Delta MMC120 User Manual

MMC120

Linear Motion Control Module

Rev 1.00

991221

Delta Computer Systems, Inc.

11719 NE 95th Street, Suite D

Vancouver, WA 98682-2444

Tel: 360/254-8688

Fax: 360/254-5435

http://www.deltacompsys.com

email@deltacompsys.com

Although great effort has been taken to ensure the accuracy ofthe information in this document, it is intended to be used only as a guide. Knowledge of motion control, hydraulic servos, electric servos, magnetostrictive displacement transducers, and safety rules is required. Delta Computer Systems, Inc. cannot accept responsibilityfor problems resulting from omissions in th is document. The information in th is document is subject to change without notice.

Neither Delta Computer Systems, Inc. nor anyone else involved in the creation, production, or delivery of this product shall be liable for any direct, indirect, consequential injuries and or damages arising out of the use, the results of use, or the inability to use this product.

All brand names and trademarks referenced in this manual are the pr operty of their respective holders.

Printed inU.S.A.

Contents

OVERVIEW..................................................................................................................................................9

EATURES................................................................................................................................................9

General...........................................................................................................................................9

Position Inputs................................................................................................................................9

Drive Outputs................................................................................................................................10

SPECIFICATIONS......................................................................................................................................11

EMPERATURE .......................................................................................................................................11

UMIDITY .............................................................................................................................................. 11

IBRATION RESISTANCE......................................................................................................................... 11

HOCK RESISTANCE................................................................................................................................11

MMUNITY .....................................................................................................................................11

ESD I

OWER REQUIREMENTS ..........................................................................................................................11

RANSDUCERINPUTS..............................................................................................................................11

UTPUTS ...............................................................................................................................................11

SOLATION .............................................................................................................................................11

ROTECTION ....................................................................................................................................11

I/O P

GENCY COMPLIANCE............................................................................................................................11

US COMPATIBILITY ............................................................................................................................... 12

AIL SAFE TIMERS..................................................................................................................................12

Drive Output Disable -- 15 microseconds......................................................................................12

Hardware Reset -- 17 milliseconds................................................................................................ 12

DESCRIPTION ...........................................................................................................................................13

RINCIPLE OF OPERATION.......................................................................................................................13

Position Measurement ...................................................................................................................13

Control Loop.................................................................................................................................14

Drive Output.................................................................................................................................15

Quantum Interface........................................................................................................................15

Programming ................................................................................................................................15

Event Control................................................................................................................................15

FLASH Memory............................................................................................................................15

FRONT PANEL INDICATORS ................................................................................................................. 16

SETUPCHECKLIST..................................................................................................................................17

IRING (PAGES 18 AND 19)....................................................................................................................17

NSTALLATION (PAGE 18) .......................................................................................................................17

TART-UP AND TUNING...........................................................................................................................17

PREPARING FOR INSTALLATION........................................................................................................18

IRING NOTES.......................................................................................................................................18

RIVE OUTPUTS .....................................................................................................................................18

AGNETOSTRICTIVE TRANSDUCER WIRING.............................................................................................18

ERIAL PORT.......................................................................................................................................... 20

ONNECTOR INFORMATION ....................................................................................................................20

YDRAULICSYSTEM NOTES ................................................................................................................... 21

STARTUP....................................................................................................................................................22

NITIALIZATION PARAMETERS .................................................................................................................22

SCALE Parameter (Default: 30300) Range: -32767 to 32767, excluding 0...................................23

OFFSET Parameter (Default: 0) Range: -65535 to 65535 position units........................................23

OVING THE AXIS .................................................................................................................................23

Powering Up.................................................................................................................................24

UNING ................................................................................................................................................. 25

OGGING THE AXIS.................................................................................................................................26

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Contents MMC120 Linear Motion Control Module

SAVING PARAMETERS AND PROFILES....................................................................................................... 26

MOTION CONTROL PARAMETERS ..................................................................................................... 27

NITIALIZATION PARAMETERS ................................................................................................................. 27

CONFIGURATION Word (Default: 0000)................................................................................... 27

CONFIGURATION Word Bit Map............................................................................................... 29

SCALE (Default: 30300) Range: -32767 to 32767, excluding 0 .................................................... 30

SCALE Calculation Examples...................................................................................................... 30

OFFSET (Default: 0) .................................................................................................................... 31

EXTEND LIMIT (Defaults to current position on power-up) ........................................................ 31

RETRACT LIMIT (Defaults to current position on power-up) ...................................................... 31

PROPORTIONAL GAIN (Default: 1) Range: 0 to 65535.............................................................. 31

INTEGRAL GAIN (Default: 1) Range: 0 to 65535....................................................................... 32

DIFFERENTIAL GAIN (Default: 0) Range: 0 to 65535................................................................ 32

EXTEND FEED FORWARD (Default: 100) Range: 0 to 65535.................................................... 32

RETRACT FEED FORWARD (Default: 100) Range: 0 to 65535.................................................. 32

EXTEND ACCELERATION FEED FORWARD (Default: 0) Range: 0 to 65535 ......................... 33

RETRACT ACCELERATION FEED FORWARD (Default: 0) Range: 0 to 65535 ....................... 33

DEAD BAND ELIMINATOR (Default: 0) ................................................................................... 33

IN POSITION (Default: 50).......................................................................................................... 33

FOLLOWING ERROR (Default: 250)........................................................................................... 33

AUTOSTOP (Default: 0FFE0 - Soft Stops enabled, Hard Stop enabled........................................ 33

OTION CONTROL COMMANDS.............................................................................................................. 35

MODE (Default: 00000)(See page 36 for the MODE Word bit map)............................................. 35

ACCELERATION (Default: 1000)............................................................................................... 36

MODE Word Bit Map................................................................................................................... 37

DECELERATION (Default: 1000)................................................................................................38

SPEED (Default: 1000)................................................................................................................. 38

COMMAND VALUE ................................................................................................................... 38

COMMAND................................................................................................................................. 38

Move Profiles................................................................................................................................39

MMC120 Initial Move Profiles ..................................................................................................... 40

EADBACK PARAMETERS........................................................................................................................ 41

ACTUAL POSITION.................................................................................................................... 41

AXIS STATUS Word (Seemap on page 42)................................................................................. 41

COMMAND POSITION............................................................................................................... 43

TARGET POSITION.................................................................................................................... 43

TRANSDUCER COUNTS............................................................................................................ 44

ACTUAL SPEED.........................................................................................................................44

DRIVE..........................................................................................................................................44

