Datasheet MC1401A, MC1401A-P, MC1101A, MC1101A-P, MC1201A Datasheet (PMD)

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Available in 1, 2, or 4 axes configurations

32-bit position, velocity, acceleration and jerk

Choice of S-curve, trapezoidal, or contoured

Electronic gearing

1.0 megacount/sec quadrature incremental encoder

Choice of PWM or DAC motor output signals

with pre-load

Programmable host interrupts

Host

Processor

MC1401A

(I/O & CP)

Axis 1

Axis 2

Axis 3

Axis 4

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Features

Provides trajectory generation and servo loop closure

registers Two directional travel-limit switches per axis

velocity profile modes Programmable loop rate to 100 micro sec

Choice of either PID or PI with velocity feedforward servo control loops

with index position capture Parallel encoder and resolver input support

High speed home-signal position capture "On the fly" control of profile and filter parameters

Programmable torque limit Easy to use packet-oriented host protocol

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General Descripti on

The MC1401A is a 2-IC general purpose motion contr ol chipset available in one, two, or four axis configurations. It provides trajectory generation and clo sed-loop digital servo control for a large variety of servo motors. It uses incremental or absolute encoder positi on feedback signals, and a DAC or P WM compatible ou tput drive. Axe s can be progra m m ed either independently or in synchrony to allow advanced multi-axis motion such as ci rcular and contin uous-path profiles.

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Typical Configuration

Amp

The MC1401A is functionally similar to other members of PMD's 1st generation chipset family, provid i ng software an d architectural compatibility with these chipsets. All of these products support advanced features such as S-curve profile generation, bi-directional motion-travel limit switches, and separate hom e and index positio n capture signals.

The chipset is controlled by a host processor which interfaces with the chipset vi a an 8-bit, bi-directional port. Communications

(MC1401A,

MC1201A only)

(MC1401A only)

to/from the chi pset consist of pack et-oriented messages. A ho st interrupt line is provided so that the chipset can signal the host when special condi tions occur such as enc o der index pulse received.

Each axis interfaces to either a quadrature encoder with an optional index pulse, or a parallel-word device such as an absolute enco der or resolver . For motor a m pl if i er output, PWM signals are provided, as well as DAC-compatible signals with up to 16 bits of resolution.

The chipset is packaged in 2 68-pin PLCC pa ck ages. Both chips utilize CMOS technology and are powered by 5 volts.

Doc. Rev. 6.14, Nov , 1997

Performance Motion Dev ices, In c. 12 Waltham St. Le xington, M A 02421 te l: 781. 674.98 60 fax: 781.674.9 861 www.pmdcorp.com

Product Family Overview.......................................Page 3

Introduction ............................................................ Page 3

Family Summary..................................................... Page 3

Electrical Characteristics....................................... Page 4

Absolute Maximum Ratings..................................Page 4

Operating Ratings................................................. Page 4

DC Electrical Characteristics................................ Page 5

AC Electrical Characteristics................................Page 5

I/O Timing Diagrams............................................. Page 7

Pinouts....................................................................Page 13

MC1401A. MC1201A............................................ Page 13

MC1101A, MC1401A-P........................................ Page 14

MC1201A-P, MC1101A-P.....................................Page 15

Pin Descriptions.................................................... Page 16

Theory of Operations............................................. Page 20

Trajectory Profile Generation................................ Page 21

S-curve Point to Point....................................... Page 22

Trapezoidal Point to Point.................................Page 23

Velocity Contouring...........................................Page 23

Electronic Gear.................................................Page 24

Trajectory Control................................................. Page 24

Halting The Trajectory......................................Page 24

Motion Complete Status...................................Page 25

Digital Servo Filtering ........................................... Page 25

Motor Limit........................................................Page 26

Motor Bias........................................................ Page 26

Parameter Loading & Updating............................Page 26

Manual Update.................................................Page 27

Breakpoints....................................................... Page 27

External Breakpoints and Homing.................... Page 28

Disabling Automatic Profile Update..................Page 28

Travel Limit Switches............................................ Page 28

Motion Error Detection and Recovery.................. Page 29

Recovering From a Motion Error......................Page 29

Axis Timing........................................................... Page 29

Host Communications .......................................... Page 30

Electrical Interface............................................ Page 30

Packet Format..................................................Page 30

Packet Checksum.............................................Page 31

Illegal Commands .............................................Page 31

Command Errors...............................................Page 31

Axis Addressing....................................................Page 31

Axis Status............................................................Page 32

Status Word ......................................................Page 32

Miscellaneous Mode Status Word.....................Page 32

Host Interrupts.......................................................Page 32

Encoder Position Feedback..................................Page 34

Incremental Encoder Input................................Page 34

Encoder Filtering...............................................Page 34

High Speed Position Capture............................Page 34

Parallel-Word Device Input................................ Page 34

Parallel-Word Device Interfacing.......................Page 35

Motor Outputs.......................................................Page 35

Motor Output Control.........................................Page 35

PWM Output......................................................Page 36

12-Bit DAC Output.............................................Page 36

16-Bit DAC Output.............................................Page 36

Host Commands .....................................................Page 38

Command Summary.............................................Page 38

Command Reference............................................Page 40

Axis Control.......................................................Page 40

Profile Generation.............................................Page 41

Digital Filter.......................................................Page 45

Parameter Update............................................. Page 47

Interrupt Processing..........................................Page 50

Status/Mode......................................................Page 51

Encoder.............................................................Page 52

Motor.................................................................Page 52

Miscellaneous ...................................................Page 54

Application Notes ...................................................Page 58

Interfacing to ISA bus............................................Page 58

Parallel-Word Device Interface .............................Page 60

PWM Motor Interface............................................Page 62

16-Bit Parallel DAC Motor interface......................Page 64

16-Bit Serial DAC Motor Interface.........................Page 66

Performance Motion Devices, Inc. does not assume any responsibility for use of any circuitry described in this manual, nor does it make any guarantee as to the accuracy of this manual. Performance Motion Devices, Inc. reserves the right to change the circuitry described in this manual, or the manual itself, at any time.

The components described in this manual are not authorized for use in life-support systems without the express written permission of Performance Motion Devices, Inc.

Product Family Overview

MC1401 series MC1231 series MC1241 series MC1451 series

# of axes 4, 2, or 1 2 or 1 2 or 1 4, 2, or 1

Motors Supported DC Servo Brushless Servo Stepper Stepper

Encoder Format Incremental (no dash version)

and Parallel ('-P' version)

Output Format DC servo Sinusoidally

S-curve profiling Yes Yes Yes Yes

Electronic gearing Yes Yes Yes Yes

On-the-fly changes Yes Yes Yes Yes

Limit switches Yes Yes Yes Yes

PID & feedforward Yes Yes - -

PWM output Yes Yes Yes -

DAC-compatible output Yes Yes Yes -

Pulse & direction output ---Yes

Index & Home signal Yes Yes Yes Yes (-E version)

Chipset p/n's MC1401A, MC1401A-P (4 axes)

MC1201A, MC1201A-P (2 axes) MC1101A, MC1101A-P (1 axis)

Developer's Kit p/n's: DK1401A, DK1401A-P DK1231A DK1241A DK1451A

Incremental Incremental Incremental (-E version)

Microstepping Pulse and Direction

commutated

MC1231A (2 axes) MC1131A (1 axis)

MC1241A (2 axes) MC1141A (1 axis)

MC1451A, MC1451A-E (4 axes) MC1251A, MC1251A-E (2 axes) MC1151A, MC1151A-E (1 axis)

Introduction

This manual describes the operational characteristics of the MC1401A, MC1201A, MC1101A, MC1401A-P, MC1201A-P, and MC1101A-P Motion Processors. These devices are members of PMD's 1st generation motion processor family, which consists of 16 separate products organized into four groups.

Each of these devices are complete chip-based motion controllers. They provide trajectory generation and related motion control functions. Depending on the type of motor controlled they provide servo loop closure, on-board commutation for brushless motors, and high speed pulse and direction outputs. Together these products provide a software-compatible family of dedicated motion processor chips which can handle a large variety of system configurations.

Each of these chips utilize a similar architecture, consisting of a highspeed DSP (Digital Signal Processor) computation unit , along with an ASIC (Application Specific Integrated Circuit). The computation unit contains special on-board hardware such as a multiply instruction that makes it well suited for the task of motion control.

Along with a similar hardware architecture these chips also share most software commands, so that software written for one chipset may be reused with another, even though the type of motor may be different.

This manual describes the operation of the MC1401A, MC1201A, MC1101A, MC1401A-P, MC1201A-P, and MC1101A-P chipsets. For technical details on other members of PMD's first ge neration motion processors see the corresponding product manual.

Family Summary

MC1401 series (MC1401A, MC1201A, MC1101A, MC1401A-P, MC1201A-P, MC1101A-P)

encoder signals (standard version) or parallel word encoder signals (-P version) and output a motor command in either PWM or DACcompatible format. These chipsets come in 1, 2 or 4 axis versions and can be used with DC brushed motors, or brushless motors using external commutation.

MC1231 series (MC1231A, MC1131A) -

incremental quadrature encoder signals and output sinusoidally commutated motor signals appropriate for driving brushless motors. They are available in one or two axis versions. Depending on the motor type they output two or three phased signals per axis in either PWM or DAC-compatible format.

MC1241 series (MC1241A, MC1141A)

internal microstepping generation for stepping motors. They are available in a one or a two-axis version. Two phased signals are output per axis in either PWM or DAC-compatible format. An incremental encoder signal can be input to confirm motor position.

MC1451 series (MC1451A, MC1251A, MC1151A, MC1451A-E, MC1251A-E, MC1151A-E) -

pulse and direction signal output appropriate for driving step motorbased systems. They are available in a one, two, or four-axis version and are also available with quadrature encoder input.

Each of these chipsets has an associated Chipset Developer's Kit available for it. For more information contact your PMD representative.

- These chipsets take in incremental

These chipsets take in

- These chipsets provide

These chipsets provide very high speed

Electrical Characteristics

Overview

Interconnections between the two chips consist of a data bus and various control and synchronization signals. The following table summarizes the signals that must be interconnected for the chipset to function properly. For each listed signal the I/O chip pin on the left side of the table is directly connected to the pin to the right.

The MC1401A-consists of two 68 pin PLCC's both fabricated in CMOS. The Peripheral Input/Output IC (I/O chip) is responsible for interfacing to the host processor and to the position input encoders. The Command Processor IC (CP chip) is responsible for all host command, profile and servo computations, as well as for outputting the PWM and DAC signals.

The following figure shows a typical system block diagram, along with the pin connections between the I/O chip and the CP chip.

Motor

(4 axis)

Encoder

(1-4 axis)

I/O

Host

Processor

Data4-11

I/OAddr0-3

I/OWrite

I/OCntrl0-3

ClkOut

Amplifier

(1-4 axis)

I/O Chip Signal Name

I/O Chip Pin

CP Chip Signal Name

CP Chip Pin

CPData4 18 Data4 50 CPData5 5 Data5 49 CPData6 6 Data6 46 CPData7 7 Data7 43 CPData8 8 Data8 40 CPData9 17 Data8 39 CPData10 3 Data10 36 CPData11 1 Data11 35 CPAddr0 68 I/OAddr0 28 CPAddr1 27 I/OAddr1 9 CPAddr2 29 I/OAddr2 6 CPAddr3 12 I/OAddr3 5 CPCntr0 20 I/OCntr0 16 CPCntr1 36 I/OCntr1 18 CPCntr2 22 I/OCntr2 68 CPCntr3 63 I/OCntr3 67 CPWrite 2 I/OWrite 15 CPClk 46 ClkOut 19

For a complete description of all pins see the 'Pin Descriptions' section of this manual.

Unless specifically noted otherwise, the term 'MC1401A' refers to the MC1401A, MC1201A, MC1101A, MC1401A-P, MC1201A-P, and MC1101A-P Motion Processors.

The CP and I/O chips function together as one integrated motion processor. The major components connected to the chip set are the Encoder (4, 2, or 1 axes), the motor amplifier (4, 2, or 1 axes), and the host processor.

For the standard MC1401A parts (non '-P' parts), the encoder signals are input to the I/O chip in quadrature format. For the '-P' parts the encoder information is input directly into the CP chip, via an 8 bit data bus and various control signals.

The chipset's motor output signals are connected to the motor amplifier. Two types of output are provided; PWM (pulse width modulation), and DAC-compatible signals used with an external DAC (digital to analog converter).

The host processor is interfaced via an 8-bit bi-directional bus and various control signals. Host communication is coordinated by a ready/busy signal, which indicates when communication is allowed.

Absolute Maximum Ratings

Unless otherwise stated, all electrical specifications are for both the I/O and CP chips.

Storage Temperature, Ts.....................-55 deg. C to +150 deg. C

Supply Voltage, Vcc.............................-0.3 V to +7.0 V

Power Dissipation, Pd..........................650 mW (I/O and CP

combined)

Operating Ratings

Operating Temperature, Ta .................0 deg. C to +70 deg. C*

Nominal Clock Frequency, Fclk...........25.0 Mhz

Supply Voltage, Vcc.............................4.75 V to 5.25 V

* Industrial and Military operating ranges also available. Contact your PMD representative for more information.

DC Electrical Characteristics

(Vcc and Ta per operating ratings, Fclk = 25.0 Mhz)

Symbol Parameter Min. Max. Units Conditions

Vcc Supply Voltage 4.75 5.25 V

Idd Supply Current 100 mA open outputs

Input Voltages

Vih Logic 1 input voltage 2.0 Vcc + 0.3 V

Vil Logic 0 input voltage -0.3 0.8 V

Vihclk Logic 1 voltage for clock pin

(ClkIn)

Vihreset Logic 1 voltage for reset pin

(reset)

Output Voltages

Voh Logic 1 Output Voltage 2.4 V @CP Io = 300 uA

Vol Logic 0 Output Voltage 0.33 V @CP Io = 2 mA

Iout Tri-State output leakage current -20 20 uA 0 < Vout < Vcc

Iin Input current -50 50 uA 0 < Vi < Vcc

Iinclk Input current ClkIn -20 20 uA 0 < Vi < Vcc

3.0 Vcc+0.3 V

4.0 Vcc+0.3 V

AC Electrical Characteristics

(see reference timing diagrams) (Vcc and Ta per operating ratings; Fclk = 25.0 Mhz) (~ character indicates active low signal)

@I/O Io = 4 mA

Timing Interval T# Min. Max. Units Encoder and Index Pulse Timing

Motor-Phase Pulse Width T1 1.6 uS Dwell Time Per State T2 0.8 uS Index Pulse Setup and Hold (relative to Quad A and Quad B low)

Reset Timing

Stable Power to Reset 0.25 Sec Reset Low Pulse Width 1.0 uS

Clock Timing

Clock Frequency (Fclk) 6.7 25.6 Mhz Clock Pulse Width T4 19.5 75 (note 2) nS Clock Period T5 39 149 (note 2) nS

T3 0 uS

Timing Interval T# Min. Max. Units Command Byte Write Timing

~HostSlct Hold Time T6 15 2000 (note 3) nS ~HostSlct Setup Time T7 10 nS HostCmd Setup Time T8 10 nS Host Cmd Hold Time T9 25 nS HostRdy Delay Time T13 70 nS ~HostWrite Pulse Width T14 50 nS Write Data Setup Time T15 35 nS Write Data Hold Time T16 30 nS

Data Word Read Timing

~HostSlct Hold Time T6 15 2000 (note 3) nS ~HostSlct Setup Time T7 (read only) - 20 nS HostCmd Setup Time T8 (read only) - 20 nS HostCmd Hold Time T9 25 nS Read Data Access Time T10 50 nS Read Data Hold Time T11 10 nS ~HostRead high to HI-Z Time T12 50 nS HostRdy Delay Time T13 70 nS Read Recovery Time T17 60 nS

Data Word Write Timing

~HostSlct Hold Time T6 15 2000 (note 3) nS ~HostSlct Setup Time T7 10 nS HostCmd Setup Time T8 10 nS HostCmd Hold Time T9 25 nS HostRdy Delay Time T13 70 nS ~HostWrite Pulse Width T14 50 nS Write Data Setup Time T15 35 nS Write Data Hold Time T16 30 nS Write Recovery Time T18 60 nS

DAC Interface Timing

I/OAddr Stable to ~I/OWrite setup time T19 35 nS ~I/OWrite Pulse Width T20 56 95 nS Data Hold Time After ~I/OWrite T21 17 nS ClkOut Low to I/OAddr stable T22 10 40 nS ClkOut Low to ~I/OWrite Low T23 75 92 nS ClkOut Low to Data Valid T24 92 nS ClkOut Cycle Time T25 160 typical (note 4) nS I/OAddr Stable to DACSlct High T26 66 nS ~I/OWrite Low to DACSlct High T27 44.5 nS

PWM Output Timing

PWM Output Frequency 24.5 Khz

Parallel-Word Enc oder Timing (-P versi ons only)

ClkOut Period T28 160 typical (note 4) nS I/OCtrnl0 Delay Time T29 35 47 nS Data Setup Time to ClkOut T30 40 nS I/OAddr Stable to DACSlct High T31 22.0 27.0 uSec Convert Pulse Width T32 320 nSec

note 1 ~HostSlct and HostCmd may optionally be de-asserted if setup and hold times are met. note 2 Chip-set performance figures and timing information valid at Fclk = 25.0 only. For timing information & performance parameters at Fclk <

25.0 Mhz, call PMD.

note 3 Two micro seconds maximum to release interface before chip set responds to command note 4 ClkOut from CP is 1/4 frequency of ClkIn (CP chip).

I/O Timing Diagrams

The following diagrams show the MC1401A electrical interface timing. T#' values are listed in the above timing chart.

