems is 3 ft. (1 meter). – Solenoid and signal cables must not be laid in the vicinity of power cables. Avoid close, parallel runs with AC field wiring, even where separate condiut and shields are used. – The RS485 converter (COM485 Kit US00 888 281) includes a 9/25 pin adapter and 120 V AC wall cube. 10/12 The REXROTH Corporation Bethlehem, PA RA 29 894/06.98 Unit dimensions: dimensions in inches (millimeters) DPR 1.59 (40.3 REXROTH REXROTH Industrial Hydraulics Div. Industrial Hydraulics Div. DPR DNC UP UP DOWN DOWN 3U 5.05 ENTER ENTER (128) ESCAPE ESCAPE 5.05 3.50 3.94 (128) (89) ENABLE (100) ENABLE AUTO -JOG –JOG POS. OFF +JOG 0.59 +JOG PRESS OFF AUX (15) CNC 0.08 (2) 0.28 0.55 8HP (7) (14) 6.77 1.59 (40.3) (172) 7.32 (186) 11/12 RA 29 894/06.98 Notes Mannesmann Rexroth Corporation Rexroth Hydraulics Div., Industrial, 2315 City Line Road, Bethlehem, PA 18017-2131 Tel. (610) 694-8300 Fax: (610) 694-8467 Rexroth Hydraulics Div., Mobile, 1700 Old Mansfield Road, Wooster, OH 44691-0394 Tel. (330) 263-3400 Fax: (330) 263-3333 All rights reserved – Subject to revision 12/12 Printed in U.S.A.