STATUS Word Bit Map................................................................................................................45

FLASH MEMORY .....................................................................................................................................46

COMMUNICATING WITH THE MMC120............................................................................................. 47

UANTUM BUS CONFIGURATION............................................................................................................. 47

EMORY REQUIREMENTS.......................................................................................................................47

EGISTER OVERVIEW ....................................................................................................................... 48

I/O R

UTPUT REGISTERS................................................................................................................................49

COMMANDS....................................................................................................................................... 49

Command Types........................................................................................................................... 50

Command Type 1 - Go Using Profile (0000 XXXX 0001 NNNN)................................................. 51

Command Type 2 - Set Profiles (0000 XXXX 0010 NNNN)......................................................... 52

Command Type 3 - Set Parameters (0000 XXXX 0011 NNNN).................................................... 54

Command Types 4, 5, 6, and 7 - ASCII Commands (0000 XXXX 01NN NNNN)......................... 55

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MMC120 Linear Motion Control Module Contents

Command Type 9 - Open Loop Using Profile (0000 XXXX 1001 NNNN) ....................................59

Command Type A - Get Profiles (0000 XXXX 1010 NNNN)........................................................ 60

Command Type B - Get Parameters (0000 XXXX 1011 NNNN)................................................... 62

Command Type E - Event Step Edit (0000 XXXX 1110 00NN).................................................... 63

Command Type F - Diagnostics (0000 XXXX 1111 XXXX)......................................................... 63

Extended Command Type E - Event Step Tr ansfer (1110 DSSS SSSS SNNN)............................. 64

NPUT REGISTERS ...................................................................................................................................65

QUANTUM PROGRAMMING HINTS..................................................................................................... 66

RROR HANDLING.................................................................................................................................. 66

TROUBLESHOOTING..............................................................................................................................67

ROBLEMS AND SOLUTIONS ....................................................................................................................67

Ladder program cannot access parameters or operate module........................................................67

Red LEDS 2, 3, 4, 6, 7, or 8 are on................................................................................................67

Red LEDS 2 and 6 are on; all other red LEDS are flashing; no green LEDS on ............................. 67

During a move, the Actual Position is erratic ................................................................................67

During a move, the drive comes to a h alt for no apparent reason...................................................67

Transducer counts field not indicating transducer location ............................................................67

Transducer counts field changes but output drive does not work....................................................67

The System is unr esponsive an d hard to tune ................................................................................ 68

The axis oscillates.........................................................................................................................68

The axis does not finish movesor moves differentlythan expected................................................ 68

HYDRAULIC SYSTEM PROBLEMS.......................................................................................................69

ONLINEAR VALVES...............................................................................................................................69

LOW-RESPONSEVALVES .......................................................................................................................69

OSES....................................................................................................................................................69

UMPS AND ACCUMULATORS .................................................................................................................. 70

DENTIFICATION AND CORRECTION ......................................................................................................... 70

REPAIRS AND RETURNS......................................................................................................................... 73

ARRANTY ........................................................................................................................................... 73

ODULE RETURN FOR REPAIR ................................................................................................................ 73

ETURNS ...............................................................................................................................................73

ELTA BULLETIN BOARD SYSTEM....................................................... ERROR!BOOKMARKNOT DEFINED.

ELTA WEB PAGE AND EMAIL ................................................................................................................73

GLOSSARY OF TERMS............................................................................................................................74

ASCII TABLE.............................................................................................................................................75

APPENDIX A: DCS120 DIAGNOSTIC AND SETUP PROGRAM.......................................................... 76

ESCRIPTION ......................................................................................................................................... 76

ENERAL FEATURES...............................................................................................................................76

NITIAL STARTUP USING DISPLAY-ONLY MODE .......................................................................................77

NITIAL STARTUP USING MOTION CONTROL MODULE..............................................................................79

HE DCS120 SCREEN ............................................................................................................................80

Read Only Parameters...................................................................................................................80

Command Parameters...................................................................................................................80

Input Field....................................................................................................................................80

Initialization Parameters...............................................................................................................80

Command Queue ..........................................................................................................................80

UMMARY OF KEYBOARD COMMANDS ....................................................................................................81

IAGNOSTIC GRAPHS..............................................................................................................................83

EYBOARD COMMANDS .........................................................................................................................84

Getting Help .................................................................................................................................84

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Contents MMC120 Linear Motion Control Module

Function Keys............................................................................................................................... 84

Exiting DCS120 Screens...............................................................................................................84

Displayin g Axis Status Information .............................................................................................. 84

Editing the .INI File......................................................................................................................84

Motion Control Commands...........................................................................................................84

Open Loop Command................................................................................................................... 85

Readback and Write Mode Toggle ................................................................................................ 85

SCALE & OFFSET Calculation Commands................................................................................. 85

OFFSET Parameter....................................................................................................................... 85

ARIABLE DATALOGGING RATES............................................................................................................85

OVING AXES SIMULTANEOUSLY........................................................................................................... 86

ABLE EDITORS ..................................................................................................................................... 86

DVANCED FEATURES............................................................................................................................ 87

DOS Command Line Options....................................................................................................... 87

ETTINGUP ADVANCED FEATURES ......................................................................................................... 87

ESCRIPTION OF INITIALIZATION FILE AND PROJECT FILES....................................................................... 87

Initialization File.......................................................................................................................... 88

Project Files.................................................................................................................................. 90

SER NOTES .......................................................................................................................................... 93

Negative Offset............................................................................................................................. 93

ViewData Command....................................................................................................................93

Sum of Errors Squared (ÿÿÿÿe

MMC120 Communication Cable...................................................................................................94

)......................................................................................................... 93

APPENDIX B: EVENT CONTROL........................................................................................................... 95

NTRODUCTION ...................................................................................................................................... 95

VERVIEW............................................................................................................................................. 95

TEPS....................................................................................................................................................95

Commands.................................................................................................................................... 95

Link Word.................................................................................................................................... 95

Step Table..................................................................................................................................... 96

INKING STEPS.......................................................................................................................................97

Link Next..................................................................................................................................... 97

Link Type and Link Value............................................................................................................97

TEPEXECUTION ................................................................................................................................... 99

Example ..................................................................................................................................... 100

TARTING A SEQUENCE ........................................................................................................................ 100

Triggering Events ....................................................................................................................... 100

Ending a sequence...................................................................................................................... 100

SING DCS120.................................................................................................................................... 101

Accessing the DCS120 Step Editor screen................................................................................... 101

Step Editor Commands............................................................................................................... 101

Reading Step files from disk and module.................................................................................... 102

Sending Step files to disk, module, and Flash memory ................................................................ 102

OTES................................................................................................................................................. 103

Reading the Current Step............................................................................................................ 103

Terminating a Loop.................................................................................................................... 103

Interrupting a Sequence.............................................................................................................. 103

Multiple Axes Can Use th e Same Steps....................................................................................... 103

No Conditional Branching.......................................................................................................... 103

INDEX ....................................................................................................................................................... 104

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MMC120 Linear Motion Control Module Overview

OVERVIEW

The MMC120 Motion Control Module is a complete two-axis position control subsystem for the Modicon TSX Quantum Automation Seriesfamilyof Programmable Controllers. An onboard pr ocessor controls the axes, providing complete independent PID motion control loops and allowing on-the-flymotion profile chan ges. The module h as two opticallyisolated magnetostrictive tr ansducer interfaces and twoopticallyisolated ±10 volt outputs.