Quadrature Encoder Input Timing

Quad A

Quad B

~Index

ClkIn

T2 T2

Clock Timing

T4 T4 T5

Index = ~A * ~B * ~IND

Command Byte Write TIming

~HostSlct

HostCmd

~HostWrite

HostData0-7

HostRdy

T14

T15

T16

T13

Data Word Read TImi ng

~HostSlct

HostCmd

~HostRead

HostData0-7

HostRdy

Note 1

T17

T12

High-Z High-Z High-Z

High Byte

T10

T11

Low

Byte

T13

Data Word Write TIming

~HostSlct

HostCmd

~HostWrite

HostData0-7

HostRdy

T14

T15

High Byte

T16

T18

Note 1

T14

T15

Low

Byte

T16

T13

ClkOut

I/OAddr

~I/OWrite

DAC Interface Timing

T25

T22

T19

T23

T20

Data 0-11,

DACAddr0,1

DACSlct

T24

T21

T27

T26

ClkOut

Parallel Word Device Read Timing

T28

I/OCntrl0

Data0-11, DACLow0-3

PosSlct

Dac16Addr0, 1

Convert

12345

T29

T30

T31

T32

One data read shown. Axis address read sequence is 1, 2, 4, 3

Legend

1 - Instruct i on Fetch 2 - Instruct i on Fetch 3 - Read the data value 4 - Instruct i on Fetch 5 - Instruct i on Fetch

6 - Convert strobe

Pinouts

(Top view)

27 43

4, 21, 25, 38, 55

QuadA1

QuadB1

Index1

Home1

QuadA2

QuadB2

Index2

Home2

QuadA3

QuadB3

Index3

Home3

QuadA4

QuadB4

Index4

Home4

DACSlct

CPClk

I/OClkIn

I/OClkOut

CPAddr2

CPAddr3

CPWrite

CPCntrl0

CPCntrl1

I/O

VCC

I/O

GND

CPCntrl2 CPCntrl3

HostCmd

HostRdy HostRead HostWrite

HostSlct HostIntrpt

HostData0 HostData1 HostData2 HostData3 HostData4 HostData5 HostData6 HostData7

CPData4 CPData5 CPData6 CPData7 CPData8

CPData9 CPData10 CPData11

CPAddr0

CPAddr1

MC1401A Pinouts

22 63 41 37 51 47 48 44 50 61 53 65 67 62 64 60 18

5 6 7 8

1 68 27

(Top view)

27 43

4, 22, 33

56 55 54 53

30 29 24 19 17 16 18 68 67 64 63 62 61

8 7 2 1

PWMMag1 PWMSign1 PWMMag2 PWMSign2 PWMMag3 PWMSign3 PWMMag4 PWMSign4 DAC16Addr0 DAC16Addr1 ClkIn ClkOut Reset I/OCntrl0 I/OCntrl1 I/OCntrl2 I/OCntrl3 DACLow0 DACLow1 DACLow2 DACLow3

VCC

GND

Data0 Data1 Data2 Data3 Data4 Data5 Data6 Data7 Data8

Data9 Data10 Data11

I/OAddr0 I/OAddr1 I/OAddr2 I/OAddr3

I/OWrite PosLimit1 PosLimit2 PosLimit3 PosLimit4 NegLimit1 NegLimit2 NegLimit3 NegLimit4

60 59 58 57 50 49 46 43 40 39 36 35 28

9 6

5 15 52 45 42 38 51 44 41 37

14, 15, 32, 49, 54, 66

4, 21, 25, 38, 55

VCC

QuadA1

QuadB1

Index1

Home1

QuadA2

QuadB2

Index2

Home2

DACSlct

CPClk

I/OClkIn

I/OClkOut

CPAddr2

CPAddr3

CPWrite

CPCntrl0

CPCntrl1

CPCntrl2

CPCntrl3

CPAddr0

CPAddr1

I/O

GND

14, 15, 32, 49, 54, 66

HostCmd

HostRdy HostRead HostWrite

HostSlct HostIntrpt

HostData0 HostData1 HostData2 HostData3 HostData4 HostData5 HostData6 HostData7

CPData4 CPData5 CPData6 CPData7 CPData8

CPData9 CPData10 CPData11

MC1201A Pinouts

41 37 51 47 48 44 50 61 53 65 67 62 64 60 18

5 6 7 8

3 1

PWMMag1

PWMSign1

PWMMag2

PWMSign2

DAC16Addr0

DAC16Addr1

ClkIn

ClkOut

Reset

I/OCntrl0

I/OCntrl1

I/OCntrl2

I/OCntrl3

DACLow0

DACLow1

DACLow2

DACLow3

3, 34

4, 22, 33

VCC

GND

3, 34

Data0 Data1 Data2 Data3 Data4 Data5 Data6 Data7 Data8

Data9 Data10 Data11

I/OAddr0 I/OAddr1 I/OAddr2 I/OAddr3

I/OWrite PosLimit1 PosLimit2 NegLimit1 NegLimit2

60 59 58 57 50 49 46 43 40 39 36 35 28

9 6

5 15 52 45 51 44

4, 21, 25, 38, 55

MC1101A Pinouts

4, 22, 33

VCC

HostCmd

HostRdy

QuadA1

QuadB1

Index1

Home1

DACSlct

CPClk

I/OClkIn

I/OClkOut

CPAddr2

CPAddr3

CPWrite

CPCntrl0

CPCntrl1

CPCntrl2

CPCntrl3

CPAddr0

CPAddr1

I/O

GND

14, 15, 32, 49, 54, 66

HostRead HostWrite

HostSlct

HostIntrpt HostData0 HostData1 HostData2 HostData3 HostData4 HostData5 HostData6 HostData7

CPData4 CPData5 CPData6 CPData7 CPData8

CPData9 CPData10 CPData11

41 37 51 47 48 44 50 61 53 65 67 62 64 60 18

5 6 7 8

3 1

8 56 30 29 24 19 17 16 18 68 67 64 63 62 61

PWMMag1 PWMSign1 DAC16Addr0 DAC16Addr1 ClkIn ClkOut Reset I/OCntrl0 I/OCntrl1 I/OCntrl2 I/OCntrl3 DACLow0 DACLow1 DACLow2 DACLow3

VCC

GND

3, 34

Data0 Data1 Data2 Data3 Data4 Data5 Data6 Data7 Data8

Data9 Data10 Data11

I/OAddr0 I/OAddr1 I/OAddr2 I/OAddr3

I/OWrite PosLimit1 NegLimit1

60 59 58 57 50 49 46 43 40 39 36 35 28

9 6

5 15 52 51

MC1401A-P Pinouts

4, 21, 25, 38, 55

4, 22, 33

VCC

HostCmd

HostRdy HostRead HostWrite

DACSlct

CPClk

I/OClkIn

I/OClkOut

CPAddr2

CPAddr3

CPWrite

CPCntrl0

CPCntrl1

CPCntrl2

CPCntrl3

CPAddr0

CPAddr1

I/O

GND

14, 15, 32, 49, 54, 66

HostSlct HostIntrpt

HostData0 HostData1 HostData2 HostData3 HostData4 HostData5 HostData6 HostData7

CPData4 CPData5 CPData6 CPData7 CPData8

CPData9 CPData10 CPData11

41 37 51 47 48 44 50 61 53 65 67 62 64 60 18

5 6 7 8

3 1

56 55 54 53

30 29 31 32 24 19 17 16 18 68 67 64 63 62 61

7 2 1

PWMMag1 PWMSign1 PWMMag2 PWMSign2 PWMMag3 PWMSign3 PWMMag4 PWMSign4 DAC16Addr0 DAC16Addr1 PosSlct Convert ClkIn ClkOut Reset I/OCntrl0 I/OCntrl1 I/OCntrl2 I/OCntrl3 DACLow0 DACLow1 DACLow2 DACLow3

VCC

GND

3, 34

Data0 Data1 Data2 Data3 Data4 Data5 Data6 Data7 Data8

Data9 Data10 Data11

I/OAddr0 I/OAddr1 I/OAddr2 I/OAddr3

I/OWrite PosLimit1 PosLimit2 PosLimit3 PosLimit4 NegLimit1 NegLimit2 NegLimit3 NegLimit4

60 59 58 57 50 49 46 43 40 39 36 35 28

9 6

5 15 52 45 42 38 51 44 41 37

4, 21, 25, 38, 55

MC1201A-P Pinouts

4, 22, 33

VCC

HostCmd

HostRdy HostRead HostWrite

DACSlct

CPClk

I/OClkIn

I/OClkOut

CPAddr2

CPAddr3

CPWrite

CPCntrl0

CPCntrl1

CPCntrl2

CPCntrl3

CPAddr0

CPAddr1

I/O

GND

14, 15, 32, 49, 54, 66

HostSlct HostIntrpt

HostData0 HostData1 HostData2 HostData3 HostData4 HostData5 HostData6 HostData7

CPData4 CPData5 CPData6 CPData7 CPData8

CPData9 CPData10 CPData11

41 37 51 47 48 44 50 61 53 65 67 62 64 60 18

5 6 7 8

3 1

56 55

30 29 31 32 24 19 17 16 18 68 67 64 63 62 61

8 7

PWMMag1 PWMSign1 PWMMag2 PWMSign2 DAC16Addr0 DAC16Addr1 PosSlct Convert ClkIn ClkOut Reset I/OCntrl0 I/OCntrl1 I/OCntrl2 I/OCntrl3 DACLow0 DACLow1 DACLow2 DACLow3

VCC

GND

3, 3 4

Data0 Data1 Data2 Data3 Data4 Data5 Data6 Data7 Data8

Data9 Data10 Data11

I/OAddr0 I/OAddr1 I/OAddr2 I/OAddr3

I/OWri te PosLimit1 PosLimit2

NegLimit1 NegLimit2

60 59 58 57 50 49 46 43 40 39 36 35 28

9 6

5 15 52 45 51 44

MC1101A-P Pinouts

4, 21, 25, 38, 55

4, 22, 33

VCC

HostCmd

HostRdy HostRead HostWrite

DACSlct

CPClk

I/OClkIn

I/OClkOut

CPAddr2

CPAddr3

CPWrite

CPCntrl0

CPCntrl1

CPCntrl2

CPCntrl3

CPAddr0

CPAddr1

I/O

GND

14, 15, 32, 49, 54, 66

HostSlct

HostIntrpt HostData0 HostData1 HostData2 HostData3 HostData4 HostData5 HostData6 HostData7

CPData4 CPData5 CPData6 CPData7 CPData8

CPData9 CPData10 CPData11

41 37 51 47 48 44 50 61 53 65 67 62 64 60 18

5 6 7 8

3 1

8 56 30 29 31 32 24 19 17 16 18 68 67 64 63 62 61

PWMMag1 PWMSign1 DAC16Addr0 DAC16Addr1 PosSlct Convert ClkIn ClkOut Reset I/OCntrl0 I/OCntrl1 I/OCntrl2 I/OCntrl3 DACLow0 DACLow1 DACLow2 DACLow3

VCC

GND

3, 34

Data0 Data1 Data2 Data3 Data4 Data5 Data6 Data7 Data8

Data9 Data10 Data11

I/OAddr0 I/OAddr1 I/OAddr2 I/OAddr3

I/OWrite PosLimit1 NegLimit 1

60 59 58 57 50 49 46 43 40 39 36 35 28

9 6

5 15 52 51

Pin Descriptions

The following tables provide pin descriptions for the MC1401A and MC1401A-P series chipsets.

IC Pin Name Pin # Description/Functionality I/O Chip Pinouts

I/O QuadA1

QuadB1 QuadA2 QuadB2 QuadA3 QuadB3 QuadA4 QuadB4

I/O ~Index1

~Index2 ~Index3 ~Index4

28 42 26 30 40 35 39 34

24 9 19 16

Quadrature A, B channels for axis 1 - 4 (input). Each of these 4 pairs of quadrature (A, B) signals provide the position feedback for an incremental encoder. When the encoder is moving in the positive, or forward direction, the A signal leads the B signal by 90 degs. The quadrature signals must stay in the same state for .8 uSec to register a valid encoder state, resulting in a maximum theoretical encoder state capture rate of 1.2 Mcounts/sec. Actual maximum rate will vary depending on signal noise. Typical maximum is 1.0 Mcounts/sec.

NOTE: Many encoders require a pull-up resistor on each of these signals to establish a proper high signal (check the encoder electrical specifications)

NOTE: For MC1401A all 8 pins are valid. For MC1201A pins for axes 1 & 2 only are valid. For MC1101A pins for axis 1 only are valid. Invalid axis pins can be left unconnected.

NOTE: Not valid for -P parts. Index encoder signals for axis 1-4 (input). Each of these 4 signals indicate the index flag state from the encoder. A valid index pulse is recognized by the chip set when the index flag transitions low, followed by the corresponding A and B channels of the encoder transitioning low. The index pulse is recognized at the later of the A or B transitions. If not used this signal must be tied high.

NOTE: For MC1401A all 4 pins are valid. For MC1201A pins for axes 1 & 2 only are valid. For MC1101A pin for axis 1 only is valid. Invalid axis pins can be left unconnected.

NOTE: Not valid for -P parts.

I/O ~Home1

~Home2 ~Home3 ~Home4

I/O DACSlct 33 DAC Select (output). This signal is asserted high to select any of the available DAC output

I/O CPClk 46 I/O chip clock (input). This signal is connected directly to the ClkOut pin (CP chip) and

I/O I/OClkIn 52 Phase shifted clock (input). This signal is connected to I/OClkOut (I/O chip), and inputs a

I/O I/OClkOut 45 Phase shifted clock (output). This signal is connected to I/OClkIn (I/O chip), and outputs a

I/O CPAddr0

CPAddr1 CPAddr2 CPAddr3

13 23 11 10

68 27 29 12

Home signals for axis 1-4 (input). Each of these signals provide a general purpose input to the hardware position capture mechanism. A valid home signal is recognized by the chipset when the home flag transitions low. These signals have a similar function as the ~Index signals, but are not gated by the A and B encoder channels. For valid axis pins, If not used, this signal must be tied high. See below for valid pin definitions for the MC1401A, MC1201A, and MC1101A.

NOTE: For MC1401A all 4 pins are valid. For MC1201A pins for axes 1 & 2 only are valid. For MC1101A pin for axis 1 only is valid. Invalid axis pins can be left unconnected.

NOTE: Not valid for -P parts.

channels. For details on DAC decoding see description of DACAddr0-1 and DAC16Addr0-3 signals.

provides the clock signal for the I/O chip. The frequency of this signal is 1/4 the user-provided ClkIn (CP chip) frequency.

phase shifted clock signal.

phase shifted clock signal. I/O chip to CP chip communication address (input). These 4 signals are connected to the corresponding I/OAddr0-3 pins (CP chip), and together provide addressing signals to facilitate CP to I/O chip communication.

IC Pin Name Pin # Description/Functionality

I/O ~CPWrite 2 I/O chip to CP chip communication write (input). This signal is connected to the ~I/OWrite pin

(CP chip) and provides a write strobe to facilitate CP to I/O chip communication.

I/O CPCntrl0

CPCntrl1 CPCntrl2 CPCntrl3

I/O HostCmd 41 Host Port Command (input). This signal is asserted high to write a host command to the chip

I/O HostRdy 37 Host Port Ready/Busy (output). This signal is used to synchronize communication between

I/O ~HostRead 51 Host Port Read data (input). Used to indicate that a data word is being read from the chip set

I/O ~HostWrite 47 Host Port Write data (input). Used to indicate that a data word or command is being written to

I/O ~HostSlct 48 Host Port Select (input). Used to select the host port for reading or writing operations (low

I/O ~HostIntrpt 44 Host Interrupt (output). A low assertion on this pin indicates that a host interrupt condition

I/O HostData0

HostData1 HostData2 HostData3 HostData4 HostData5 HostData6 HostData7

I/O CPData4

CPData5 CPData6 CPData7 CPData8 CPData9 CPData10 CPData11

I/O Vcc 4, 21, 25, 38, 55 I/O chip supply voltage pin. All of these pins must be connected to the supply voltage. Supply

I/O GND 14, 15, 32, 49, 54,66I/O chip ground pin. All of these pins must be connected to the power supply return.

20 36 22 63

50 61 53 65 67 62 64 60 18 5 6 7 8 17 3 1

I/O chip to CP chip communication control (mixed). These 4 signals are connected to the corresponding I/OCntrl0-3 pins (CP chip), and provide control signals to facilitate CP to I/O chip communication.

set. It is asserted low to read or write a host data word to the chipset

the DSP and the host. HostRdy will go low (indicating host port busy) at the end of a host command write or after the second byte of a data write or read. HostRdy will go high (indicating host port ready) when the command or data word has been processed and the chip set is ready for more I/O operations. All host port communications must be made with HostRdy high (indicating ready).

Typical busy to ready cycle is 100.0 uSec.

(low asserts read).

the chip set (low asserts write).

assertion selects port). ~HostSlct must remain inactive (high) when the host port is not in use.

exists that may require special host action. Host Port Data 0-7 (bi-directional, tri-stated). These signals form the 8 bit host data port used during communication to/from the chip set. This port is controlled by ~HostSlct, ~HostWrite, ~HostRead and HostCmd.

I/O chip to CP chip data port (bi-directional). These 8 bits are connected to the corresponding Data4-11 pins on the CP chip, and facilitate communication to/from the I/O and CP chips..

voltage = 4.75 to 5.25 V

IC Pin Name Pin # Description/Functionality CP Chip Pinouts

CP PWMMag1

PWMMag2 PWMMag3 PWMMag4

CP PWMSign1

PWMSign2 PWMSign3 PWMSign4

CP PosLimit1

PosLimit2 PosLimit3 PosLimit4

CP NegLimit1

NegLimit2 NegLimit3 NegLimit4

CP DAC16Addr0

DAC16Addr13029

8 7 2 1 56 55 54 53 52 45 42 38

51 44 41 37

PWM motor output magnitude signals (output). When the chip set is in PWM output mode these pins provide the Pulse Width Modulated magnitude signal to the motor amplifier. Each PWM signal output directly corresponds to the axis # being driven.

PWM motor output sign signals for axis 1-4 (output). When the chip set is in PWM output mode these pins provide the Pulse Width Modulated sign signal to the motor amplifier for each axis.