The MMC120 occupies one slot of the Quantum rack. The MMC120 and the Programmable Contr oller communicate over the backplane through four output and four input registers. The onboard 80C188EB 20MHz processor relieves the Programmable Controller of the overhead n eeded for servo control. The Motion Control Module updates the axis position and drive output 1000 times each second, assuring precise positioning even at high speeds.

If more than two axes of control are needed, additional MMC120 modules can be installed.

Features

General

• Modicon TSX Quantum Automation Seriescompatible (ModConnectCertified)

• Uses one slot of Quantum rack

• Hot swappable

• Linear position control

• 80C188EB processor operating at 20 MHz

• 1 millisecond control loop time

• Magnetostrictive Transducer Interface

• Maximum velocity in excess of 120 inches per second

• Maximum transducer length greater than 220 inches

• Hardware fail safe timers

• FLASHmemoryfor parameter and profile storage

• Software configurable -- no jumpers or switches

• Diagnostic and tuning software included

Position Inputs

• Two optically isolated magnetostrictive transducer interfaces

• Differential or single-ended signal compatibility

• Start/Stop or Pulse Width Modulated signal compatibility

• 120 MHz count rate -- counting both edges of a 60 MHz clock

• 1 circulation

• Position resolution better than 0.001 of an inch

Modicon, ModConnect and TSX Quantum Automation Series are registered tr ademarks ofSchneider

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Overview MMC120 Linear Motion Control Module

Drive Outputs

• Two optically isolated ±10 volt outputs

• 12 bit digital-to-analog converters

• Current output available with VC2100 voltage-to-current option

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MMC120 Linear Motion Control Module Overview

SPECIFICATIONS

Temperature

Operating: 0oCto+60oC Storage: -40oCto+85oC

Humidity

93% non-condensing

Vibration Resistance

1gat60Hzto500Hzfor23minutes

0.075 mm displacement from 10 Hz to 60 Hz

Shock Resistance

30 g for 11 milliseconds

ESD Immunity

8kV

Power Requirements

+5V @ 1 Amp from the backplane

Transducer Inputs

Direct in terface to magnetostrictive transducers Differential or single-ended transducer compatibility Start/Stop pulses or Pulse Width Modulated signals

Outputs

±10 volts into 2000 Ohm or greater load -- current output is available with the optional VC2100 voltage-tocurrent converter

Isolation

All inputs a nd outputs used for control purposes are optically isolated from the module, with 2500VDC withstand voltage

Each input an d output section is isolated from the other sections The RS-232 port is not isolated

I/O Protection

All inputs and outputs are protected against transients by clamp diodes

Agency Compliance

UL, CSA, and CE

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Overview MMC120 Linear Motion Control Module

Bus Compatibility

ModConnect® Certified partners Quantum Automation Series Direct connection to Quantum backplane 4 input and 4 output registers, using 64 input and 64 output points 32 registers for parameter storage (16 per axis) 32 registers maximum for profile storage (16 per axis) 2048 registers maximum for event steps (256 steps)

Fail Safe Timers

The MMC120 has two fail safe timers:

Drive Output Disable -- 15 microseconds

The fastest fail safe timer on the MMC120 is 15 microseconds long and is retriggered by activity on th e module's internal bus. If the timer is not r etriggered within 15 microseconds, it disables the dr ive outputs. When internal bus activityresumes, the driveoutputs are re-enabled.

Hardware Reset -- 17 milliseconds

If the microprocessor fails to retrigger the onboard watchdog timer, the 17 millisecond h ardware reset timer expires and resets the hardware. This has the same effect on the MMC120 as powering up. While the module is being reset, the Fail LED on the front panel is illuminated.

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MMC120 Linear Motion Control Module Description

DESCRIPTION

Principle Of Operation

Position Measurement

The MMC120 has interface circuitry for twomagnetostrictive transducers. Each axis can be configured for a Start/Stop transducer or a Pulse Width Modulated transducer by changin g the axis' Configuration Word. To make a measurement with a Start/Stop transducer, the MMC120 sends an interrogation pulse to the transducer. The transducer responds byreturning 2 pulses -- a 'Start' pulse and a 'Stop' pulse. The counters on the MMC120 are active between the two pulses. The time between the pulses is proportional to the transducer position.

Interrogation Pulse

Start Pulse

Counters Active

Start/Stop Pulse Transducer

To make a measurement with a Pulse Width Modulated transducer, the MMC120 sends an interrogation pulse to the transducer. The transducer responds with a return signal th at is high while the transducer is determining its position. The counters on the MMC120 are active while the return signa l is high. The width of the return signal is pr oportional to the transducer position.

Interrogation Pulse

Return Signal

Counters Active

Pulse Width Modulated T ransducer

Stop Pulse

While the counters on the MMC120 are active, they count the number of half-cycles of a 60 MHz clock (120 MHz effective rate). At this frequency, each half-cycle represents less than 0.001 inch displacement of the axis.

The MMC120 converts the Transducer Counts read from the counters to an ACTUAL POSITION in userdefined Position Units (usually 0.001 inch) for use by the Quantum Programmable Controller.

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Description MMC120 Linear Motion Control Module

Position

Control Loop

The MMC120 is a targeting controller; each millisecond the onboard microprocessor updates the TARGET POSITION and target speed values. For point-to-point moves, TARGET POSITIONS are generated so the target speed follows a profile. The MODE, ACCELERATION, DECELERATION, SPEED, and COMMAND VALUE (requested position) are used to generate the profile. They are specified bythe user, and can be changed while th e axis is moving.

Maximum Speed

Speed

Acceleration Ramp

Deceleration Ramp

Time

The ACTUAL POSITION measured by the magnetostrictive transducer is compared with the TARGET POSITION to determine the position error. Every millisecond the position error is used to calculate th e closed loop components of the drive output. It is multiplied by the PROPORTIONAL GAIN to calculate the proportional component of the drive output. The accumulated position err or is used, along with the INTEGRAL GAIN, to calculate the integral portion of the drive output. The change in position error, along with the DIFFERENTIAL GAIN, is used to calculate th e differential portion of the drive output.

Actual

Position

Error Proportional

Gain

Integral

Gain

Differential

Gain

Drive

Output

Target

Position

Accumulator

(Integrator)

∆

∆ Error

∆ ∆

(Differentiator)

Position∆∆∆∆

(Velocity)

Velocity

∆∆∆∆

Target

Generator

Command Processor

Ladder

Logic

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DCS120

(Acceleration)

Feed

Forward

Accel Feed

Forward

Deadband

Eliminator

MMC120 Linear Motion Control Module Description

In addition to the closed loop drive, the MMC120 has two feed forward terms, made up of EXTEND and RETRACT FEED FORWARD, and EXTEND and RETRACT ACCELERATION FEED FORWARD. These feed forward terms give approximatelythe drive needed to make the axis followthe target, freeing the PID loop to correct for nonlinearity in the system and changes in system load.

Drive Output

The drive generated by the MMC120 is sent through optical isolation to a 12 bit digital-to-analog converter (DAC). Th e output from the DAC is amplified to providea ±10 volt output to th e hydraulic valve. Servo valves that need current input require a voltage-to-current converter (Delta par t number VC2100). Proportional valves work directlywith the voltage signal.

Quantum Interface

The MMC120 communicates with the Quantum controller over the backplane. The module is I/O mapped as a DCS MMC 120 0x with four input and four output registers. Commands and status for both axes are transferred across the backplane in groups of four 16-bit words.

Programming

Commands to the MMC120 are sent by writing to the Programmable Controller's output registers. The first two registers send commands to axis 1 while the n ext two registers send commands to axis 2. Programming details ar e presented in the section "COMMUNICATING WITH THE MMC120."

Event Control

Sequences of commands can be stored and executed by the MMC120 with little in tervention by the Programmable Controller. This allows a 1 millisecond response time by the MMC120 to internal events such as move done or elapsed time.

FLASH Memory

You can store parameters, profiles, and Event Control steps in the MMC120's non-volatile FLASH Memory. This reduces th e memory requirements in the ProgrammableController and eliminates the need to tran sfer initialization parameters back and forth.

NOTE: Since data is stored in the module, when you replace one module with another you must transfer the

parameters and profiles to the n ew module . Because of this, you must store all par ameters an d profiles either in the ladder logic program or in a DCS120 file so they can betransferred to a module when needed.

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Front Panel Indicators MMC120 Linear Motion Control Module

FRONT PANEL INDICATORS

There are 14 green and red light emitting diodes (LEDS) on the front panel of the MMC120. These LEDS providestatus information about the module and each of the two axes.

The LED labeled "F" is the FAIL indicator for the MMC120 microprocessor. If the FAIL indicator is red, the drive outputs are disabled an d the axes will n ot move unless the valveis out of null.

The LED labeled "Active" indicates the status of communications over the backplane. When th is LED is green, communication is normal. When it is off, communication has stopped.

The numbered LEDS indicate the status of the axes.

NOTE: Thereare three transducer errors: No Transducer, Transducer Noise, and Transducer Overflow. The default

AUTO STOP settings will make any of these errors cause a Hard Stop, set the output of the axis to the current drive null, an d turn on its red LED. Once the transducer error h as been corrected, a new command to the axis will turn the red LED off.

Fail indicator constant red Onboard processor halted; drive

outputs disabled

Active indicator off Communication disabled Active indicator green Communication OK

Green LED 1 Axis 1 Parameters Initialized Green LED 2 Axis 1 Transducer OK Greed LED 5 Axis 2 Parameters Initialized Green LED 6 Axis 2 Transducer OK Red LED 1 (Emergency Stop) Axis 1 Hard Stop/Open Loop Red LED 2 (No MDT) Axis 1 No Transducer Red LED 3 (Noise) Axis 1 Transducer Noise Red LED 4 (Overflow) Axis 1 Transducer Overflow Red LED 5 (Emergency Stop) Axis 2 Hard Stop/Open Loop Red LED 6 (No MDT) Axis 2 No Transducer Red LED 7 (Noise) Axis 2 Transducer Noise Red LED 8 (Overflow) Axis 2 Transducer Overflow

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MMC120 Linear Motion Control Module Setup Checklist

SETUP CHECKLIST

Wiring (Pages 18 and 19)

Wire magnetostrictive transducers to 9-pin terminal block on MMC120. See your transducer documentation for connector pinout or cable color codeinformation.

Wire MMC120 drive outputs (3-pin terminal block) to actuators (+out = axis extends) Install and connect power supplies needed for your transducers

Installation (Page 18)

Define input and output registers I/O Map the MMC120 (DCS MMC 120 0x, 4 input registers, 4 output registers) Reserve memory for the module (parameters, profiles, event steps)

Start-up and Tuning

Run DCS120 setup program Configure MMC120 to match transducers (See Configuration Word, bits 1-4onpage25) Set Extend and Retract Limits Tune the axes Save parameters in DCS120 to a .BD1 file (S filename command - page 78) Save parameters to Flash memory (page 43) Read parameters and profiles into Programmable Controller

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Preparing For Installation MMC120 Linear Motion Control Module

PREPARING FOR INSTALLATION

Wiring Notes

Useshielded twisted pairs for all connections to in puts and outputs. Route the tr ansducer wiring separate from other wiring.

You must provide the power supplies needed for your transducers.

Drive Outputs

When wiring the system, it is important that the drive extends and tr ansducer counts increase when a positive voltage is sent to the drive. The extend direction is defined as the direction that causes the transducer to return increasing counts. The extend direction of a magnetostrictivetransducer is away from the head.

Magnetostrictive Transducer Wiring

NOTE: The following example schematics do not include transducer pin numbers, color codes, or power supply

requirements, since these vary among different transducers. To determine your power supply needs and connector pinouts or cable color codes, consult your transducer documentation.

The MMC120 can interfaceto transducers with either single-ended (TTL) or Differential Line Driver (RS-

422) interrogation and return signals. With RS-422 signals, connect both the '+Int' and '-Int' between the transducer and the MMC120 for the interrogation signal, and connect both the '+Ret' and '-Ret' between the transducer and the MMC120 for the return signal. Connect the transducer DC ground to MDT Common.