Positive limit switch input for axis 1-4. These signals provide directional limit inputs for the positive-side travel limit of the axis. Upon powerup these signals default to "active high" interpretation, but the interpretation can be set explicitly using the SET_LMT_SENSE command. If not used these signals should be tied low for the default interpretation, or tied high if the interpretation is reversed.

NOTE: For MC1401A all 4 pins are valid. For MC1201A pins for axes 1 & 2 only are valid. For MC1101A pin for axis 1 only is valid. Invalid axis pins can be left un connected. Negative limit switch input for axis 1-4. These signals provide directional limit inputs for the negative-side travel limit of the axis. Upon powerup these signals default to "active high" interpretation, but the interpretation can be set explicitly using the SET_LMT_SENSE command. If not used these signals should be tied low for the default interpretation, or tied high if the interpretation is reversed.

NOTE: For MC1401A all 4 pins are valid. For MC1201A pins for axes 1 & 2 only are valid. For MC1101A pin for axis 1 only is valid. Invalid axis pins can be left un connected. Axis Address used during 16-bit DAC motor command output and parallel-word encoder input (output). When used to encode the motor DAC address or the parallel word encoder address these signals are encoded as follows: Dac16Addr1 Dac16Addr0 Addressed Encoder Low Low Axis 1 Low High Axis 2 High Low Axis 3 High High Axis 4

To read a parallel position word from an external device, the chipset loads DAC16Addr0-1 with the axis # and PosSlct is asserted low.

To write a valid DAC motor command value DACSlct (I/O chip) and I/OAddr0-3 (CP chip) must be high, and I/OWrite (CP chip) must be low. The 16 bit DAC data word is organized as follows: High twelve bits are in Data0-11 (CP chip), and low 4 bits are in DACLow0-3 (CP

chip). CP ClkIn 24 Clock In (input). This pin provides the chip set master clock (Fclk = 25.0 Mhz) CP ClkOut 19 Clock Out (output). This pin provides a clock output which is 1/4 the ClkIn frequency. This pin

is connected to CPClk (I/O chip). CP ~Reset 17 Master chip set reset (input). When brought low, this pin resets the chip set to its initial

condition. Reset should occur no less than 250 mSec after stable power has been provided

to the chip set. CP I/OCntrl0

I/OCntrl1 I/OCntrl2 I/OCntrl3

16 18 68 67

I/O chip to CP chip communication control (mixed). These signals provide various inter-chip

control signals and are connected to the corresponding CPCntrl0-3 pins on the I/O chip.

IC Pin Name Pin # Description/Functionality

CP Data0

Data1 Data2 Data3 Data4 Data5 Data6 Data7 Data8 Data9 Data10 Data11

CP DACLow0

DACLow1 DACLow2 DACLow3

CP I/OAddr0

I/OAddr1 I/OAddr2 I/OAddr3

CP PosSlct 31 Parallel-word position-input device select (output). This pin selects the parallel word device(s)

60 59 58 57 50 49 46 43 40 39 36 35 64 63 62 61 28 9 6 5

Multi-purpose Data0-11. (Bi-directional). These pins have 3 functions:

1) Pins Data4-11 (8 bits total) are connected to the corresponding CPData4-11 pins on the

I/O chip, and are used to communicate between the CP and I/O chips

2) Pins Data0-11 hold the high 12 bits of the DAC output value when the output mode is set

to 16-bit DAC.

3) Pins Data0-11 input the high 12 bits of the parallel-word position data (-P version chipsets

only).

DACLow0-3 (output). These pins hold the lowest 4 bits of the 16 bit DAC output word when

DAC16 motor output mode is selected. In addition they input the low 4 bits of the parallel

word (-P version chip set only).

Multi-purpose Address0-3 (output). These pins are connected to the corresponding CPAddr0-

3 pins on the I/O chip. They have 2 functions; They provide addressing signals to facilitate

communication between the I/O chip and CP chip, and they are used during DAC data

decoding.

for reading.

To read a parallel position word from an external device, the chipset loads DAC16Addr0-1

with the axis # and PosSlct is asserted low.

Note: Only valid for -P parts. CP Convert 32 Parallel-word conversion start signal (output). This pin provides a signal which momentarily

strobes low at the end of the parallel word read sequence.

This signal is useful for starting A/D converters or for synchronizing external latch hardware

associated with the parallel-word read circuitry

Note: Only valid for -P parts. CP I/OWrite 15 Multi-purpose write (output). This pin is connected to CPWrite on the I/O chip. It has 2

functions:

1) It provides a control signal to the I/O chip to facilitate communication between the I/O chip

and CP chip.

2) It is used during DAC data decoding.

CP Vcc 4, 22, 33 CP chip supply voltage pin. All of these pins must be connected to the supply voltage. Supply

voltage = 4.75 to 5,.25 V CP GND 3, 34 CP chip ground pin. All of these pins must be connected to the power supply return.

Theory of Operations

Incremental Encoder

Index B A

Home

1/a

I/O Chip

Internal Block Diagram

1/a 1/a

Parallel I nput

(-P chipset only)

8 data

2 Control

PWM sign,

mag

1/phase 2

Motor Output

DAC address

DAC data

DAC, PWM signal generator (1-4 channels)

CP Chip

Quadrature

decoder

counter (1-4)

Position capture

Host I/O controller

185

host interr uptDataControl

The above figure shows an internal block diagram for the MC1401A and MC1401A-P series motion processors.

Each servo axis inputs the actual location of the axis using either incremental encoder signals or signals from a parallel-word input device such as an absolute encoder or resolver. If incremental signals are used then the incoming A, and B quadrature data stream is digitally filtered, and then passed on to a high speed up/down counter. Using the parallel-word interface a direct binary-encoded position of up to 16 bits is read by the chipset. Regardless of the encoder input method this position information is then used to maintain a 32-bit actual axis position counter.

If incremental feedback is used, then the chipset also supports the ability to capture the instantaneous position of each axis using an external trigger signal. The captured value may then later be retrieved by the host processor.

Position

Host command

generation and digital servo loop closure. In this mode the motor output value is controlled by the servo filter. Open loop mode, which is used for direct motor-control operations only, does not use the output of the servo filter, and allows the motor output value to be controlled directly by the host processor.

When closed loop mode operations are used the actual axis position is combined with the target position generated by the trajectory profile generator to calculate a position error, which is passed through a PID filter. The resultant value is then output by the chipset to an external amplifier using either PWM or DAC signals.

The following table summarizes the operational parameters of the MC1401-series chipsets.

Digital Servo filtering (1-4)

System Registers (1-4)

1/a

PosLimit

NegLimit

Trajectory profile

generator (1-4)

1/a

The chipset can be operated in two modes. Closed loop mode, which is the normal operating mode of the chipset, performs trajectory

MC1401-series Chipset Operational Parameters

Available configurations: 4 axes with incremental quadrature encoder input (MC1401A)

2 axes with incremental quadrature input (MC1201A) 1 axis with incremental quadrature input (MC1101A) 4 axes with parallel word encoder input (MC1401A-P) 2 axes with parallel word encoder input (MC1201A-P) 1 axes with parallel word encoder input (MC1101A-P)

Operating modes: Closed loop (motor command is driven from output of servo filter)

Open loop (motor command is driven from user-programmed register) Position range: -1,073,741,824 to 1,073,741,823 counts Velocity range: -16,384 to 16,383 counts/sample with a resolution of 1/65,536 counts/sample Acceleration range:

Jerk range: Trajectory profile generator modes: S-curve (host commands final position, max velocity, max acceleration, and jerk)

Electronic gear ratio range: 32768:1 to 1:32768 (negative and positive direction) Filter modes: PID+Vff (standard PID loop plus velocity feedforward plus bias offset) Filter parameter resolution: 16 bits Motor output modes: PWM (10 bits resolution @ 24.5 Khz)

Max incremental. encoder rate: Incremental: 1.0 Mcounts/sec Parallel-word: 80.0 Mcounts/sec Parallel encoder word size: 16 bits (read in 2 byte reads) (-P version parts only) Parallel encoder read rate: 10 kHz (reads all axes every 100 uSec) Servo loop rate range: standard, -P parts: 100* uSec minimum, 3,276 mSec max. Max servo loop rate: standard, -P parts: 100* uSec per enabled axis. # of limit switches per axis 2 (one for each direction of travel) # of position capture triggers: 2 (index, home signal) Capture trigger latency: 160 nSec # of host commands: 94

S-curve profile: - 1/2 to + 1/2 counts/sample2 with a resolution of 1/65,536 counts/sample

All others: -16,384 to 16,383 counts/sample2 with a resolution of 1/65,536 counts/sample

-1/2 to +1/2 counts/sample3, with a resolution of 1/4,294,967,296 counts/sample

Trapezoidal (host commands final position, max velocity and acceleration)

Velocity contouring (host commands max. velocity, acceleration)

Electronic Gear (Encoder position of one axis is used as position command for another axis). A total of 2

electronic gears are supported (2 encoders and 1 output each). Not available in MC1101A

DAC 16 bits

2. 2

* Exact servo loop time is 101.12 uSec, 100 uSec is an approximation

Trajectory Profile Generation

The trajectory profile generator performs calculations to determine the target position, velocity and acceleration at each servo loop. These calculations are performed taking into account the current profile mode, as well as the current profile parameters set by the host. Four trajectory profile modes are supported:

- S-curve point to point

- Trapezoidal point to point

- Velocity contouring

- Electronic Gear

The commands to select these profile modes are

SET_PRFL_S_CRV (to select the s-curve mode), SET_PRFL_TRAP (to select the trapezoidal mode) SET_PRFL_VEL (to select the velocity contouring mode) and SET_PRFL_GEAR (to select the electronic gear mode).

Throughout this manual various command mnemonics will be shown to clarify chipset usage or provide specific examples. See the Host Communications section for a description of host command nomenclature.

The profile mode may be programmed independently for each axis. For example axis #1 may be in trapezoidal point to point mode while axis #2 is in S-curve point to point.

Use the following figure showing a typical S-curve velocity vs. time graph for reference in reading the next section:

Generally, the axis should be at rest when switching profile modes. Under certain conditions however, switching into certain profile modes "on-the-fly" is allowed. See specific profile descriptions for details.

S-curve Point to Point

The following table summarizes the host specified profile parameters for the S-curve point to point profile mode:

Profile Parameter

Destination Position Maximum Velocity

Max. Accel.

Jerk

* uses 1/216 scaling. Chipset expects a 32 bit number which has been scaled by a factor of 65,536 from units of counts/sample time. For example to specify a velocity of 2.75 counts/sample time, 2.75 is multiplied by 65,536 and the result is sent to the chipset as a 32 bit integer (180,224 dec. or 2c000 hex.).

** uses 1/216 scaling. Chipset expects a 16 bit number which has been scaled by a factor of 65,536 from units of

counts/sample time2. For example to specify an acceleration of .175 counts/sample time2, .175 is multiplied by 65,536 and

the result is sent to the chipset as a 16 bit integer (11,469 dec. or 2ccd hex).

Representation & Range Units

signed 32 bits

counts

-1,073,741,824 to 1,073,741,823 unsigned 32 bits* (1/2

scaling)

counts/smpl 0 to 1,073,741,823 unsigned 16 bits ** (1/2

scaling)

counts/smpl 0 to 32,767

unsigned 32 bits *** (1/2

scaling)

counts/smpl 0 to 2,147,483,647

PhaseI.Phase

Phase

II.

III.

Phase

IV.

PhaseV.Phase

VI.

Phase

VII.

S-curve profile

The S-curve profile drives the axis at the specified jerk until the maximum acceleration is reached. (phase I). it will then drive the axis at jerk = 0 (constant acceleration) through phase II. It will then drive the

axis at the negative of the specified jerk though phase III, such that the axis reaches the specified maximum velocity with acceleration = 0. This

completes the acceleration phase. At the end of the acceleration phase of the move, the velocity will be constant, and the acceleration will be 0. At the appropriate time, the profile will then decelerate (phases V, VI and VII) symmetrically to the acceleration phase such that it arrives at the destination position with acceleration and velocity = 0.

There are several conditions where the actual velocity graph of an Scurve motion will not contain all of the segments shown in the above figure. For example, if the max. acceleration is not reached before the "half-way" point to the max. velocity, then the actual velocity profile will not contain a phase II or a phase VI segment (they will have a duration of 0 servo loops). Such a profile is shown below:

PhaseI.Phase

III.

Phase

IV.

PhaseV.Phase

VII.

*** uses 1/2 has been scaled by a factor of 4,294,967,296 (2

scaling. Chipset expects a 32 bit number which

32)

from units of counts/sample time3. For example to specify a jerk value of .0075 counts/sample time3, .0075 is multiplied by

4,294,967,296 and the result is sent to the chipset as a 32 bit integer (32,212,256 dec. or 1eb8520 hex).

S-curve that doesn't reach max. acceleration

Another such condition is if the position is specified such that max. velocity is not reached. In this case there will be no phase IV, and there may also be no phase II and VI, depending on where the profile is "truncated".

While the S-curve profile is in motion, the user is not allowed to change any of the profile parameters. The axis must be at rest before a new set of profile parameters can be executed. If parameters are changed during motion then a 'command error'

will occur, and all new parameters will be ignored except the position. See the section of this manual entitled "Command Error" for more information..

Vel.

Before switching to the S-curve point to point profile mode, the axis should be at a complete rest.

When the axis is in the S-curve profile mode, the SET_MAX_ACC command should be used to load the max. acceleration value. The alternate acceleration loading command SET_ACC can not be used.

Trapezoidal Point to Point

The following table summarizes the host specified profile parameters for the trapezoidal point to point profile mode:

Profile Parameter

Destination Position Maximum Velocity

Accel.

In the trapezoidal point to point profile mode the host specifies a destination position, a maximum velocity, and an acceleration. The trajectory is executed by accelerating at the commanded acceleration to the maximum velocity where it coasts until decelerating such that the destination position is reached with the axis at rest (zero velocity). If it is not possible to reach the maximum velocity (because deceleration must begin) then the velocity profile will have no "coasting" phase. The acceleration rate is the same as the deceleration rate.

A new maximum velocity and destination position can be specified while the axis is in motion. When this occurs the axis will accelerate or decelerate toward the new destination position while attempting to satisfy the new maximum velocity condition.

When in Trapezoidal point to point profile mode, to change the acceleration, the axis must come to a complete stop. After this has occurred, a new acceleration value can be loaded. If the acceleration parameter is changed during motion then a 'command error' will occur, and all updated parameters will be ignored except the position. See the section of this manual entitled "Command Errors" for more information.

Before switching to the Trapezoidal point to point profile mode, the axis should be at a complete rest.

The following figure shows a velocity profile for a typical point to point trapezoidal move, along with a more complicated move involving on the fly changes to the maximum velocity and the destination position.

Representation & Range Units

signed 32 bits

counts

-1,073,741,824 to 1,073,741,823 unsigned 32 bits (1/2

scaling)

counts/smpl 0 to 1,073,741,823 unsigned 32 bits (1/2

scaling)

counts/smpl 0 to1,073,741,823

Simple trapezoidal mode motion

Vel.

change max

velocity

change target

position

Complex trapezoidal mode motion

Velocity Contouring

The following table summarizes the host specified profile parameters for the Velocity contouring profile mode:

Profile Parameter

Maximum Velocity

Acceleration

* negative numbers using 1/216 scaling are handled no differently than positive numbers. For example if an

acceration value of -1.95 counts/sample time2 is desired, -

1.95 is multipled by 65,536 and the result is sent to the chipset (-127,795 dec. or fffe0ccd hex).

In this profile mode the host specifies two parameters, the commanded acceleration, and the maximum velocity. The trajectory is executed by continuously accelerating the axis at the commanded rate until the max. velocity is reached, or until a new acceleration command is given.

The maximum velocity value must always be positive. Motion direction is controlled using the acceleration value. Positive acceleration values result in positive motion, and negative acceleration values result in negative motion.

There are no restrictions on changing the profile parameters on the fly. Note that the motion is not bounded by position however. It is the responsibility of the host to generate acceleration and max. velocity command values which result in safe motion, within acceptable position limits.

The following figure shows a typical velocity profile using this mode.

Representation & Range Units

unsigned 32 bits (1/2

scaling)

counts/smpl 0 to 1,073,741,823 signed 32 bits* (1/2

scaling)

counts/smpl

-1,073,741,824 to 1,073,741,823

Time

Vel.

Example Velocity Contouring Mode

change

acceler a tion

change

max velocity

Time

In addition, the master /slave axis combinations are fixed. The following chart shows the allowed master/slave combinations for each chipset:

chipset p/n gear pairs (master -> slave) MC1401A #3 -> #1, #4 -> #2 MC1201A #2 -> #1 MC1101A not available

change max

velocity and acceler a tion

There are no restrictions on switching the profile mode to velocity contouring while the axis is in motion.

Electronic Gear

The following table summarizes the host specified profile parameters for the electronic gear profile mode:

Profile Parameter

Gear Ratio

* for example to specify a gear ratio of +1.5 to 1 the value

1.5*65,536 is sent to the chipset (98,304). Alternatively to set the gear ratio as -11.39 to 1 the value -11.39*65,536 is sent (746,455 dec. or fff49c29 hex.).

In this profile mode, the host specifies one parameter, the gear ratio. The target position is generated by applying the specified gear ratio to the current position of another axis, slaving the driven axis to the axis providing the position input. The following figure shows the arrangement for encoders and motor drives in a typical electronic gearing application.

Representation & Range Units

signed 32 bits* (1/2

scaling)

-1,073,741,824 to +1,073,741,823

Motor

Slave

Encoder

Amplifier

Typically the master axis is only used for encoder input. It is possible however to use the master axis as a normal driven axis by leaving it enabled, and using one of the three trajectory modes other than electronic gear for the master axis. The net effect of this will be to run two servo motors off of the same trajectory profile (although at a different ratio if so programmed).

This configuration is shown in the previous diagram as 'optional' components. Using this configuration the chipset can be made to perform useful functions such as linear interpolation of two axis.