For single-ended transducer with positiveinterrogation, connect th e transducer '- interrogation in' wire to the MDT Common pin and the tran sducer '+ interrogation in' wire to the '+ Int' pin. CONNECT NOTHING TO THE '- INT' PIN OF THE MMC120. Connect the transducer return plus wire to the '+' return pin on the MMC120 and the transducer return common wire to MDT Common on the MMC120. CONNECT NOTHING TO THE '- RETURN' PIN OF THE MMC120.

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MMC120 Linear Motion Control Module Preparing For Installation

Temposonics I transducer users:

For the negative in terr ogation version of this transducer, connect the transducer '+ interrogation in' wire to the MDT Common pin and the tran sducer '- interrogation in' wire to the '- Int' pin. CONNECT NOTHING TO THE '+ INT' PIN OF THE MMC120. Connect the transducer return plus wire to the '+' return pin on the MMC120 and the transducer return common wire to MDT Common on the MMC120. CONNECT NOTHING TO THE '- RETURN' PIN OF THE MMC120.

Some Temposonics I transducers from MTS have 200 Ohm termination resistors installed between their interrogation pins and common. If yours do not, it maybe necessaryto install them as close to the transducers as possible to reduce electrical noise in the system.

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Preparing For Installation MMC120 Linear Motion Control Module

Serial Port

The communication cable attached to th e serial port is a potential source of electromagnetic radiation from the MMC120. To minimize radiation, use a well-shielded cable which is as sh ort as possible. Route it out the bottom of the module and against the back panel.

Connector Information

Transducer interface: Nine Pin Plug-in Terminal Block

Pin Function

1 Axis 1 + Interrogation 2 Axis 1 - Interrogation 3 Axis 1 + Return 4 Axis 1 - Return 5 MDT Common 6 Axis 2 + Interrogation 7 Axis 2 - Interrogation 8 Axis 2 + Return 9 Axis 2 - Return

NOTE: The tran sducer interface can be used with either differential (RS-422) or single-ended (TTL) transducer

signals. For an RS-422 transducer, connect both the '+Int' and '-Int' between the transducer and the MMC120 for the interrogate signal, and connect both the '+Ret' and '-Ret' between the transducer and the MMC120 for the return signal. Connect the transducer DC ground to MDT Common.

For a positiveinterrogation, single-ended transducer, connect the transducer '- interr ogation in' wire to the MDT Common pin and the tran sducer '+ interrogation in' wire to the '+ Int' pin. CONNECT NOTHING TO THE '- INT' PIN OF THE MMC120. Connect the transducer return plus wire to the '+' return pin on the MMC120 and the transducer return common wire to MDT Common on the MMC120. CONNECT NOTHING TO THE '- RETURN' PIN OF THE MMC120.

For a negative interrogation, single-ended transducer, connect the tr ansducer '+ interrogation in' wire to the MDT Common pin and the tran sducer '- interrogation in' wire to the '- Int' pin. CONNECT NOTHING TO THE '+ INT' PIN OF THE MMC120. Connect the transducer return plus wire to the '+' return pin on the MMC120 and the transducer return common wire to MDT Common on the MMC120. CONNECT NOTHING TO THE '- RETURN' PIN OF THE MMC120.

Drive Output: Three Pin Plug-in Terminal Block

Pin Function

1 Axis 1 Drive 2 Drive Common 3 Axis 2 Drive

Serial Port:DB-9

Pin Function

2 Receive 3 Transmit 5 Common

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MMC120 Linear Motion Control Module Preparing For Installation

Hydraulic System Notes

Hydraulic systems must have enough pressure and fluid volume (accumulator) to move the desired load the commanded distance at the commanded speed. Inadequate pressure or volume will cause the axis to lag the target position as the controller attempts to move the axis faster than the system can move.

There should be no flexible h ose between the valveand th e cylin der being controlled. Hose swells and contracts as th e valve opens and closes, causing oscillation and loss of control.

If pr oportional valves are used they should h ave zero overlap an d a linear (not curvilinear) response. Overlapped or nonlinear valves may cause oscillation or hunting.

Valves with slow response cause the Motion Control Module(MCM) to overcompensate for disturbances in the motion of the system. With a slow value the system will n ot respond immediatelyto the control signal, so the MCM continues to increase the drive signal. By the time the system begins to respond to the error, th e control signal has become too large and the system overshoots. The MCM then attempts to control in the opposite direction, but again it overshoots. These valves can causethe system to oscillate around th e set point as the MCM overshoots first in one dir ection, then the other.

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Startup MMC120 Linear Motion Control Module

STARTUP

CAUTION: Do not connect the drive outputs to the drives un til the EXTEND and RETRACT limits have been

determined and the MMC120 has been properly initialized with these limits by the Quantum ProgrammableController.

Great care must be taken to avoid accidents when starting the Motion Control Module for the first time. The most common accident is a r un away, where th e motion controller tr ies to go to a position beyond the physical limits of an axis.

When the MMC120 Motion Control Module is first turned on the parameters are set to default values. These values allow th e module to maintain the pr esent positions of the axes it controls; the parameters must be changed for the module to work in your system. The Quantum Programmable Controller program is responsible for initializing the parameters when the MMC120 is powered up by sending the correct initialization parameters to the module, then issuing a 'P' command. The following procedure will help find the optimum values for the initialization parameters.

TIP: Use Delta's DCS120 setup program to help determine initial parameters an d operation. Also, Delta's SSS/10

ServoSystem Simulator and PPS/14 Position/Pressure Simulator provide a simple wayto test your program before connecting the module to a real system. See APPENDIX A: DCS120 DIAGNOSTIC AND SETUP PROGRAM.

Configure DCS120 to communicate with the module. Make sure the transducers are connected and powered up. Disconnect the drive output from the MMC120 (3 pin connector), and arrange a wayto manually move the axis, either physicallyor with a control box that can electrically drive the valve (a 'diddle box'). If neither of these options are usable to you, the procedure shown in 'Moving the Axis' (pages 21 and 22) uses DCS120 and the Open Loop mode to slowlymovethe axis.

Initialization Parameters

If you want to get started quickly, go to the next section - Moving The Axis. Continue with this section now or return to it later to set the SCALE and OFFSET parameters.

The easiest way to set the SCALE and OFFSET is to use the P0 and P1 commands in DCS120. To use these commands, you n eed to know the physical position and the corresponding transducer counts at two points (usuallythe extend and r etract limits). For example, if the first position is 0.000 inches and the counts are 2163, and the second position is 27.500 inches and t he counts are 31626, then enter:

P0 0 2163 <ENTER> P1 27500 31626 <ENTER>

After you enter values for bo th P0 and P1, the SCALE and OFFSET fields will be updated on the screen (notice the parameters turn gray). Use the alt-P command to activate th e newvalues. See Appendix A for more information about the P0 and P1 commands.

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MMC120 Linear Motion Control Module Startup

SCALE Parameter (Defaul t: 30300) Range: -32767 to 32767, excluding 0

The SCALE factor converts TRANSDUCER COUNTS to Position Units. The SCALE is defined as:

Position Units per Inch x 32768

SCALE =  xSign

Transducer Cal. Number (µs/in.) x 120 MHz

Where 'Sign' equals +1 when an extend move yields increasing ACTUAL POSITION, and -1 when an extend move yields decreasing ACTUAL POSITION. An extend move always y ields increasing TRANSDUCER COUNTS, but the sign of SCALE determines whether extending the axis will give increasing or decreasing ACTUAL POSITION.

The calibration number must be specified in the same base units as the Position Units (inches, mm, etc.). Position Units are generally 0.001 inches or 0.1 mm. There are usually1000 Position Units per inch when the calibration number is in microseconds per in ch.

OFFSET Parameter (Default: 0) Range: -65535 to 65535 position units

Next, the axis OFFSET must be set. The axis OFFSET is added to the position of the axis when the ACTUAL POSITION is computed. When the OFFSET is changed make sure to change the EXTEND LIMIT and RETRACT LIMIT by the same amount. Use the following equation to adjust the current ACTUAL POSITION to be something else:

OFFSET = old OFFSET + DESIRED POSITION - ACTUAL POSITION

Both th e EXTEND and RETRACT limits must be adjusted in the same way as the OFFSET, and another 'AltP' command must be issued. Move the axis to the EXTEND and RETRACT limits and make an y adjustments necessary.

MAXIMUM COUNTS

65,535

-60,423

-35,423

TRANSDUCER COUNTS

SCALE = -30,212

OFFSET = 25,000

EXTEND & RETRACT LIMITS

RETRACT LIMIT= 20,000

25,000

ROD LENGTH

39,046

-36,000

-11,000

EXTEND LIMIT = -6,000

Moving The Axis

With the axis drive output still disconnected and the transducer on, move the axis close to the ph ysical extend limit (move it either man ually or with a 'diddle box') - be sure to leave some space for safety. If neither of these movement options are usable to you, the following procedure uses DCS120 and the Open Loop mode to slowly move the axis. (Remember: extending is the direction that returns increasing TRANSDUCER COUNTS.)

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Startup MMC120 Linear Motion Control Module

Open Loop Procedure

CAUTION - OPEN LOOP OPERATION IGNORES ALL LIMITS! BE PREPARED TO REMOVE DRIVE

POWER!

A. Connect the MMC120 drive output to the valves. B. In DCS120, with the cursor on the axis you want to adjust, enter Alt-R to restore the null. Put 0 (zero)

in the COMMAND VALUE field, enter Alt-Shift-O, and verify that DRIVE = 0. If the NUL L DRIVE

is not zero, enter Alt-N to zero it. C. Turn on the hydraulics (the axis will drift due to valve null errors). D. Put 500 in the COMMAND VALUE field and enter Alt-Shift-O, then put 0 (zero)in the COMMAND

VALUE field. Verify that DRIVE = 500. The axis should extend. If the axis retracts, check the drive

wiring polarity, hydraulic plumbing, and the value null. Correct any pr oblems before continuing. E. When the axis gets to the extend limit, enter Alt-Shift-O, then Alt-P to stop the axis. Enter the

ACTUAL POS. value in the EXTEND LIMIT parameter. F. Put -500 in the COMMAND VALUE field and enter Alt-Shift-O, then put 0 (zero) in the COMMAND

VALUE field. Verifythat DRIVE = -500. The axis should retract. G. When the axis gets to the retract limit, enter Alt-Shift-O, then Alt-P to stop th e axis. Enter the

ACTUAL POS. value in the RETRACT LIMIT parameter. H. Repeat Steps B through G for each axis in use.

Enter the ACTUAL POSITION reading as the value fo r the EXTEND LIMIT parameter. Now move the axis close to the physical retract limit and set the RETRACT LIMIT parameter. Issue an 'alt-P' command. (If you are using DCS120, be sure to read the parameters in to the Programmable Controller's memory using Command Type B.)

Powering Up

CAUTION: If the outputs from the MMC120 are reversed, the axis will be uncontrollable when power is connected. Confirm that your wiring is correct!

NOTE: To input hexadecimal numbers to DCS120, enter a zero as the first character: 0FFFF

Turn off the power to the MMC120 and connect the drive output. Turn the power back on and issue a 'P' command on both axes. Set the MODE to 00000, and the SPEED, ACCELERATION, and DECELERATION to about 20% of the expected maximum speed. To confirm that everything is correct, make some short moves by entering the COMMAND VALUE and issuing a GO ('G') command.

NOTE: DCS120 is extremely useful; we recommend you use it to configure, tune, and troubleshoot the system.

Refer to Appendix A for information about creating plots of moves.

At this point AUTO STOP should be set to 0E0E0 so any transducer error on an axis will cause it to stop, but other errors will not. Check the STATUS word for errors after each move.

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MMC120 Linear Motion Control Module Startup

Tuning

There is no substitute for experience when tuning an axis. This section offers some guidelines, tips, and suggestions for tuning your system. While these steps will work for many systems, they may not be the best for a particular system.

In many hydraulic systems the feed forward parameters (EXTEND FEED FORWARD and RETRACT FEED FORWARD) are the most important par ameters for position tracking during a move. One way to adjust these parameters is to set the DIFFERENTIAL GAIN and INTEGRAL GAIN to zero and the PROPORTIONAL GAIN to a small value (between 1 and 5), then make long slow moves in both directions. Adjust the EXT FEED FORWARD and RET FEED FORWARD until the axis tracks within 10% in both directions. In hydraulic systems, the EXTEND and RETRACT FEED FORWARD terms will differ by the ratio of the extend and retract piston areas.

Alternately, you can find th e appropriate value for the FEED FORWARD terms by making moves with the axis at a SPEED of 1,000. The amount of output drive required to maintain this SPEED is the correct value for th e FEED FORWARD par ameter.