There are no restrictions on changing the gear ratio when the axis is in motion, although care should be taken to select ratios such that safe motion is maintained.

The specified gear ratio (SET_RATIO command) indicates the number of target counts generated per input encoder count. For example a gear ratio of 1.5 means 1.5 counts of the slave axis are generated for every count of the master axis.

There are also no restrictions on changing t o this profile mode while the axes is in motion.

Trajectory Control

Normally each of the above trajectory modes will execute the specified trajectory, within the specified parameter limits, until the profile conditions are satisfied. For example for the point-to-point profile modes this means that the profile will move the axis until the final destination position has been reached, at which point the axis will have a velocity of zero.

MC1401A

Amplifier

Motor

Master

Encoder

Optional

Because a geared axis takes up two encoder channels, the total number of geared axes supported per chipset is 1/2 the total # of axes.

Halting The Trajectory

In some cases however it is necessary to halt the trajectory manually, for safety reasons, or simply to achieve a particular desired profile. This can be accomplished using one of two methods; abrupt stop, or smooth stop.

Abrupt stops are accomplished using the STOP command. This command instantaneously stops the trajectory generator by setting the velocity of the axis to zero. This control mode is typically used during an emergency stop, when no deceleration phase is desired.

Smooth stops are accomplished using the SMOOTH_STOP command. This command causes the trajectory to decelerate at a rate equal to the specified acceleration rate, until a velocity of zero is reached. In

addition the form of the deceleration is symmetric to the acceleration phase. For example if the profile mode is S-curve, and a SMOOTH_STOP command is given, the profile will decelerate in a manner exactly equal and opposite to the acceleration phase.

The STOP command functions in all profile modes; S-curve pointto-point, Trajectory point-to-point, Velocity Contouring, and Electronic Gear.

The SMOOTH_STOP functions in S-curve point-to-point, Trajectory point-to-point, and Velocity Contouring profiling mode. It does not function in Electronic Gear mode.

Caution should be exercised when using the STOP command due to the large and abrupt changes in motion that may occur.

Motion Complete Status

The motion complete and in-motion bits indicate the state of the trajectory generator, not the actual motor. Even if the trajectory generator has completed a motion, the actual axis position may or may not be at rest depending on servo lag, stability, and other system conditions.

Digital Servo Filtering

A digital filter is available for use in calculating a motor output signal. The filter used is a PID (proportional, integral, derivative) filter, along with a velocity feedforward term and a term to adjust the offset, also called the DC bias value. This filter type is known as a PID+Vff filter.

This filter uses programmable gain values which can be tuned to provide excellent control accuracy and stability over a large range of systems.

To simplify the programming of a complete motion system it is convenient to have the motion chipset indicate when a particular profile move has been completed.

This function is provided by two status bits in the chipset's status word (See the section of this manual entitled "Axis Status " for more information on the axis status word). These two bits are called the motion complete bit, and the in-motion bit.

The motion complete bit is controlled interactively by the chipset and the host. After a motion has completed, the chipset sets the motion complete bit on. The host may then poll this bit to determine that motion is complete, or if desired, the host can program the chipset to automatically signal when the motion is complete (using an interrupt). In either case once the host has recognized that the motion has been completed the host clears the motion complete bit, enabling the bit to indicate the end of motion for the next move.

The following list shows the conditions that will cause the motion complete bit to occur:

- Profile has reached the destination position (point-to-point profile modes only)

- Axis trajectory reaches a velocity of zero and the current velocity command is zero

- SMOOTH_STOP command is given and axis trajectory reaches a velocity of zero

- STOP command is given

- Limit switch condition occurs

The in-motion bit is similar to the motion complete bit except that it continuously indicates the status of the axis without interaction with the host. In addition this bit is used exclusively for polled mode operations. It can not cause an interrupt to the host to be generated.

The motion complete and the in-motion indicator bits function in the S-curve point-to-point, Trapezoidal point-to-point, and Velocity Contouring profile modes only. They do not function when the profile mode is set to electronic gearing.

The following schematic diagram shows the computational flow for the PID+Vff digital filter.

Target

Velocity

Proportional Term

P = En * Kp

Bias

Kvff

Target

Position

Integral Term I = (S+En)*Ki

S = S+En

Derivative Term

D = (En-E(n-1))*Kd

Actual Position

From Encoder

In the PID+Vff filter, the host-specified parameters are: Symbol Name Representation & Range

Kp Proportional Gain unsigned 16 bits (0 to 32767) Ki Integral Gain unsigned 16 bits (0 to 32767) Kd Derivative Gain unsigned 16 bits (0 to 32767) Ilim Integration Limit unsigned 16 bits (0 to 32767) Kvff Velocity Feedforward

gain

MtrBias DC motor offset signed 16 bits (-32767 to 32767) The PID+Vff filter is calculated as follows: Position Errorn = En = TPn - AP

Outputn = En*Kp + (En-E + MtrBias

n-1

unsigned 16 bits (0 to 32767)

)*Kd + Int(En)*Ki/256 + TrgtVel*Kvff/4

Output

To Motor

where: En is the position error at sample time n

TPn is the target position at sample time n APn is the actual position at sample time n Int(En) is the integration sum at time sample n TrgtVel is the current desired velocity in counts/sample

MtrBias is the motor bias value

All multiplied error quantities are saturated to fit within a 16 bit number so that no discontinuities in the output signal occur at values beyond +/-

2 15. The integral term is actually maintained to an accuracy of 24 bits, but only the top 16 bits are used. This results in a more useful range for Ki, the integral gain.

The result of this calculation is a 16 bit number. The top 11 bits of this result become the output value if the motor output mode is PWM (1 bit sign, 10 bits magnitude and the entire word is used if the mode is DAC16.

Care should be taken when setting a Ki value for the first time. If the system has already been running and the integration value is unknown, an abrupt 'jump' may occur when the Ki value is set to a non-zero value. To avoid this set the I_LM (integration limit) to 0, set the Ki to the desired value, and then set I_LM to the desired integration limit value. This will 'clear' all prior integration values, smoothly enabling the integration function from that point forward.

The motor bias value is applied to the filter value at all times when the chipset is in closed loop mode. If the chipset transitions to open loop mode (MTR_OFF command is given or a motion error occurs with automatic motor stop enabled) than the motor bias value will be output to the motor by itself, until a manual motor command value is given (SET_MTR_CMD command), at which point this host-provided motor command value, without modification by the motor bias value, becomes the active motor command.

The following example illustrates this: If the chipset is in closed loop mode with a motor bias value of 100, then if a motor off command is given (MTR_OFF), then the output motor command will be exactly 100. Thereafter if the host sends a manual motor command of 200 (using the SET_MTR_CMD command), then the output motor command will be

200. At this instant the chipset is returned to closed loop mode however (MTR_ON command), the motor bias value will again be added to the filter output.

If the specified motor bias value does not properly compensate for the offsetting DC load, then after a motion error with automatic motor stop enabled or after a MTR_OFF command the axis may move suddenly in one direction or another. It is the responsibility of the host to select a motor bias value such that safe motion is maintained.

Parameter Loading & Updating

Motor Limit

In addition to setting various PID gain values the MC1401A also allows the maximum value output by the filter to be set. This motor limit value is set using the command SET_MTR_LMT. It can be read back using the command GET_MTR_LMT.

The specified motor limit affects the filter output such that if the magnitude of the filter output value (positive as well as negative) exceeds the motor limit than the output value is maintained at the motor limit value. Once the filter output value returns below the specified limit than normal servo filter values are output

The motor limit is only applied during closed loop servo operations, when the servo filter controls the motor output value. It does not affect the output motor value applied during open loop operations

Motor Bias

When using an axis which has a net force in one direction or the other (such as a vertical axis which experiences the force of gravity) the motor bias function of the PID compensation filter may be useful. By adding a constant bias value to the filter output, the overall position error of the filter can be reduced by directly compensating for the constant force.

Various profile & servo parameters must be specified by the host for an axis to be controlled in the desired manner. To facilitate precisely synchronized motion, these parameters and related control commands are loaded into the chip using a double-buffered scheme. In this scheme, the parameters and action commands being loaded are not acted upon (copied from the double-buffered to the active registers) until an update signal is given.

This update signal can consist of either a "manual" update command, or one of several conditional breakpoints. Whichever update method is used, at the time the update occurs, all of the double buffered registers and commands will be copied to the active registers. Conversely, before the update occurs, loading the double-buffered registers or executing the double buffered commands will have no effect on the system behavior.

The double buffered registers are listed below.

The motor bias value is set using the command SET_MTR_BIAS. It can be read back using the command GET_MTR_BIAS.

destination position SET_POS maximum velocity SET_VEL acceleration SET_ACC maximum acceleration SET_MAX_ACC jerk SET_JERK ratio SET_RATIO Kp SET_KP Ki SET_KI Kd SET_KD Kvff SET_KVFF Integration limit SET_I_LM

The double-buffered commands are: STOP, SMOOTH_STOP, and SYNCH_PRFL.

Manual Update

There are two methods of manually updating the double-buffered parameters, one for a single axis instantaneous update and one for a multiple-axis update.

The single axis instantaneous update, which is specified using the UPDATE command, forces the parameters for the current axis to be updated at the next servo loop.

The multiple axis instantaneous update, which is specified using the MULTI_UPDATE command, causes multiple axes to be updated simultaneously. This can be useful when synchronized multi-axis profiling is desired. This command takes a 1 word argument which consists of a bit mask, with 1 bit assigned to each axis. Executing this command has the same affect as instantaneously switching to each desired axes, and executing an UPDATE command.

generator) equals or exceeds the specified breakpoint value. This breakpoint is set using the SET_POS_BRK command.

Negative Target Position Breakpoint:.

A 32 bit position breakpoint can be specified which will result in the parameters being updated when the current target position (the instantaneous desired axis position output from the profile generator) equals or is less than the specified breakpoint value.This breakpoint is set using the SET_NEG_BRK command.

Positive Actual Position Breakpoint

A 32 bit position breakpoint can be specified which will result in the parameters being updated when the current actual position (the instantaneous position of the actual axis hardware) equals or exceeds the specified breakpoint value.This breakpoint is set using the SET_ACTL_POS_BRK command.

Negative Actual Position Breakpoint:.

A 32 bit position breakpoint can be specified which will result in the parameters being updated when the current actual position (the instantaneous position of the actual axis hardware) equals or is less than the specified breakpoint value.This breakpoint is set using the SET_ACTL_NEG_BRK command.

Time Breakpoint

A 32 bit time break point can be specified which will result in the parameters being updated when the # of servo loops executed since chip set reset (the current chip set time) is equal to the time breakpoint value.The # of servo loops continuously increases

until it rolls over from 232 - 1 back to 0.The time breakpoint is set using the SET_TIME_BRK command.

Motion Complete Breakpoint

A breakpoint can be specified which will result in the parameters being updated when the previous motion has been completed (motion complete bit is set). When using this breakpoint no 32 bit compare value is required.

Breakpoints

A breakpoint is a convenient way of programming a profile or filter change upon some specific condition. There are two types of breakpoints, those that have a 32-bit comparitor value associated with them and those that do not. For those that have the comparitor, a 32-bit comparitor value is loaded into the breakpoint compare register first, and then one of the breakpoint conditions is specified. For those breakpoint modes without associated comparitor values only the breakpoint condition needs to be specified.

The double-buffered registers and commands will be updated upon satisfaction of the specified breakpoint condition.

Here is a list of all of the available breakpoint conditions. Positive Target Position Breakpoint

A 32 bit position breakpoint can be specified which will result in the parameters being updated when the current target position (the instantaneous desired axis position output from the profile

External Breakpoint

A breakpoint can be specified which will result in the parameters being updated when the home signal of the corresponding axis becomes active (low). When using this breakpoint no 32 bit compare value is required. This breakpoint is useful whenever it is desired that an external signal starts, stops, or otherwise modifies the profile movement.

Normally, whenever one of these conditions has been programmed and the condition occurs, the double-buffered parameters will automatically be shifted to the active registers. There is a mechanism to disable this "automatic update upon breakpoint" however. This is discussed in the next section.

The above breakpoint modes are particularly useful during multi-axis motion. This is because the next profile commands (set of hostspecified trajectory commands) can be pre-loaded and activated at the precise position or time required, with no delay incurred to send an update or load parameters command.

After a breakpoint condition has been satisfied it is no longer active. To set up another breakpoint condition, a new one must be explicitly set by the host.

The double-buffered registers that are shifted to the active registers do not change upon being shift ed, only the act ive registers change.

Disabling Automatic Profile Update

Normally, when a breakpoint condition has been satisfied, it causes the profile & filter parameters to be automatically updated. For certain types of profiles however, it may be desirable to still use the breakpoint mechanism (to allow it to generate a host interrupt for example), but not to have the profile update.

Except for the MULTI_AXIS command, parameter loading and updating is controlled individually for each axis. In addition each axis has a separate 32-bit breakpoint register, and can be set to various individual breakpoint conditions.

External Breakpoints and Homing

By connecting a home input sensor to the home signal input of the MC1401-series chipsets it is possible to cause the chipset to halt a motion at the moment it receives the home signal. This capability makes it ideal for performing a home sequence. The following host I/O sequence illustrates this:

GET_HOME ; check to make sure axis not already at

; home. If so, then a 'reverse' move must ; be made to retract axis from home switch. ; This 'reverse' sequence is not indicated

; here for simplicity sake SET_CAPT_HOME ; set trigger capture to home signal CLR_STATUS ; clear status register GET_CAPT ; clear out any previous captures SET_POS 12345 ; load home move parameters SET_VEL 23456 SET_ACC 345 UPDATE ; start home move SET_EXT_BRK ; initiate external breakpoint mode SMOOTH_STOP ; load (but do not update) a stop command

This sequence will start a homing move which will come to a smooth stop as soon as the axis encounters the home switch. In addition the capture register will be loaded with the exact location of the home sensor. This register can be used in conjunction with the GET_ACTL_POS and SET_ACTL_POS commands to set the position to any desired location. For example if it is desired that the home sensor be located at a position of 0, then the new position should be set to the current actual axis position minus the capture position. This is shown in the sequence below, which should be executed after the axis has come to a stop.

current_pos = GET_ACTL_POS capture_pos = GET_CAPT SET_ACTL_POS (current _pos - capture_pos)

As is the case for all of the breakpoint modes, the external breakpoint can not only be used to stop an ongoing move, but to start or otherwise modify a move as well. This flexibility makes it well suited for applications such as cut-on-the-fly or other externally-initiated motions.

Whether the profiles are automatically updated or not for a given axis is controlled by the commands SET_AUTO_UPDATE_ON and SET_AUTO_UPDATE_OFF. When auto update is set to on, the breakpoint/profile mechanism behaves as described above. When set to off, upon a breakpoint condition, no profile update will occur. When in this mode the only way to update the profile is to use the UPDATE command or the MULTI_UPDATE command.

Travel Limit Swit ches

The MC1401-series chipsets support motion travel limit switches that can be used to automatically recognize an "end of travel" condition.

The following figure shows a schematic representation of an axis with travel-limit switches installed, indicating the "legal" motion area and the over-travel regions.

negative limit

switch

negative

over-travel

region

There are two primary services that the MC1401A provides in connection with the over-travel limit switch inputs:

1) The host can be automatically notified that an axis has entered an over-travel condition, allowing the host to take appropriate special action to manage the over-travel condition.

2) Upon entering an over-travel condition, the trajectory generator will automatically be halted, so that the motor does not travel further into the over travel region.

To recover from an over-travel condition the corresponding status bits in the status word should be reset (see the section of this manual on axis status for details on resetting status word bits). Once this has been performed the host can command a trajectory move to bring the axis out of the over-travel region.

The over-travel detector is 're-armed' when the axis exits the over travel condition.

Only one over-travel signal can be processed at a time. For example if the negative over travel switch becomes active, the corresponding status bits must be cleared, and the axis moved

Legal travel region

positive limit

switch

positive

over-travel

region

into the legal travel range before a positive over travel switch will be recognized.

Motion Error Detection and Recovery

Axis Timing

Each of the axes on the MC1401-series chipsets can be individually enabled or disabled *. Each enabled axis receives a "time slice" of the available computation power of the CP chip.

Under certain circumstances, the actual axis position may differ from the target (desired) axis position by an excessive amount. Such an excessive position error often indicates a potentially dangerous condition such as motor or encoder failure, or excessive mechanical friction.

To detect this condition, thereby increasing safety and equipment longevity, the MC1401A includes a programmable maximum position error.

The maximum position error is set using the command SET_POS_ERR, and read back using the command GET_POS_ERR. To determine whether a motion error has occurred the maximum position error is continuously compared against the actual position error. If the maximum position error value is exceeded, then the axis is said to be in "motion error". When this occurs the motion error bit in the axis status word is set, and the axis motor may be turned off, depending on the state of the automatic motor shutdown mode (see SET_AUTO_STOP_ON and SET_AUTO_STOP_OFF host command descriptions).

At the moment motion error occurs several events occur simultaneously. The following list describes these events:

- Motion Error bit of the axis status word is set

- If automatic motor stop is enabled the motor is set off (set to open loop control mode)

- If the automatic stop is enabled the trajectory generator is stopped

If the automatic motor stop mode is not set than only the motion error status bit is set.

Recovering From A Motion Error

To recover from a motion error which results in the motor being turned off, the following sequence should be performed:

1) Determine cause of motion error and correct problem (this may require human intervention).

2) Turn motor on using MTR_ON command.

* This is true even for the MC1101A, which has only one axis, although generally disabling the only axis has no utility.

Disabled axes do not use any computing power; thus it is possible to increase the servo loop rate when less than the supported number of axes are used.

To set the servo loop rate to a value other than the default value, use the command SET_SMPL_TIME. The value GET_SMPL_TIME can be used to read this value back from the chipset.

The formula for determining the minimum loop time (maximum sampling frequency) for a given number of enabled axis is 100 uSec for each enabled axis.

The following table summarizes the minimum loop time for the standard and -P parts.