A third approach is to use the 'alt-F' command. This command, used after a move without oscillation or overdrive on an axis, will automaticallyadjust the FEED FORWARD parameter for th e direction of that move. See Appendix A for more information.

PROPORTIONAL GAIN affects the responsiveness of the system. Low gains make the sy stem sluggish and unresponsive. Gains th at are too high make the axis oscillate or vibrate. You can adjust the PROPORTIONAL GAIN by slowly increasing it and moving the axis. When yo u see a tendency to oscillate as the axis moves or stops, reduce the gain by10 to 30 percent.

Many hydraulic systems do n ot require INTEGRAL GAIN or DIFFERENTIAL GAIN. However, it is usually desirableto have some INTEGRAL GAIN (5 to 50 counts) to help compensate for valve null drift or changes in system dynamics. Some systems may require larger INTEGRAL GAIN, in particular if theyare moving a large mass or are n onlinear. Too much INTEGRAL GAIN will cause oscillations.

DIFFERENTIALGAIN is used mainly on systems which have a tendency to oscillate. This happens when heavyloads ar e moved with r elatively small cylinders. DIFFERENTIAL GAIN will tend to dampen out oscillations and help th e axis track during acceleration and deceleration. If you use DIFFERENTIAL GAIN, you may be able to increase the PROPORTIONAL GAIN somewhat without causing the system to oscillate.

A disadvantage to DIFFERENTIAL GAIN is th at it amplifies position measurement noise which can cause the system to chatter or oscillate if the gain is toohigh or there is toomuch noise.

The ACCELERATION FEED FORWARD terms are particularly useful for axes which move large masses with relativelysmall cylinders. This combination delays the start of movement, and the ACCELERATION FEED FORWARD terms can h elp compensate for this delay. ACCELERATION FEED FORWARDS ar e easiest to adjust with the PID gains set low and the VELOCITY FEED FORWARDS adjusted properly. After commanding a move, plot the move using DCS120 and look for a following error during the acceleration. Increase the ACCELERATION FEED FORWARD until the error disappears. For large masses the ACCELERATION FEED FORWARD can be in the tens of thousands.

If the axis hunts around the set point, you can increase the DEAD BAND ELIMINATOR value slowly until the hunting stops or the axis starts to oscillate. If it oscillates, reduce the DEAD BAND ELIMINATOR value.

If the axis gets no fo llow ing errors, reduce the MAXIMUM ERROR until errors start to occur then adjust the FEED FORWARD gains.

Increase the SPEED and ACCELERATION values gradually while making long moves. Use DCS120 to plot the moves and look for following errors, overshoot, or oscillations. Eventually, when the SPEED an d ACCELERATIONS are too high, the moves will cause an error on the axis.

If an overdrive err or occurs, th ere is not enough drive capacity to drive the axis at the requested SPEED. Should th is occur, reduce the SPEED. If a following error occurs, the appropriate FEED FORWARD must be

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Startup MMC120 Linear Motion Control Module

increased. If the FOLLOWING ERROR occurs on an extend move, increase the EXTEND FEED FORWARD; it the error occurs on a retractmove, increasethe RETRACT REED FORWARD. If this doesn't solve the problem, the ACCELERATION and DECELERATION ramps are too steep for the response of the system. Their values can be reduced, or the ACCEL FEED FORWARD and DECEL FEED FORWARD terms can be increased. After the problem which caused the error has been corrected, keep moving the axis back and forth with in creasing speed until you r each the desired speed. Should the system seem a little sloppy, try decreasing the MAXIMUM ERROR and adjusting the PROPORTIONAL GAIN until the axis can be moved without getting an error. Remember: the parameters are not updated in the MMC120 until th e 'P' command is issued.

Jogging The Axis

You can jog the axis by setting th e COMMAND VALUE to the EXTEND LIMIT or RETRACT LIMIT and using the 'G' an d 'H' commands repeatedly. This causes the Motion Control Module to GO and HALT.

Saving Parameters and Profiles

After the system is set up and tuned using DCS120, you need to store the parameter and profile values in the ProgrammableController. Th is is done using Command Types A and B. Only the parameters for the axes used need to be saved, and only the profiles used need to be saved.

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MMC120 Linear Motion Control Module Motion Control Parameters

MOTION CONTROL PARAMETERS

Sixteen Parameter registers and 6 Command registers control the operation of the MMC120. The status of the module is shown in 10 in tern al Readback registers. Manipulating the contents of the Parameter and Command registers is key to the successful application of the MMC120.

Delta's DCS120 program (included with the module) gives you direct access to all the internal registers. This is helpful for setup and debugging.

The chapter ' Communicating With The MMC120' describes howthe Quantum Programmable Controller gains access to the internal registers of the MMC120. This chapter describes these internal registers.

Initialization Parameters

CONFIGURATION Word (Default: 0000)

Eleven bits of this 16-bit word control the configuration of the module. Bit 16 is the LSB; bit 1 is the MSB.

Bits1-4-Transducer Type bits

Set these bits all to 0 if the transducer is start-stop. If the transducer is gated, set the bits so the value of th ese four bits equals the number of recirculations the gated tran sducer is set to (bit 1 = 8, bit 2 = 4, bit 3 = 2, and bit 4 = 1). For example, if the transducer is set to one recirculation, bit 4 should be set. If the transducer is set to 10 recirculations, bits 1 an d 3 should be set, and if it is set for 15 recirculations, all four bits should be set to 1.

When a transducer is set for multiple recirculations, there is a small time delay between those recirculations. During th is time the counter on the MMC120 continues to count, resulting in about 2700 extra counts per recirculation which are added to the transducer count. These extra counts create an offset; to correct this offset the module calculates the extra counts based on the number of transducer recirculations and subtracts them from th e transducer count. If the value of these bits and the transducer recirculations agree, the transducer count should be slightly positive when the transducer is at its minimum position. If your minimum position count is negative, reduce the setting of these bits until the count is slightly positive.

If you are using a gated transducer and want resolution better than 0.001 inches, we suggest using 10 recirculations an d setting bits 1 and 3. This will give 0.0001 inch resolution with a stroke of about 6.5 inches.

Bit 10 - Reverse Drive Mode bit

When this bit is set the polarityof the axis’ output voltage is reversed. This bit is useful when you are connected to two drives which do not have differential or isolated inputs, and you need one to extend with positive dr ive and the other to extend with negative dr ive. (If the drives have differential or isolated inputs, you can just reverse the connections to th e drivethat must extend with negative drive.) When this bit is set, transducer counts will DECREASE with positive drive and the displayed drive will be the opposite of what is output by the module (a positive display will output a negative voltage).