# Axes enabled

4 400 3 300 2 200 1 100

The loop time is specified to the chip set as an integer number from 1 to 32,767 with units of 100 uSec For example to set the standard MC1401A part for the minimum loop time with two axes enabled, a value of 2 (2*100 = 200 uSec) would be sent to the chipset using the SET_SMPL_TIME command.

Changing the loop time to increase servo loop rate when axes are disabled is not required. It is avail able as an option if greater loop speed is desired.

The servo loop rate should generally not be changed while axes are in motion.

It is the responsibility of the host to insure that the servo loop rate that is commanded can be supported for the # of axes enabled. Failure to observe the maximums specified in the above table may result in unexpected axis behavior.

Minimum time

After the above sequence, the axis will be servoing correctly, and the profile generator will be at rest, ready for another move.

Host Communications

read or write, this signal will go busy. It will return to ready when the chipset can receive another I/O operation.

Electrical Interface

The MC1401A communicates to the host processor via an 8-bit bidirectional data port. 5* additional signals are used to synchronize communication operations. The following table gives a brief description of the control signals used during host communication:

Signal Description ~HostSlct Selects the host port for operations ~HostWrite Writes a byte of data (or a command) to the chip

set. A write operation can only occur when the ready/busy line indicates ready

~HostRead Reads a byte of data from the chip set. A read

operation can only occur when the ready/busy line indicates ready

HostCmd Is asserted in combination with the HostWrite signal

when a command is being written to the chip set.

HostRdy Indicates to the host that the host port is available

for operations

*An additional signal, HostIntrpt is provided to the host. This signal is not used directly in communication operations, and is discussed in a separate section

Three types of hardware communication operations are possible between the host processor and the chip set; Command Write, Data Write and Data Read. Each of these operations transfers information to or from the chip set, and is coordinated using the 5 control signals listed above.

Command Write

command to the chip set. To perform a write command operation, the desired command is loaded on the 8 data pins and ~HostSlct and ~HostWrite are brought low, while HostCmd is brought high.

operation involves the transfer of a single byte

For more specific electrical information on the host interface operations, see the pin descriptions and the timing diagram.

Packet Format

All communications to/from the chip set take the form of packets. A packet is a sequence of transfers to/from the host resulting in a chip set action or data transfer. Packets can consist of a command with no data (Dataless Command), a command with associated data that is written to the chip set (Write Command) or a command with associated data that is read from the chip set (Read Command).

All commands with associated data (read or write) have either 1 or 2 words of data. See the host commands section for more information on the length of specific commands.

If a read or a write command has 2 words of associated data (a 32 bit quantity) the high word is loaded/read first, and the low word is loaded/read second.

The following charts show the generic command packet sequence for a Dataless Command, a Write Command, and a Read Command. The hardware communication operation described in the previous section to accomplish each type of transfer is shown in the left column.

Dataless Command Time --> --> --> --> Cmd Write:

Data Write: Data Read:

Cmd byte

[pkt checksum]

Data Write

word) to the chip set. To transfer the first byte (high byte), the desired data byte is loaded on the 8 data bits and ~HostSlct, ~HostWrite and HostCmd are brought low. The HostWrite signal is then brought high to end the transfer of the first byte. To transfer the second byte (low byte), the desired data byte is loaded on the 8 data bits and ~HostSlct, ~HostWrite and HostCmd are again brought low.

Data Read

word) from the chip set to the host. To transfer the first (high) byte, ~HostSlct, ~HostRead,and ~HostCmd signals should be brought low, and the data should be read from the 8 bit data bus. The HostRead signal is then brought high to end the transfer of the first byte. To transfer the second (low) byte, ~HostSlct, ~HostRead, and ~HostCmd are again brought low and the data should be read from the data bus.

Before any command write, data write or data read operations are performed, the user must check that the HostRdy signal indicates ready. After a command write, or after the second byte of each

operation involves the transfer of two bytes of data (1

Write Command Time --> --> --> --> Cmd Write:

Data Write: Data Read:

Time --> --> --> -> Cmd Write:

Data Write: Data Read:

Indicates an optional operation

[ ]

Cmd byte

word 1 [word 2]

Read Command

Cmd byte

Word 1 [Word 2] [pkt checksum]

[pkt checksum]

Packet Checksum

The above charts show that at the end of each packet, a checksum word is available for reading.

Although host to chip set I/O operations are extremely reliable, for critical applications the checksum can prov ide a further reliability enhancement (particularly in very noisy electrical environments, or when the communication signals are routed over a media that may have data losses such as a serial link).

This checksum consists of a 16-bit sum of all previous communications that have occurred for the associated command. The command byte is included in the low byte of the 1st checksum word (high byte set to 0). Data words are added as is to the checksum value.

For example if a SET_VEL command (which takes two 16-bit words of data) was sent with a data value of fedcba98 (hex), the checksum would be:

0011 (code for SET_VEL command) + fedc (high data word) + ba98 (low data word)

---------1b985 check sum = b985 (keep bottom 16 bits only)

The following list indicates the command sequences that result in a command error:

- Changing and updating the acceleration (SET_ACC, UPDATE) when in the trapezoidal profile mode and when the axis trajectory is still in motion.

- Changing and updating either the velocity, max acceleration, or jerk (SET_VEL or SET_MAX_ACC or SET_JERK, and then UPDATE) when in the S-curve profiling mode and when the trajectory is in motion

- Commanding a move in the same direction as a limit switch condition when in Trapezoidal or S-curve profile mode. For example if travelling in the positive direction and a limit switch is encountered, a further move in the positive direction will be ignored and a command error will be generated.

Once a command error occurs the command error bit is set, and the illegal profile changes are ignored. If additional parameters are also changed such as position or any filter values as part of the same UPDATE command then these parameters will not be rejected at the time of the UPDATE, and they will become the active values.

Axis Addressing

Reading the checksum is optional. Recovering from an incorrect packet transfer (bad checksum) will depend on the nature of the packet. Read and Write operations can always be re-transmitted, while a command resulting in an action may or may not be re-tried, depending on the command and the state of the axis.

Illegal Commands

When the MC1401A receives a command that is illegal (see host command summary for listing of illegal commands), it will signal this condition by returning a checksum of 0, regardless of the illegal command value or the value of any subsequent data written to the host as part of the illegal command sequence.

In this manner the host processor checksum can be used to detect communication problems as well as an illegal command sequence, resulting in a simplification of the host processor communication code.

Command Errors

If a command, or command sequence is sent to the chipset that is not valid at a given operating condition of the chipset, but is valid at other times, this command is said to cause a command error.

When a command error occurs this condition is indicated by the 'command error' bit of the axis status word (See the section of this manual entitled "Axis Status" for more information on the axis status word).

Most chip set commands alter the parameters or the operating state of one axis at a time. In this way each axis can be controlled separately. To facilitate efficient communication for these types of commands, the chip set maintains the concept of a current axis number, which can be set explicitly by the host. After setting the current axis number, commands that are addressed to the current axis will automatically operate on this axis. The current axis number will stay the same until it is changed by one of the commands that alter the current axis number.

As an illustration of this, the following sequence sets the current axis to #3, updates some motion parameters, and switches to axis #1, and alters some other motion parameters.

SET_3 SET_POS 02345678

UPDATE -

SET_1 SET_ACCEL 00001234

UPDATE -

-> sets current axis to #3

-> loads current axis (#3) dest. position with value of 2345678

> causes the loaded value to take

effect (axis # 3)

-> sets current axis to #1

-> loads current axis (#1) with acceleration value 1234

> causes the loaded value to take

effect (axis # 1)

Axis Status

set by the chipset, and must be reset by the host (They will not be cleared by the chipset).

The MC1401A supports a status word for each axis, which contains various information about the state of the axis.

The status word is a 16-bit register which can be queried using the command GET_STATUS. It contains the following information (Bit encoding is 0 = LSB, 15 = MSB):

Bit # Description 0 Motion complete flag. This bit is set (1) when the axis

trajectory has completed. This flag is only valid for the Scurve and trapezoidal, and velocity contouring profile modes.

1 Wrap-around condition flag. This bit is set (1) when the axis

has reached the end of its travel range,and has wrapped to the other end of the travel range. Specifically, when travelling in a positive direction past the position +1,073,741,823, the axis will wrap to position 1,073,741,824, and vice-versa.

2 Breakpoint reached flag. This bit is set (1) when one of the

breakpoint conditions has occurred.

3 Index pulse received flag. This bit is set (1) when an index

pulse has been received.

4 Motion error flag. This bit is set (1) when the position error is

exceeded (see filter section for more information). This bit can only be reset when the axis is no longer in a motion error condition

5 Positive limit switch flag. This bit is set (1) when the positive

limit switch goes active.

6 Negative limit switch flag. This bit is set (1) when the

negative limit switch goes active.

7 Command error flag. This bit is set (1) when a command

error has occurred.

8 motor on/off status (1 indicates motor is on, 0 indicates

motor is off). 9 axis on/off status (1 indicates on, 0 indicates off). 10 In-motion flag. This bit continuously indicates whether or not

the axis trajectory is in motion. This bit is set (1) when the

axis is in motion, and cleared (0) when the axis trajectory is

not in motion. 11 reserved (may contain 0 or 1) 12,13 current axis # (13 bit = high bit, 12 bit = low bit). Therefore

axis encoding is as follows:

Bit 13 Bit12 Axis

001

012

103

114 14,15 reserved (may contain 0 or 1)

Bits 8-10 and 12-13 indicate continuous status information, and do not need to be reset by the host.

Bits 0-7 of the status word indicate various status flags that can also generate host interrupts (see next section for details). These flags are

Bits 0-7 of the status word operate using a set/reset mechanism. These flags are set by the chipset, and must be reset by the host. If they are not reset by the host they will remain active indefinitely.

Miscellaneous Mode Status Word

There is another status word available that indicates the current status of various mode settings or conditions.

The miscellaneous mode status word is a 16-bit register which can be queried using the command GET_MODE. It contains the following information (Bit encoding is 0 = LSB, 15 = MSB):

Bit # Description 0-6 Used internally by chipset. Contains no host-useable

information.

7 Stop on motion error mode flag. This bit indicates the state

of the stop on motion error mode, set by the commands SET_AUTO_STOP_ON and SET_AUTO_STOP_OFF. A 1 indicates auto stop is on.

8-9 Used internally by chipset. Contains no host-useable

information.

10 Auto update flag. This bit indicates the state of the auto

update mode, set using the commands SET_AUTO_UPDATE_ON and SET_AUTO_UPDATE_OFF. A 1 indicates that auto update is disabled.

11,12 Trajectory generator mode. This bit indicates the mode of

the trajectory generator, set using the commands SET_PRFL_S_CRV, SET_PRFL_TRAP, SET_PRFL_VEL, SET_PRFL_GEAR. The encoding is as follows: Bit 12 Bit11 Profile Mode 0 0 trapezoidal 0 1 velocity contouring 10s-curve 1 1 electronic gear

13-15 Phase #. These bits indicate the current phase # of the S-

curve profile (only valid if the current profile mode is Scurve). A 0 indicates that the profile has not started yet, and phases 1-7 indicate the phase #'s corresponding to the phases described in the S-curve profiling mode. The 3-bit phase # word is encoded bit 15 MSB, and bit 13 LSB.

Host Interrupts

In many situations, during axis motion or at other times, it is useful to have the chip set signal the host that a special condition has occurred. This is generally more convenient and efficient than having the host poll the chip set for various possible conditions. This chip set-initiated signal is known as a host interrupt.

Several chip set conditions may occur that can result in the generation of a host interrupt. Whether these conditions in fact interrupt the host is controllable for each condition and for each axis. The mechanism used to control each condition is a mask register.

The interrupt conditions correspond to bits 0-7 of the status register (the axis event flags), described in the previous section. These conditions are summarized below:

Motion Complete Occurs when the profile is complete Wrap-around condition Occurs when the axis position wraps. Break Point Reached Occurs when a breakpoint condition has

been satisfied. Position Capture Received Motion Error Occurs when the maximum position

Negative Limit Switch Occurs when the negative over-travel

Positive Limit Switch Occurs when the positive over travel

Command Error Occurs when a host communication

Occurs when the encoder index pulse or

home pulse has been captured

error set for a particular axis has been

exceeded

limit switch is active

sequence causes a command error

condition

SET_INTRPT_MASK Sets the interrupt conditions mask GET_INTRPT Returns the status of the interrupting axis

(including the interrupting axis #). The current axis # is not altered by this command

SET_I Changes the current axis # to the

interrupting axis. This is a 'time saver' command which performs the dual operations of getting the interrupting axis # and switching to that axis in one command.

RST_INTRPT Clears particular conditions for the

interrupting axis. The current axis # is not altered by this command.

To facilitate determining the nature of the interrupt, the status register holds the axis #, allowing the interrupting axis # to be determined.

The following represents a typical sequence of interrupt conditions and host responses. Assume for the purposes of this example that an axis (not the current axis) has hit a "hard stop" causing an essentially instantaneous motion error, as well as a positive limit switch trip. Also assume that the interrupt mask for this axis was set so that either motion errors or limit switch trips will cause an interrupt

When one of these interrupt conditions occur for a particular axis, the host interrupt line is made active. At this point the host can respond to the interrupt (although the current I/O operation should be completed), but it is not required to do so

When the host has completed processing the interrupt, it sends a command that clears the interrupt conditions for a particular axis, the RST_INTRPT command.

This command includes a "clearing mask" as an argument, which allows one interrupt to be cleared at a time.

Bits cleared by the RST_INTRPT command are the exact same bits as those cleared by non-interrupt commands such as RST_STATUS and CLR_STATUS. In each case the bits affected are the status word bits 0-7.

Interrupts occur for a particular axis. If the user is currently programming parameters on axis #1 and an interrupt occurs on axis #3, it is the host's responsibility to change axis number to 3 if this is the appropriate response to an interrupt on that axis. If more than one axis interrupt condition becomes active at exactly the same time, then the axis with the lowest number will generate the interrupt first.

The following host commands are used in managing interrupts: (See Host Command reference for complete information)

Event Host action

motion Error & limit switch trip generates interrupt interrupting axis status returned by chipset, current axis set to interrupting axis.

chipset clears motion error bit and disables host interrupt line Because limit switch interrupt is still active chipset immediately generates interrupt for limit switch interrupting axis status returned by chipset, current axis set to interrupting axis.

chipset clears limit switch bit and disables host interrupt line

At the end of this sequence, all status bits are clear, the interrupt line is inactive, and no interrupts are pending.

host sends SET_I command

host detects motion error & limit switch flags are set, recovers from motion error first.

host sends: RST_INTRPT 00EF, clearing motion error bit

host sends SET_I command

host detects that neg. limit switch trip flag is set, performs recovery for limit switch trip.

host sends RST_INTRPT 00DF, clearing pos. limit switch bit

Note that it is not required to process multiple interrupts separately (as is shown in the example). It is perfectly valid to process 2 or more interrupt conditions at the same time, and to then send a RST_INTRPT command with a mask that clears multiple bits at the same time.

The RST_INTRPT and GET_I commands are only effective when there is an interrupt present. If no interrupt is present than alternative 'polled-mode' commands such as RST_STATUS or GET_STATUS should be used.

Although this digital filtering scheme can dramatically increase the overall reliability of the quadrature data, to achieve the highest possible reliability additional techniques may be required, such as differential line drivers/receivers, or analog filtering. Whether these additional schemes are required depends on the specific system, and the amount and type of noise sources.

Encoder Position Feedback

The MC1401-series of chipsets support two modes for inputting motor position information to the chipset, although they are supported in separate chipset products These modes are listed below:

- Incremental encoder (standard parts)

- parallel-word device (-P parts)

To operate the MC1401A in one encoder mode or another, the correct part # must be installed.

Incremental Encoder Input

For standard (no dash) parts an incremental encoder is used for input. In this mode four position input and control signals are supported:

- A quadrature channel

- B quadrature channel

- Index pulse

- Home signal

Each quadrature channel consists of a square wave offset 90 deg. from the other. Positive motion consists of the A channel leading the B channel by 90 deg., and negative motion consists of the A channel lagging the B channel by 90 deg. For each full phase of one channel, four resolved quadrature counts will occur, resulting in a 4 to 1 resolution enhancement over the basic channel resolution.

The index pulse is typically located on the encoder and will be active once per revolution. The chip set recognizes that an index has occurred (i.e. when the 32-bit index location is captured) when the index signal transitions low, followed by the A, B channels transitioning low.

Encoder Filtering

To enhance reliability of the received encoder information the MC1401A provides digital filtering of the quadrature data lines (A and B quadrature count) as well as the index and home signals.

For all of these signals a valid high or low condition is recognized only when the condition has been maintained for 3 clock cycles of 160 nSec each (total required duration of 480 nSec)

High Speed Position Capture

Each axis of the MC1401A supports a high speed position capture register that allows the current axis location to be saved using an external trigger signal. When in incremental encoder mode, The MC1401A allows either the index signal or the home signal to be used as the capture trigger. These two input triggers differ however in that the index signal will cause a position capture when it, as well as the A and B index signals, transition low, while the home signal will result in a capture when it alone goes low.

The commands SET_CAPT_INDEX and SET_CAPT_HOME select which input signal is used.

After an index or home signal has been captured by the MC1401A, the index value must be read by the host processor before another position capture can occur. In addition, if the index signal is being used as the trigger, the index signal,along with the A and B quadrature signals, must transition high before another index pulse can be registered.

The captured position is equal to the axis position at the moment the trigger pulse was encountered (including other required signal states defined above) +/- 1 count. Note that the capture register is located in hardware. Its accuracy is therefore not affected by the velocity of the axis.

Parallel-Word Device Input

For -P parts, a parallel-word device input mechanism is provided which can be used with a large variety of devices including the following:

- Resolvers (after Resolver to Digital conversion)

- Absolute optical encoders

- Laser interferometers with parallel word read-out

- Incremental encoders with external quadrature decoder circuit

- A/D converters reading an analog feedback signal

In this encoder input mode, the MC1401A reads the encoder position directly through its external bus, and inputs the absolute word as a 16 bit value.

Depending on the nature of the feedback device fewer than 16 bits of resolution may be available, in which case the unused high order data bits should be arranged to indicate a 0 value when read by the MC1401A.

For example if a brief spurious noise signal on one of the lines occurs for 300 nSec, then this noise will be rejected until a valid state change lasting over 480nSec occurs.

The value input by the chipset should be binary coded. The MC1401A assumes that the position data provided by the external device is a twos complemented signed number. If the value returned instead ranges

from 0 to 2n-1 where n is the number of bits provided by the feedback

device than the only difference in behavior will be the interpretation of the start location, which will be 'shifted' by 1/2 the full scale feedback range. If desired this initial position may be altered using the SET_ACTL_POS command.

In addition to supporting position tracking across the full numeric feedback range the MC1401A also provides the ability to support multiturn systems. The MC1401A continuously examines the parallel encoder values being read in, and automatically recognizes an axis "wrap" condition, whether from largest encoder value to smallest encoder value (negative wrap) or from smallest value to largest value (positive wrap).

Using this "virtual" multi turn counter, the MC1401A continuously maintains the axis location to a full 32 bits. Of course if the axis does not wrap around (non multi-turn system), the range will stay within a 16 bit value.

To facilitate the multi-turn mechanism, the host must specify the number of counts per rotation to the chipset. This should be done at setup time using the command SET_CNTS. The actual counts per rotation value specified to the chipset is 1/2 the number of counts per motor rotation. See the Host Command section of this manual for details.

For systems that use a position counter with a modulo smaller than the encoder counts per revolution, set the counts/rev value equal to the position counter size. For example, if a rotary laser interferometer is being used which provides a 16 bit output value, but provides 16,777,216 counts per revolution, use a counts/rev value of 32,768

(216/2)

For the multi-turn mechanism to work properly the axis can not rotate faster than 2,000 revolutions per second. Also, the input word must be binary-coded. Grey-encoded input words, or other encoding formats must be converted external to the chipset.

Parallel-Word Device Interfacing

Signal Name Comments Data0-11 High 12 bits of external data bus signals used to

input position data.

DACLow0-3 Low 4 bits of external data bus signals used to input

position data.

PosSlct Signal set by chipset indicating data is being read

from parallel-word device

DAC16Addr0-1 Axis # address signals set by chipset used to select

correct position input device

Convert 'Start conversion' signal strobed by chipset after all

position data has been input. Typically used to start another A/D conversion cycle so data is ready by next read.

To read a 16-bit word from a parallel-word device, the chipset sets up the DAC16Addr0-1 signals for the selected axis number and brings PosSlct low (selecting the position input operation). The chipset then reads in the 16 bit data word. The chipset then de-asserts PosSlct and any asserted address bits and starts the above cycle again, for up to a total of four axes.

At the end of the position reads the Convert signal is briefly strobed low. This signal is typically used to synchronize external latch hardware, or to start an A/D convert cycle.

For more information on the parallel-word read signal timing & conditions, see the pin descriptions and interface timing diagram.

Although the chipset will attempt to read all of the parallel-word devices whether or not the axis is enabled, unused axes can be left uninterfaced.

The axis read sequence is #1, 2, 4, 3.

No high-speed position capture is supported in the parallel-word device input mode. Therefore the index and home signals, as well as the quadrature A and B signals are unused in this mode.

In the parallel-word position input mode, the following signals are used by the chipset:

Motor Outputs

The MC1401-series of chipsets provides two motor amplifier interfaces:

- 10-bit 24.5 Khz PWM interface

- 16-bit DAC output.

For each chipset the supported output modes are host-selectable. The selected method affects all axes (motor output mode is not individually programmable for each axis). The host commands to select these output modes are SET_OUTPUT_PWM (to select PWM mode) and SET_OUTPUT_DAC16 (to select 16 bit DAC mode).

Motor Output Control

Generator

signal generator

PWM Output

The following diagram shows the control flow for the motor command output by the chipset.

Motor command register

(SET_MTR_CMD)

Trajectory

MTR_OF

MTR_ON

Servo filter

(PID or PIVff)

PWM or DAC

Amp.

Actual position

The chipset can be run in either closed loop mode, or open loop mode. In closed loop mode the motor command is determined by the output of the servo filter, which in turn is determined by the output of the trajectory generator and the actual axis position. Closed loop mode is the normal operating mode of the chipset.

Open loop mode allows the motor command to be directly set by the host. Open loop mode is typically used when one or more axes require torque control only, or to calibrate the amplifier.

Here is a summary of the motor control commands. Command Description

MTR_ON Enables closed loop servo control. In this

mode the source of motor command is the servo filter and the motor command register has no effect on motor output.

MTR_OFF Disables closed loop servo operations

(enables open loop control). In this mode the motor command is determined by the motor command register, which is set by the host.

SET_MTR_CMD Sets the motor command register, used to

control the motor output value during open loop operations. For this command to take effect the motor must be off (MTR_OFF command).

GET_MTR_CMD Retrieves the current motor command output

by the chipset. When in closed loop mode this command will return the current output value of the servo filter. When in open loop mode this command will return the value set using the SET_MTR_CMD command.

When PWM output is selected, the magnitude and sign pins for each axis will continuously reflect the motor amplifier signal being output by the chip set. The sign bit will be active (high) when the motor is driven in the positive direction, and inactive (low) when in the negative direction.

The following figure shows the magnitude output wave forms:

0/1024

(off)

1/1024

(minimum on)

512/1024

(50 % On

1023/1024

> 99% O n

1024/1024

Full On

1 0

16 Bit DAC Output

When 16 bit DAC output is selected, for each active axis, the DAC control pins will continuously load a 16-bit DAC value into the addressed DAC. To load a particular DAC, The DAC address (1 of 4) is output on the signals DAC16Addr0-1, the 16 bits of DAC data are output on pins Data0-11 (high 12 bits), as well as DACLow0-3 (low 4 bits), I/OAddr0-3 and DACSlct are high, and I/OWrite is low. For more information on the DAC signal timing & conditions, see the DAC pin descriptions and interface timing diagram.

DACs with lower resolution than 16 bits can also be used. To connect to a DAC with less resolution, the high order bits of the 16-bit data word should be used. For example, to connect to an 8-bit DAC, bits Data4Data11 should be used. The low order 8 bits are written to, but ignored.

The 16-bit data word that is put out as an unsigned 16-bit number with a range of 0 to 65535. An output value of 0 indicates the largest negative direction motor command, a value of 32768 indicates no motor output, and a value of 65535 indicates the largest positive direction motor command.

NOTES

Command Summary

Command Mnemonic Code

(hex)

Axis Control

SET_1 01 all axes set by cmd. - 1/read Set current axis # to 1 SET_2 02 all axes set by cmd. - 1/read Set current axis # to 2 SET_3 03 all axes set by cmd. - 1/read Set current axis # to 3 SET_4 04 all axes set by cmd. - 1/read Set current axis # to 4 SET_I 08 all axes interrupting axis - 1/read Set current axis # to the interrupting axis

Profile Generation

SET_PRFL_S_CRV 0b all axes current axis no 0 Set profile to S-curve SET_PRFL_TRAP 09 all axes current axis no 0 Set profile to trapezoidal point to point SET_PRFL_VEL 0a all axes current axis no 0 Set profile to velocity-contouring SET_PRFL_GEAR 0c 1, 2 current axis no 0 Set profile to electronic gear SET_POS 10 all axes current axis yes 2/write Set command position SET_VEL 11 all axes current axis yes 2/write Set command velocity SET_ACC 12 all axes current axis yes 2/write Set command acceleration SET_MAX_ACC 15 all axes current axis yes 1/write Set max accel. (S-curve profile only) SET_JERK 13 all axes current axis yes 2/write Set command jerk SET_RATIO 14 1, 2 current axis yes 2/write Set command electronic gear ratio STOP/CLR_PRFL 46 all axes current axis yes 0 Abruptly stop axis trajectory motion SMOOTH_STOP 4e all axes current axis yes 0 Smoothly stop axis trajectory motion SYNCH_PRFL 47 all axes current axis yes 0 Set servo following error to zero GET_POS 4a all axes current axis - 2/read Get command position GET_VEL 4b all axes current axis - 2/read Get command velocity GET_ACC 4c all axes current axis - 2/read Get command acceleration GET_MAX_ACC 4f all axes current axis - 1/read Get max. accel. (S-curve profile only) GET_JERK 58 all axes current axis - 2/read Get command jerk GET_RATIO 59 1, 2 current axis - 2/read Get command electronic gear rate GET_TRGT_POS 1d all axes current axis - 2/read Get current target position GET_TRGT_VEL 1e all axes current axis - 2/read Get current target velocity

Digital Filter

SET_KP 25 all axes current axis yes 1/write Set proportional gain SET_KD 27 all axes current axis yes 1/write Set derivative gain SET_KI 26 all axes current axis yes 1/write Set integral gain SET_KVFF 2b all axes current axis yes 1/write Set feedforward gain SET_I_LM 28 all axes current axis yes 1/write Set integration limit SET_MTR_LMT 06 all axes current axis no 1/write Set motor output limit SET_MTR_BIAS 0f all axes current axis no 1/write Set motor output bias SET_POS_ERR 29 all axes current axis no 1/write Set maximum position error limit GET_KP 50 all axes current axis - 1/read Get proportional gain GET_KD 52 all axes current axis - 1/read Get derivative gain GET_KI 51 all axes current axis - 1/read Get integral gain GET_KVFF 54 all axes current axis - 1/read Get velocity feedforward gain GET_I_LM 53 all axes current axis - 1/read Get integration limit GET_MTR_LMT 07 all axes current axis - 1/read Get motor output limit GET_MTR_BIAS 2d all axes current axis - 1/read Get motor output bias GET_POS_ERR 55 all axes current axis - 1/read Get position error GET_INTGR 2e all axes current axis - 1/read Get integrated position error value GET_ACTL_POS_ERR 60 all axes current axis - 1/read Get actual position error SET_AUTO_STOP_ON 45 all axes current axis - 0 Set auto stop on motion error mode on SET_AUTO_STOP_OFF 44 all axes current axis - 0 Set auto stop on motion error mode off

AvailableonAxes acted on Double

Buffered

data words

/direction.

Description

Command Mnemonic Code

(hex)

Parameter Update

SET_TIME_BRK 17 all axes current axis no 0 Set breakpoint mode to time SET_POS_BRK 18 all axes current axis no 0 Set breakpoint mode to pos. target position SET_NEG_BRK 19 all axes current axis no 0 Set breakpoint mode to neg. target position SET_ACTL_POS_BRK 1b all axes current axis no 0 Set breakpoint mode to pos. actual position SET_ACTL_NEG_BRK 1c all axes current axis no 0 Set breakpoint mode to neg. actual position SET_MTN_CMPLT_BRK 35 all axes current axis no 0 Set breakpoint mode to motion complete SET_EXT_BRK 5e all axes current axis no 0 Set breakpoint mode to external SET_BRK_OFF 6d all axes current axis no 0 Set breakpoint mode off SET_BRK_PNT 16 all axes current axis no 2/write Set breakpoint comparison value UPDATE 1a all axes current axis - 0 Immediate parameter update MULTI_UPDATE 5b all axes set by mask - 1/write Multiple axis immediate parameter update SET_AUTO_UPDATE_ON 5c all axes current axis no 0 Set automatic profile update on SET_AUTO_UPDATE_OFF 5d all axes current axis no 0 Set automatic profile update off GET_BRK_PNT 57 all axes current axis - 2/read Get breakpoint comparison value

Interrupt Processing

SET_INTRPT_MASK 2f all axes current axis no 1/write Set interrupt mask GET_INTRPT 30 all axes interrupting axis - 1/read Get status of interrupting axis RST_INTRPT 32 all axes interrupting axis no 1/write Reset interrupting events GET_INTRPT_MASK 56 all axes current axis - 1/read Get interrupt mask

Status/Mode

CLR_STATUS 33 all axes current axis no 0 Reset status of current axis RST_STATUS 34 all axes current axis no 1/write Reset events for current axis GET_STATUS 31 all axes current axis - 1/read Get axis status word GET_MODE 48 all axes current axis - 1/read Get axis mode word

Encoder

SET_CNTS 68 all axes current axis no 1/write Set # of counts/motor rotation (-P vrsn only) SET_CAPT_INDEX 64 all axes current axis no 0 Set index signal as position trigger SET_CAPT_HOME 65 all axes current axis no 0 Set home signal as position trigger GET_CAPT 36 all axes current axis - 2/read Get current axis position capture location GET_CNTS 6f all axes current axis - 1/read Get # of counts/motor rotation (-P vrsn only)

Motor

SET_OUTPUT_PWM 3c all axes global no 0 Set motor output mode to PWM SET_OUTPUT_DAC16 3b all axes global no 0 Set motor output mode to 16-bit DAC MTR_ON 43 all axes current axis no 0 Enable motor output MTR_OFF 42 all axes current axis no 0 Disable motor output SET_MTR_CMD 62 all axes current axis no 1/write Write direct value to motor output GET_MTR_CMD 3a all axes current axis - 1/read Read motor output command GET_OUTPUT_MODE 6e all axes global - 1/read Get current output mode

Miscellaneous

AXIS_ON 41 all axes current axis no 0 Enable axis AXIS_OFF 40 all axes current axis no 0 Disable axis SET_ACTL_POS 4d all axes current axis no 2/write Set current actual axis location GET_ACTL_POS 37 all axes current axis - 2/read Get current actual axis location SET_LMT_SENSE 66 all axes global no 1/write Set limit switch bit sense GET_LMT_SWTCH 67 all axes global - 1/read Get state of limit switches LMTS_ON 70 all axes global no 0 Set limit switch sensing on LMTS_OFF 71 all axes global no 0 Set limit switch sensing off GET_HOME 05 all axes global - 1/read Get state of home switches SET_SMPL_TIME 38 all axes global no 1/write Set servo loop sample time GET_SMPL_TIME 61 all axes global - 1/read Get servo loop sample time RESET 39 all axes global no 0 Reset chipset GET_VRSN 6c all axes global - 1/read Get chipset software version information GET_TIME 3e all axes global - 2/read Get current chip set time (# servo loops)

AvailableonAxes acted on Double

Buffered

data words

/direction

Description

Command Reference

Each command consists of a single byte, with a command code value as described in the "encoding" description for each command. Data is transmitted to/from the chip set in 16-bit words. All data is encoded "high to low" i.e. each 16-bit word is encoded high byte first, low byte second, and two word data values are encoded high word first, low word second.

The following hex code commands are reserved for future use, or are currently used during manufacturing/test. They return a valid checksum, although they should not be used during normal chipset operations. The hex command codes are: 49, 4e

The following hex code commands are illegal, and will return a checksum of 0. They should not be used during normal chipset operations. The hex command codes are: 00, 0e, 1f, 20, 23, 24, 2c, 5f, 63, 72 through ff

Signed data is represented in two’s complement format. In the case of 32-bit quantities, the entire 32-bit number is two's complemented. For example to transmit the decimal number 1,234,567, which has a hexadecimal representation of 12d687, the high word is sent first (12 hex) and then the low word is sent (d687 hex). Negative numbers are treated in the same way. For example to transmit the decimal number

-746,455 , which has a hexadecimal value of fff49c29, then the high word is transmitted first (fff4 hex.) followed by the low word (9c29 hex.).

Some chipset quantities such as position are provided with ‘unity scaling’, meaning that the value provided is used by the chipset without internal scaling.

Other chipset quantities are scaled by various constants to allow a more useful operating range. The non-unity scaling constants that are

used by the chipset are either 1/216 or 1/232 .

If 1/216 scaling is used then the chipset expects a number which has been scaled by a factor of 65,536 from the ‘user’ units. For example to specify a velocity (SET_VEL command) of 2.75 counts/sample time,

2.75 is multiplied by 65,536 and the result is sent to the chipset as a 32 bit integer (180,224 dec. or 2c000 hex.). 1/216 scaling is used with 16

bit as well as 32 bit quantities. The size of the data word does not affect how the scaling is performed.

If 1/2

scaling is indicated the chipset expects a number which has

been scaled by a factor of 4,294,967,296. For example to specify a jerk value (SET_JERK command) of .0075 counts/sample time3, .0075

is multiplied by 4,294,967,296 and the result is sent to the chipset as a 32 bit integer (32,212,256 dec. or 1eb8520 hex).

Unless otherwise noted, all numerical values presented in this command summary are in decimal.

Axis Control

SET_1 Set current axis to #1

Data/direction: 1/read Encoding: 01 (hex) Axis acted on: set by command Available on: all axes Double buffered: No

SET_1 changes the current axis number to 1. All commands that operate on the current axis will be affected by this command. The status of axis #1 is returned. See GET_STATUS command for the status word format.

SET_2 Set current axis to #2

Data/direction: 1/read Encoding: 02 (hex) Axis acted on: set by command Available on: all axes Double buffered: No

SET_2 changes the current axis number to 2. All commands that operate on the current axis will be affected by this command. The status of the axis #2 is returned. See GET_STATUS command for the status word format.

All transmissions to/from the chip set are checksummed. The checksum is a 16-bit quantity that can be read at the end of each command transmission. The checksum value consists of the 16-bit sum of all 16-bit transmissions to or from the chip set, including the command byte which occupies the low byte of the first 16-bit transmission word. For example if a SET_VEL command (which takes two 16-bit words of data) was sent with a data value of fedcba98 (hex), the checksum would be:

0011 (code for SET_VEL command) + fedc (high data word) + ba98 (low data word)

---------1b985 check sum = b985 (keep bottom 16 bits only)

SET_3 Set current axis to #3

Data/direction: 1/read Encoding: 03 (hex) Axis acted on: set by command Available on: all axes Double buffered: No

SET_3 changes the current axis number to 3. All commands that operate on the current axis will be affected by this command. The status of the axis #3 is returned. See GET_STATUS command for the status word format.