Bit 11 - Absolute Mode bit

This mode is intended for use with a two-valve system, one controlling the flow rate and the other the direction. This axis controls the flow rate valve. The directional valve must be controlled by other means. In this mode, the axis generates a positive drive output regardless of th e direction of the move. The drive will not

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Motion Control Parameters MMC120 Linear Motion Control Module

go negative if the motion controller overshoots the target. This is useful for some injection and blow-molding applications. When this bit is set, two chan ges are made to the way Open Loop mode is used:

1) After completing a move the axis is automatically placed in Open Loop mode with the dr ive set to null.

2) When a “P” command is sent to the axis, it is placed in Open Loop mode with th e driveset to null.

Bit 12 - Continue Mode bit

This bit affects what happens when the module loses contact with the PLC. When this bit is set, the module will finish any move it has started; otherwise it will halt immediately upon detecting loss of contact with th e PLC. This is useful for finishing a move which must complete to prevent th e machine from stopping in an incomplete state (for example, a partial shot in an injection molding machine).

Bit13-Simulatebit

When this bit is set, the drive output is set to null and the magnetostrictivetransducer inputs are ignored. Internally the TARGET POSITION is used as the ACTUAL POSITION. This mode is used for debugging. (The transducer error bits and LEDS will be cleared.)

Bit 14 - Divide by 4

When this bit is set and bit 15 is cleared, the tran sducer counts are divided by four before being used by the MMC120. When bits 14 and 15 are both set, the transducer counts are divided by eight.

Bit 15 - Divide by 2

When this bit is set and bit 14 is cleared, the tran sducer counts are divided by two before being used by th e MMC120. When bits 14 and 15 are both set, the transducer counts are divided by eight.

Bit 16 - Integrator Limit

When this bit is cleared, the integrator limit is 20%. When the bit is set, the limit is 80%. If the integrator tries to go above the limit, the Integrator Windup bit in the Status word is set and the integrator value is held at the limit. The integrator limit is designed to prevent the drive output from saturating.

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MMC120 Linear Motion Control Module Motion Control Parameters

CONFIGURATION Word Bit Map

The axis CONFIGURATION word contains 16 bits of in formation. This hexadecimal table provides an easy wayto convert hexadecimal numbers to bit patterns.

F 1111 1111 1111 1111

E 1110 1110 1110 1110 Hexadecimal To D 1101 1101 1101 1101 Binary Conversion C 1100 1100 1100 1100 Table B 1011 1011 1011 1011

A 1010 1010 1010 1010

9 1001 1001 1001 1001

8 1000 1000 1000 1000

7 0111 0111 0111 0111

6 0110 0110 0110 0110

5 0101 0101 0101 0101

4 0100 0100 0100 0100

3 0011 0011 0011 0011

2 0010 0010 0010 0010

1 0001 0001 0001 0001

0 0000 0000 0000 0000

_______ _______ _______ _______ |||||||||||||||||||| ||||||||||||1|1|1| |1|1|1|1| |1|2|3|4| |5|6|7|8| |9|0|1|2| |3|4|5|6|

Bit Definition |_|_|_|_| |_|_|_|_| |_|_|_|_| |_|_|_|_|

---------------- //// //// //// //// Transducer Type/8 Recirc - 01 -//// //// //// //// Transducer Type/4 Recirc - 02 --/ / / //// //// //// Transducer Type/2 Recirc - 03 ---/ / //// //// //// Transducer Type/1 Recirc - 04 ----/ //// //// ////

//// //// //// Reserved ----------------- 05 ------//// //// //// Reserved ----------------- 06 -------/ / / //// //// Reserved ----------------- 07 --------/ / //// //// Reserved ----------------- 08 ---------/ //// ////

//// //// Reserved ----------------- 09 -----------//// //// Reverse Drive Mode ------- 10 ------------/ / / //// Absolute Mode ------------ 11 -------------/ / //// Continue Mode ------------ 12 --------------/ ////

//// Simulate Mode ------------ 13 ----------------//// Divide by 4 -------------- 14 -----------------/ / / Divide by 2 -------------- 15 ------------------/ / Integrator Limit --------- 16 -------------------/

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Motion Control Parameters MMC120 Linear Motion Control Module

SCALE (Default: 30300) Range: -32767 to 32767, excluding 0

See the Startup section (page 20) for additional information.

TIP: Use DCS120 commands P0 and P1 to help calculate SCALE an d OFFSET.

The SCALE par ameter is used to calculate the ACTUAL POSITION in Position Units from the TRANSDUCER COUNTS. Position Units can be0.001", 0.1 mm, etc. The primary use for the SCALE parameter is to compensatefor variations in magnetostrictive transducers. It can also be used to convert to non-standard units for special applications.

SCALE is defined as 32768 times the number of Position Units per TRANSDUCER COUNT:

(P0 - P1)

SCALE =  x 32768

(C0 - C1)

Where P0 and P1 are two positions and C0 and C1 are the corresponding transducer counts. Magnetostrictive displacement transducers have a calibration number (nominally 9.012 microseconds per

inch) an d the MMC120 has a 60 MHz oscillator with both edges counted, for an effective counter speed of 120 MHz. To determine the SCALE for a magnetostrictive transducer use the following formula:

Position Units per Inch x 32768

SCALE =  xSign

Cal. Number (µs/in) x 120 (MHz)

Where Sign equals +1 when an extend move yield increasing ACTUAL POSITION counts, and it equals -1 when an extend move yields decreasing ACTUAL POSITION counts. Negative SCALE values indicate the axis moves in reverse. That is, the ACTUAL POSITION decrease as the TRANSDUCER COUNTS increase.

The calibration number must be specified in the same un its as th e Position Units (inches, mm, etc.). Position Units are generally 0.001 inches or 0.1 mm. Usuallythere are 1000 Position Units per i nch when the calibration number is in microseconds per in ch.

The ACTUAL POSITION is determined as follow s:

TRANSDUCER COUNTSxSCALE

ACTUAL POSITION =  + OFFSET

32768

NOTE: When the SCALE parameter is changed, the EXTEND LIMIT, RETRACT LIMIT, and OFFSET must also

be changed.

SCALE Calculation Examples

Example 1

For a system using a magnetostrictive transducer with a calibration number of 9.0110 µs per inch and a position un it of 0.001 inch, the SCALE will be:

1000(Position Units Per Inch) X 32768

SCALE =  = 30304

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