SET_4 Set current axis to #4

Data/direction: 1/read Encoding: 04(hex) Axis acted on: set by command Available on: all axes Double buffered: No

SET_4 changes the current axis number to 4. All commands that operate on the current axis will be affected by this command. The status of the axis #4 is returned. See GET_STATUS command for the status word format.

SET_I Set current axis to interrupting axis

Data/direction: 1/read Encoding: 08 (hex) Axis acted on: interrupting axis Available on: all axes Double buffered: No

SET_I changes the current axis number to the interrupting axis, which is the axis that has caused the host interrupt to become active. All commands that operate on the current axis will be affected by this command. The status of the interrupting axis is returned. See GET_STATUS command for the status word format.

Profile Generation

SET_PRFL_S_CRV Set profile mode to S-curve point to

point

Data/direction: none Encoding: 0b (hex) Axis acted on: current axis Available on: all axes Double buffered: No

SET_PRFL_S_CRV sets the trajectory profile mode to S-curve point to point. In this mode, the host specifies the destination position (SET_POS cmd), the maximum velocity (SET_VEL cmd) the maximum acceleration (SET_MAX_ACC cmd), and the jerk (SET_JERK cmd). Once in this mode, the trajectory profile generator will drive the axis to the destination position at the specified jerk while not exceeding the maximum velocity and max. acceleration. The axis will stay in this profile mode until another profile mode is explicitly set.

While in this profile mode, no parameters should be changed while the axis is in motion.

Before setting the current profile mode to S-curve point to point, the axis should be completely at rest.

SET_PRFL_TRAP Set profile mode to trapezoidal point to

point

Data/direction: none Encoding: 09 (hex) Axis acted on: current axis Available on: all axes Double buffered: No

SET_PRFL_TRAP sets the trajectory profile mode to trapezoidal point to point. In this mode, the host specifies the destination position (SET_POS cmd), the maximum velocity (SET_VEL cmd) and the acceleration (SET_ACC cmd). Once in this mode, the trajectory profile generator will drive the axis to the destination position at the specified acceleration while not exceeding the maximum velocity. Position and velocity may be changed on the fly when in this profile mode; acceleration may not. The axis will stay in this profile mode until another profile mode is explicitly set.

Before setting the current profile mode to trapezoidal point to point, the axis should be completely at rest.

While in this mode, the acceleration should not be changed until the axis has come to a stop.

SET_PRFL_VEL Set profile mode to velocity contouring.

Data/direction: none Encoding: 0a (hex) Axis acted on: current axis Available on: all axes Double buffered: No

SET_PRFL_VEL sets the trajectory profile mode to velocity contouring. In this mode the host specifies the command acceleration (SET_ACC cmd), and the maximum velocity (SET_VEL cmd). Once in this mode, the trajectory profile generator will drive the axis at the specified acceleration while not exceeding the maximum velocity. The acceleration and the maximum velocity may be changed on the fly. The axis will stay in this profile mode until another profile mode is explicitly set. There are no limitations on changing the profile mode to velocity contouring while the axis is in motion.

There are no host-specified limits on the position in this mode. It is the responsibility of the host to specify profile parameters that maintain the axis within safe position limits.

SET_PRFL_GEAR Set profile mode to electronic gear

Data/direction: none Encoding: 0c (hex) Axis acted on: current axis Available on: axis #1, #2 (see chart) Double buffered: No

SET_PRFL_GEAR, sets the trajectory profile mode to electronic gear. In this mode the host specifies the gear ratio (SET_RATIO cmd). Once in this mode the trajectory profile generator will drive the current (slave) axis to the position specified by the master axis factored by the

specified gear ratio. The gear ratio may be changed on the fly. The axis will stay in this profile mode until another profile mode is explicitly set. The electronic gear mode is available on the following axis for each chipset:

chipset p/n gear pairs (master -> slave) MC1401A #3 -> #1, #4 -> #2 MC1201A #2 -> #1 MC1101A not available

There are no host-specified limits to axis motion in this mode. It is the responsibility of the host to specify a gear ratio that maintains the axis within safe motion limits.

SET_POS Set command position

Data/direction 2/write Encoding: 10 (hex) Axis acted on: current axis Available on: all axes Double buffered: yes

SET_POS sets the final position used during the S-curve and trapezoidal trajectory profile generator modes. The position is specified as a signed 32-bit number with units of counts. The range is

-1,073,741,824 to 1,073,741,823. The loaded position is not utilized until a parameter update occurs.

SET_VEL Set command velocity

Data/direction: 2/write Encoding: 11 (hex) Axis acted on: current axis Available on: all axes Double buffered: yes

SET_VEL sets the maximum velocity magnitude used during the Scurve, trapezoidal, and velocity contouring profile modes. The velocity is specified as an unsigned 32-bit number with units of counts/sample.

The data word scaling is 1/216. The range is 0 to +1,073,741,823. The loaded velocity is not utilized until a parameter update occurs.

SET_ACC Set command acceleration

Data/direction: 2/write Encoding: 12 (hex) Axis acted on: current axis Available on: all axes Double buffered: yes

SET_ACC sets the command acceleration. When in trapezoidal pointto-point mode, the acceleration is specified as an unsigned 32-bit

number with units of counts/sample2, represented using 1/216 scaling. The range is 0 to +1,073,741,823. When in the velocity contouring mode, the acceleration is specified as a signed 32-bit number with units

of counts/sample2, represented in 1/216 format.The range is -

1,073,741,824 to +1,073,741,823. The loaded acceleration is not utilized until a parameter update occurs.

This command is used when the profile mode is set to trapezoidal point-to-point or velocity contouring.

SET_MAX_ACC Set maximum acceleration

Data/direction: 1/write Encoding: 15 (hex) Axis acted on: current axis Available on: all axes Double buffered: yes

SET_MAX_ACC sets the maximum acceleration. The acceleration is specified as an unsigned 16-bit number with units of counts/sample represented using 1/216 scaling. The range is 0 to +1,073,741,823. The

loaded max. acceleration is not utilized until a parameter update occurs.

This command is used when the profile mode is set to S-curve point to point.

SET_JERK Set command jerk

Data written: 2 words Data read: none Encoding: 13 (hex) Axis acted on: current axis Available on: all axes Double buffered: yes

SET_JERK sets the command jerk used during the S-curve profile generation mode. The jerk is specified as an unsigned 32-bit number

with units of counts/sample3. The scaling is 1/232. The range is 0 to 2,147,483,647. The loaded jerk is not utilized until a parameter update occurs.

SET_RATIO Set command gear ratio

Data/direction: 2/write Encoding: 14 (hex) Axis acted on: current axis Available on: axis #1, #2 Double buffered: yes

SET_RATIO sets the electronic gear ratio used by the trajectory profile generator. It is used when the profile mode is set to electronic gear. The gear ratio is specified as a signed 32-bit number represented using

1/216 scaling. The range is -1,073,741,824 to +1,073,741,823. The specified ratio value is defined as the number of counts of the slave axis per master axis count with a positive number indicating motion in the same direction. For example a value of +8000 hex (1/2) will result in 1/2 turn in the positive direction of the slave axis for each full turn of the master axis in the positive direction, and a value of -FFFE0000 hex (-2) will result in 2 turns in the negative direction of the slave axis for each full turn of the master axis in the positive direction. The loaded ratio is not utilized until a parameter update occurs.

STOP/CLR_PRFL Abruptly stop current axis motion

Data/direction: none Encoding: 46 (hex) Axis acted on: current axis Available on: all axes Double buffered: yes

GET_POS Get command position

Data/direction: 2/read Encoding: 4a (hex) Axis acted on: current axis Available on: all axes Double buffered: -

STOP, also known as CLR_PRFL in earlier chipset versions, stops the current axis by setting the target velocity to zero. This function will not be performed until a parameter update occurs. After the update occurs the axis trajectory generator will stop and the motion complete bit will be set. This command is useful for stopping the axis abruptly.

SMOOTH_STOP Smoot hly stop current axi s motion

Data/direction: none Encoding: 4e (hex) Axis acted on: current axis Available on: all axes Double buffered: yes

SMOOTH_STOP stops the current axis by setting the desired velocity to zero, resulting in a controlled deceleration of the axis eventually to a velocity of 0. The deceleration profile will mirror the acceleration profile for the current profile mode. For example if the SMOOTH_STOP command is given during an s-curve profile the deceleration profile may have up to three phases, depending on the # of phases during the acceleration profile, and if the SMOOTH_STOP command is given during a trapezoidal profile or a velocity mode profile the deceleration will be linear, with a value equal to the acceleration parameter.

This command does not func tion when the profile mode is set to Electronic Gear.

SYNCH_PRFL Set target position equal to the actual

position

Data/direction: none Encoding: 47 (hex) Axis acted on: current axis Available on: all axes Double buffered: yes

SYNCH_PRFL sets the trajectory profile generator target position equal to the actual axis position, clearing the following error. This command is available for all profile types. This function will not be performed until a parameter update occurs.

GET_POS returns the destination position set using the SET_POS command. It returns the double-buffered value (set directly by the host), which may or may not correspond to the active value, depending on whether the profile parameters have been updated. The returned position is a signed 32-bit number with units of counts.

GET_VEL Get command velocity

Data/direction: 2/read Encoding: 4b (hex) Axis acted on: current axis Available on: all axes Double buffered: -

GET_VEL returns the maximum velocity set using the SET_VEL command. It returns the double-buffered value (set directly by the host), which may or may not correspond to the active value, depending on whether the profile parameters have been updated. The returned

velocity is an unsigned 32-bit number in 1/216 format with units of counts/sample.

GET_ACC Get command acceleration

Data/direction: 2/read Encoding: 4c (hex) Axis acted on: current axis Available on: all axes Double buffered: -

GET_ACC returns the acceleration value set using the SET_ACC command. It returns the double-buffered value (set directly by the host), which may or may not correspond to the active value, depending on whether the profile parameters have been updated. The returned

position is either an unsigned 32-bit number in 1/216 format with units of counts/sample2, or a signed 32 bit number in 1/216 format with units of counts/sample2.

This command is used when the profile mode is set to trapezoidal point-to-point or velocity contouring.

The SYNCH_PRFL command does not set the target velocity to zero. If it is desired that the axis not move after a SYNCH_PRFL command then a STOP command, in addition to the SYNCH_PRFL command should be used.

GET_MAX_ACC Get maximum acceleration

Data/direction: 1/read Encoding: 4f (hex) Axis acted on: current axis Available on: all axes Double buffered: -

GET_MAX_ACC returns the max. acceleration value set using the SET_MAX_ACC command. It returns the double-buffered value (set directly by the host), which may or may not correspond to the active value, depending on whether the profile parameters have been

updated. The returned value is an unsigned 16-bit number in 1/2 format with units of counts/sample2.

This command is used when the profile mode is set to S-curve point to point.

GET_JERK Get command jerk

Data/direction: 2/read Encoding: 58 (hex) Axis acted on: current axis Available on: all axes Double buffered: -

GET_JERK returns the jerk value set using the SET_JERK command. It returns the double-buffered value (set directly by the host), which may or may not correspond to the active value, depending on whether the profile parameters have been updated. The returned jerk is an

unsigned 32-bit number with 1/232 scaling with units of counts/sample3.

GET_RATIO Get command gear ratio

Data/direction: 2/read Encoding: 59 (hex) Axis acted on: current axis Available on: all axes Double buffered: -

GET_TRGT_POS returns the current desired position value being generated by the trajectory profile generator. This value represents the target position for the axis at the current sample time, i.e. the position being output by the trajectory profile generator at the time of the command. This command operates for all profile modes. The value returned is a 32-bit signed number with units of counts. The range is 1,073,741,824 to 1,073,741,823. This command is useful to monitor the profile being generated by the chip set, or to verify servo performance.

GET_TRGT_VEL Return target velocity

Data/direction: 2/read Encoding: 1e (hex) Axis acted on: current axis Available on: all axes Double buffered: -

GET_TRGT_VEL returns the current desired velocity value being generated by the trajectory profile generator. This value represents the target velocity for the axis at the current sample time, i.e. the velocity being output by the trajectory profile generator at the time of the command. This command operates for all profile modes. The value returned is a 32 bit signed number with units of counts/sample,

represented in 1/216 format. The range is -1,073,741,824 to +1,073,741,823. This command is useful to monitor the profile being generated by the chip set, or to verify servo performance.

Digital Filter

SET_KP Set proportional ga in

Data/direction: 1/write Encoding: 25 (hex) Axis acted on: current axis Available on: all axes Double buffered: yes

SET_KP sets the proportional gain for the digital filter. The gain is specified as an unsigned 16-bit number. The range is 0 to 32,767. The loaded gain is not utilized until a parameter update occurs.

GET_RATIO returns the gear ratio set using the SET_RATIO command. It returns the double-buffered value (set directly by the host), which may or may not correspond to the active value, depending on whether the profile parameters have been updated. The returned ratio

is a signed 32-bit number in 1/216 format.

GET_TRGT_POS Return target position

Data/direction: 2/read Encoding: 1d (hex) Axis acted on: current axis Available on: all axes Double buffered: -

SET_KD Set derivative gain

Data/direction: 1/write Encoding: 27 (hex) Axis acted on: current axis Available on: all axes Double buffered: yes

SET_KD sets the derivative gain for the digital filter. The gain is specified as an unsigned 16-bit number. The range is 0 to 32,767. The loaded gain is not utilized until a parameter update occurs.

SET_KI Set integral gain

Data/direction: 1/write Encoding: 26 (hex) Axis acted on: current axis Available on: all axes Double buffered: yes

SET_KI sets the integral gain for the digital filter. The gain is specified as an unsigned 16-bit number. The range is 0 to 32,767. The loaded gain is not utilized until a parameter update occurs.

SET_KVFF Set velocity feed forward gain

Data/direction: 1/write Encoding: 2b (hex) Axis acted on: current axis Available on: all axes Double buffered: yes

SET_KVFF sets the velocity feed forward gain for the digital filter. The gain is specified as an unsigned 16 bit number. The range is 0 to 32,767. The loaded gain is not utilized until a parameter update occurs.

SET_MTR_BIAS Set motor output bias

Data/direction: 1/write Encoding: 0f (hex) Axis acted on: current axis Available on: all axes Double buffered: no

SET_MTR_BIAS sets the filter DC bias value, used to offset constant uni-directional forces (typically a vertical axis which is not balanced by a counter-weight). The specified motor bias value is added directly to the output of the servo filter. The motor bias is specified as a signed 16-bit number with a range of -32,767 to 32,767.

The loaded motor bias value is utilized immediately. No UPDATE command is required.

The SET_MTR_BIAS command functions during closed loop operations, as well as after a transition to open loop before a SET_MTR_CMD manual motor output command has been given. Caution should be used when selecting a motor bias value to avoid uncontrolled axis motion when transitioning to open loop mode.

SET_I_LM Set integration limit

Data/direction: 1/write Encoding: 28 (hex) Axis acted on: current axis Available on: all axes Double buffered: yes

SET_I_LM sets the integration limit for the digital filter. The integration limit is specified as an unsigned 16-bit number. The range is 0 to 32,767. The loaded integration limit is not utilized until a parameter update occurs.

SET_MTR_LMT Set motor output limit

Data/direction: 1/write Encoding: 06 (hex) Axis acted on: current axis Available on: all axes Double buffered: no

SET_MTR_LMT sets the maximum allowed motor command value output by the servo filter. The motor limit is specified as an unsigned 16-bit number with a range of 0 to 32,767. If the magnitude of the filter output value (whether positive or negative) exceeds the motor limit than the output value is maintained at the motor limit value. Once the filter output value returns below the specified limit than normal servo filter values are output.

SET_POS_ERR Set position error limit

Data/direction: 1/write Encoding: 29 (hex) Axis acted on: current axis Available on: all axes Double buffered: no

SET_POS_ERR sets the position error limit for the digital filter. The error is specified as an unsigned 16-bit number. The range is 0 to 32,767. At each servo loop the magnitude of the position error calculated by the digital filter is compared with the specified position error limit. If the actual position error exceeds the specified value, the motion error interrupt bit is set. In addition, if the axis has been set for automatic motor stop upon motion error, the axis motor output may be turned off (all power to motor is turned off). The loaded maximum position error is utilized immediately.

The value set by this command specifies the limit of the valid motion error range, but not necessarily the maximum error value. If the position error limit value is set to less than 32,767 than the actual position error may exceed the specified limit.

The loaded motor output limit is utilized immediately. No UPDATE command is required.

The SET_MTR_LMT command only functions during closed loop operations.

GET_KP Get proportional gain

Data/direction: 1/read Encoding: 50 (hex) Axis acted on: current axis Available on: all axes Double buffered: -

GET_I_LM Get integration limit

Data/direction: 1/read Encoding: 53 (hex) Axis acted on: current axis Available on: all axes Double buffered: -

GET_KP returns the proportional gain set using the SET_KP command. It returns the double-buffered value (set directly by the host), which may or may not correspond to the active value, depending on whether the filter parameters have been updated. The returned gain value is an unsigned 16-bit number.

GET_KD Get derivative gain

Data/direction: 1/read Encoding: 52 (hex) Axis acted on: current axis Available on: all axes Double buffered: -

GET_KD returns the derivative gain set using the SET_KD command. It returns the double-buffered value (set directly by the host), which may or may not correspond to the active value, depending on whether the filter parameters have been updated. The returned gain value is an unsigned 16-bit number.

GET_KI Get integral gain

Data/direction: 1/read Encoding: 51 (hex) Axis acted on: current axis Available on: all axes Double buffered: -

GET_KI returns the integral gain set using the SET_KI command. It returns the double-buffered value (set directly by the host), which may or may not correspond to the active value, depending on whether the filter parameters have been updated. The returned gain value is an unsigned 16-bit number.

GET_KVFF Get velocity feedforward gain

Data/direction: 1/read Encoding: 54 (hex) Axis acted on: current axis Available on: all axes Double buffered: -

GET_KVFF returns the proportional gain set using the SET_KVFF command. It returns the double-buffered value (set directly by the host), which may or may not correspond to the active value, depending on whether the filter parameters have been updated. The returned gain value is an unsigned 16-bit number.

GET_I_LM returns the integration limit value set using the SET_I_LM command. It returns the double-buffered value (set directly by the host), which may or may not correspond to the active value, depending on whether the filter parameters have been updated. The returned integration limit value is an unsigned 16-bit number.

GET_MTR_LMT Get motor output limit

Data/direction: 1/read Encoding: 07 (hex) Axis acted on: current axis Available on: all axes Double buffered: -

GET_MTR_LMT returns the maximum allowed motor command value output by the servo filter set using the SET_MTR_LMT command. The returned value is an unsigned 16-bit number with a range of 0 to 32,767.

GET_MTR_BIAS Get motor output bias

Data/direction: 1/read Encoding: 2d (hex) Axis acted on: current axis Available on: all axes Double buffered: -

GET_MTR_BIAS returns the filter DC bias value set using the SET_MTR_BIAS command. The returned value is a signed 16-bit number with a range of -32767 to 32,767.

GET_POS_ERR Get maximum position error

Data/direction: 1/read Encoding: 55 (hex) Axis acted on: current axis Available on: all axes Double buffered: -

GET_POS_ERR returns the maximum position error value set using the SET_POS_ERR command. The returned maximum position error value is an un signed 16-bit number.

GET_INTGR Return current integrated position error

value

Data/direction: 1/read Encoding: 2e (hex) Axis acted on: current axis Available on: all axes Double buffered: -

GET_INTGR returns the current integrated position error value maintained by the digital filter. The value returned represents the top 16 bit word of the 24-bit integration value. The value returned is a 16-bit signed number. The range is -32,768 to +32,767. This command is useful to monitor the loading on the axis, since increases or decreases in the axis load may be reflected in the value of the integration limit.

GET_ACTL_POS_ERR Return current position error

Data/direction: 1/read Encoding: 60 (hex) Axis acted on: current axis Available on: all axes Double buffered: -

GET_ACTL_POS_ERR returns the current instantaneous position error of the axis. The returned value represents the difference between the target position and the actual position (actual position minus target position), and is a signed 16-bit number. The range is -32,768 to +32,767. This command is useful to monitor and analyze the tracking error of the axis.

SET_AUTO_STOP_ON Enable automatic motor shutdown

Data/direction: none Encoding: 45 (hex) Axis acted on: current axis Available on: all axes Double buffered: no

SET_AUTO_STOP_ON enables automatic motor shutdown upon motion error. In this mode the motor will be disabled (equivalent to MTR_OFF cmd) when a motion error occurs (see SET_POS_ERR cmd). The motor output can be re-enabled using the MTR_ON cmd.

SET_AUTO_STOP_OFF Disables automatic motor shutdown

Data/direction: none Encoding: 44 (hex) Axis acted on: current axis Available on: all axes Double buffered: no

SET_AUTO_STOP_OFF disables the automatic motor shutdown upon motion error mode. In this mode the motor will not be disabled when a motion error occurs.

Parameter Update

SET_TIME_BRK Set break point mode to time based

Data/direction: none Encoding: 17 (hex) Axis acted on: current axis Available on: all axes Double buffered: no

SET_TIME_BRK sets the current breakpoint mode to time based. In this mode the value loaded into the breakpoint register (SET_BRK_PNT cmd) will represent the number of sample loops since chip set power on. After the SET_TIME_BRK command is executed, at each servo loop the break point value will be compared against the current chip set time. If the values are equal all profile and filter parameters will be loaded in to the active registers. See GET_TIME cmd for information on the chip set time. After this breakpoint condition has been satisfied, the breakpoint mode is reset i.e. no additional breakpoints will occur until a new breakpoint condition is set.

SET_POS_BRK Set break point mode to positive target

position based

Data/direction: none Encoding: 18 (hex) Axis acted on: current axis Available on: all axes Double buffered: no

SET_POS_BRK sets the current breakpoint mode to positive target position based. In this mode the value loaded into the breakpoint register (SET_BRK_PNT cmd) will represent the axis position in counts. After the SET_POS_BRK command is executed, at each servo loop the break point value will be compared against the current axis target position. If the target position has a value equal to or greater than the breakpoint register then all profile and all filter parameters will be loaded in to the active registers. After this breakpoint condition has been satisfied, the breakpoint mode is reset i.e. no additional breakpoints will occur until a new breakpoint condition is set.

SET_NEG_BRK Set break point mode to negative target

position based

Data/direction: none Encoding: 19 (hex) Axis acted on: current axis Available on: all axes Double buffered: no

SET_NEG_BRK sets the current breakpoint mode to negative target position based. In this mode the value loaded into the breakpoint register (SET_BRK_PNT cmd) will represent the axis position in counts After the SET_NEG_BRK command is executed, at each servo loop the break point value will be compared against the current axis target position. If the target position has a value equal to or less than the breakpoint register then all profile and all filter parameters will be loaded into the active registers. After this breakpoint condition has been

satisfied, the breakpoint mode is reset i.e. no additional breakpoints will occur until a new breakpoint condition is set.

in to the active registers. After this breakpoint condition has been satisfied, the breakpoint mode is reset i.e. no additional breakpoints will occur until a new breakpoint condition is set.

SET_ACTL_POS_BRK Set break point mode to positive actual

position based

Data/direction: none Encoding: 1b (hex) Axis acted on: current axis Available on: all axes Double buffered: no

SET_ACTL_POS_BRK sets the current breakpoint mode to positive actual position based. In this mode the value loaded into the breakpoint register (SET_BRK_PNT cmd) will represent the axis position in counts. After the SET_ACTL_POS_BRK command is executed, at each servo loop the break point value will be compared against the current axis actual position. If the actual position has a value equal to or greater than the breakpoint register then all profile and all filter parameters will be loaded in to the active registers. After this breakpoint condition has been satisfied, the breakpoint mode is reset i.e. no additional breakpoints will occur until a new breakpoint condition is set..

SET_ACTL_NEG_BRK Set break point mode to negative actual

position based

Data/direction: none Encoding: 1c (hex) Axis acted on: current axis Available on: all axes Double buffered: no

SET_ACTL_NEG_BRK sets the current breakpoint mode to negative actual position based. In this mode the value loaded into the breakpoint register (SET_BRK_PNT cmd) will represent the axis position in counts After the SET_ACTL_NEG_BRK command is executed, at each servo loop the break point value will be compared against the current axis actual position. If the actual position has a value equal to or less than the breakpoint register then all profile and all filter parameters will be loaded into the active registers. After this breakpoint condition has been satisfied, the breakpoint mode is reset i.e. no additional breakpoints will occur until a new breakpoint condition is set.

SET_MTN_CMPLT_BRK Set break point mode to motion

complete

Data/direction: none Encoding: 35 (hex) Axis acted on: current axis Available on: all axes Double buffered: no

No 32-bit compare value is required to be loaded when using this breakpoint mode.

It is the responsibility of the host to ensure that the motion complete bit is not set when this breakpoint is initiated.

SET_EXT_BRK Set break point mode to external

Data/direction: none Encoding: 5e (hex) Axis acted on: current axis Available on: all axes Double buffered: no

SET_EXT_BRK sets the current breakpoint mode to external. In this mode the breakpoint condition is satisfied when the home signal for the current axis becomes active (goes low). This breakpoint mode is useful for executing a profile change based on some external signal condition. Once the home signal becomes active all double-buffered profile parameters will be loaded in to the active registers. After this breakpoint condition has been satisfied, the breakpoint mode is reset i.e. no additional breakpoints will occur until a new breakpoint condition is set.

No 32-bit compare value is required to be loaded when using this breakpoint mode.

SET_BRK_OFF Set break point mode off

Data/direction: none Encoding: 6d (hex) Axis acted on: current axis Available on: all axes Double buffered: no

SET_BRK_OFF sets the breakpoint mode to "off". Any breakpoint mode that has been set previously (SET_TIME_BRK, SET_POS_BRK, SET_NEG_BRK, SET_ACTL_POS_BRK or SET_ACTL_NEG_BRK) and is still active (the breakpoint condition has not occurred), is disabled with this command. After this command has been executed no additional breakpoints will occur until a new breakpoint condition is set.

SET_MTN_CMPLT_BRK sets the current breakpoint mode to motion complete. In this mode the breakpoint condition is satisfied when the motion complete bit in the axis status word becomes active (axis motion is complete). This breakpoint mode is useful for immediately starting a new profile at the end of the current profile. Once the motion complete bit becomes active all double-buffered profile parameters will be loaded

SET_BRK_PNT Set break point comparison value

Data/direction: 2/write Encoding: 16 (hex) Axis acted on: current axis Available on: all axes Double buffered: no

SET_AUTO_UPDATE_ON Set automatic profile update on

Data/direction: none Encoding: 5c (hex) Axis acted on: current Available on: all axes Double buffered: no

SET_BRK_PNT sets the breakpoint comparison value. Its contents are interpreted based on the type of breakpoint set; time based (SET_TIME_BRK cmd) or position based (SET_POS_BRK cmd, SET_NEG_BRK cmd, SET_POS_ACTL_BRK cmd, and SET_NEG_ACTL_BRK cmd). When set to time-based the loaded value is compared with the current chip set time at each servo loop, and the value loaded is a 32-bit number with units of servo loops. When set to position-based the loaded value is compared with the current axis target or actual position at each servo loop, and the value loaded is a 32-bit number with units of counts.

UPDATE Immediately update parameters

Data/direction: none Encoding: 1a (hex) Axis acted on: current axis Available on: all axes Double buffered: no

UPDATE immediately updates all double buffered parameters.

MULTI_UPDATE Immediately update parameters for

multiple axis

Data/direction: 1/write Encoding: 5b (hex) Axis acted on: set by data word Available on: all axes Double buffered: no

MULTI_UPDATE immediately updates the profile and filter parameters for 1 or more axis simultaneously. For each updated axis, the axis behaves as if a separate UPDATE command had been given for each axis. The associated data word contains a "positive-sense" bit mask for each axis. A one (1) in the axis bit position indicates the axis will be updated. A zero (0) indicates it will not. The following table shows this bit encoding:

Bit # Axis # updated 01 12 23 34 4-15 unused, must be set to 0

SET_AUTO_UPDATE_ON sets the automatic profile update mechanism on. After this command is sent, a satisfied breakpoint condition will result in all of the double-buffered profile and filter parameters automatically being transferred to the active registers. Once set to this mode, the axis will stay in this mode until explicitly commanded out using the SET_AUTO_UPDATE_OFF command.

SET_AUTO_UPDATE_OFF Set automatic profile update off

Data/direction: none Encoding: 5d (hex) Axis acted on: current Available on: all axes Double buffered: no

SET_AUTO_UPDATE_OFF sets the automatic profile update mechanism off. After this command is sent, a satisfied breakpoint condition will not result in the double-buffered profile and filter parameters automatically being transferred to the active registers. Once set to this mode, the axis will stay in this mode until explicitly commanded out using the SET_AUTO_UPDATE_ON command.

When in this mode, the only way that profile parameters can be updated is through the UPDATE or the MULTI_UPDATE commands.

GET_BRK_PNT Get break point comparison value

Data/direction: 2/read Encoding: 57 (hex) Axis acted on: current axis Available on: all axes Double buffered: no

GET_BRK_PNT returns the breakpoint comparison value set using the SET_BRK_PNT command. The returned value is a 32-bit number with units of either servo loops or counts (depending on the current breakpoint mode).

Interrupt Processin g

SET_INTRPT_MASK Set host interrupt mask

Data/direction: 1/write Encoding: 2f (hex) Axis acted on: current axis Available on: all axes Double buffered: no

SET_INTRPT_MASK sets the interrupt mask so that interrupt events can be individually masked off. When a non-masked interrupt occurs in any axis, the interrupt signal to the host is activated (HostIntrpt pin on I/O chip). The host can choose to ignore or respond to the interrupt. Once an interrupt has been generated, no new interrupts will be generated until a RST_INTRPT command is given, after which the interrupt signal to the host will be cleared, and a new interrupt (on any axis) can be generated. The associated data word is encoded as a field of bits, with each bit representing a possible interrupting condition. A 1 value in the mask bit will cause the corresponding event to generate an interrupt, while a 0 will stop the corresponding event from interrupting the host. The bit encoding is as follows:

Bit # Event

0 Motion complete 1 position wrap-around 2 update breakpoint reached 3 position capture received 4 motion error 5 positive limit switch 6 negative limit switch 7 command error 8-15 not used, must be set to 0

GET_INTRPT Return status of the interrupting axis

Data/direction: 1/read Encoding: 30 (hex) Axis acted on: interrupting axis Available on: all axes Double buffered: -

RST_INTRPT Reset interrupting condition events

Data/direction: 1/write Encoding: 32 (hex) Axis acted on: interrupting axis Available on: all axes Double buffered: no

RST_INTRPT resets (clears) the interrupt condition bits for the axis that caused a host interrupt by masking the interrupting axis status word with the specified data word. In addition, the host interrupt signal (HostIntrpt pin on I/O chip) is de-activated.The data word is encoded as a field of bits, with each bit representing a possible interrupting condition. For each status word event bit a 1 value in the specified word will cause the status bit to remain unchanged, while a 0 will reset the corresponding event. The bit encoding is as follows:

Bit # Event 0 Motion complete 1 position wrap-around 2 breakpoint reached 3 position capture received 4 motion error 5 positive limit switch 6 negative limit switch 7 command error 8-15 not used, must be set to 0

If this command is executed when no interrupt condition is present, the command will have no effect.

GET_INTRPT_MASK Get host interrupt mask

Data/direction: 1/read Encoding: 56 (hex) Axis acted on: current axis Available on: all axes Double buffered: no

GET_INTRPT_MASK returns the interrupt mask set by the SET_INTRPT_MASK command. The returned value is a bit-encoded mask, described in the SET_INTRPT_MASK command.

GET_INTRPT returns the status of the axis that generated a host interrupt. The current axis number will not be changed after executing this command. See GET_STATUS for a definition of the returned status word. If this command is executed when no interrupt condition is present, the status of the current axis will be returned.

If this command is executed when no interrupt condition is present, the command will return the status of the current axis (same as GET_STATUS command).

Status/Mode

CLR_STATUS Clear all event bit conditions

Data/direction: none Encoding: 33 (hex) Axis acted on: current axis Available on: all axes Double buffered: no

CLR_STATUS resets (clears) all of the event bit conditions for the axis (bits 0-7 of the status word). The host interrupt line is not affected by this command. This command is useful for clearing all event bits during

initialization, or during on-line usage if the interrupt line and associated commands are not being used. For a detailed description of the status word event bits, see the GET_STATUS command.

This command does not af fect the status of the host interrupt line, only the status event-bits themselves. To reset the host interrupt line, a RST_INTRPT command must be sent.

RST_STATUS Reset specific event bit conditions

Data/direction: 1/write Encoding: 34 (hex) Axis acted on: current axis Available on: all axes Double buffered: no

RST_STATUS resets (clears) the condition event bits for the current axis, using a data word mask. The data word is encoded as a field of bits, with each bit representing a possible condition event. For each status word event bit a 1 value in the specified data word will cause the status bit to remain unchanged, while a 0 will reset the corresponding event. The bit encoding is as follows:

GET_STATUS Get axis status word

Data/direction: 1/read Encoding: 31 (hex) Axis acted on: current axis Available on: all axes Double buffered: -

10 In-motion bit (1 indicates axis is in motion) 11 reserved (may be 0 or 1) 12,13 current axis # (13 bit = high bit, 12 bit = low bit) 14,15 reserved (may be 0 or 1)

Bits 0-7 are set by the chipset, and must be reset by the host (using CLR_STATUS, RST_STATUS, or RST_INTRPT commands). Bits 8, 9, 10, 12, and 13 are continuously maintained by the c hipset and are not set or reset by the host.

GET_MODE Get axis mode word

Data/direction: 1/read Encoding: 48 (hex) Axis acted on: current axis Available on: all axes Double buffered: -

GET_MODE returns the mode word for the axis.The bit encoding of the returned word is as follows:

Bit # Event 0-6 Contains no host-useable information. 7 Stop on motion error mode flag. 1 indicates auto

stop is on. 8 Internal use only. Contains no host-useable data 9 Contains no host-useable information 10 Auto update flag. 1 indicates auto update is

disabled. 11,12 Trajectory profile mode, encoded as follows:

Bit 12 Bit 11 Profile Mode

0 0 trapezoidal

0 1 velocity contouring

10s-curve

1 1 electronic gear 13-15 Phase # (S-curve profile only). 3-bit word encodes

phase #. Bit 15 is MSB, bit 13 is LSB.

Encoder

GET_STATUS returns the status of the current axis.The bit encoding of the returned word is as follows:

Bit # Event 0 motion complete (1 indicates complete) 1 position wrap-around (1 indicates wrap) 2 update breakpoint reached (1 indicates reached) 3 position capture received (1 indicates capture has

occurred) 4 motion error (1 indicates motion error) 5 positive limit switch (1 indicates limit switch trip) 6 negative limit switch (1 indicates limit switch trip) 7 command error (1 indicates command error) 8 motor on/off status (1 indicates on) 9 axis on/off status (1 indicates on)

SET_CNTS Set # of counts per motor revolution

Data/direction: 1/write Encoding: 68 (hex) Axis acted on: current axis Available on: all axes Double buffered: no

SET_CNTS sets the number of counts per motor revolution for the current axis. The actual value that should be sent to the chipset is 1/2 the desired number of counts per motor revolution. For example if a 12 bit resolver is used (total of 4096 output states) then the value 2048 should be specified. The associated data word is an unsigned 16 bit number, with an allowed range of 256 to 32,767.

This command can only be used with the -P version parts.

SET_CAPT_INDEX Set position capture trigger source to

the index signal

Data/direction: none Encoding: 64 (hex) Axis acted on: current axis Available on: all axes Double buffered: no

SET_CAPT_INDEX sets the high-speed position register trigger source to the index signal. When the index is used as the trigger source, it is gated by the A and B quadrature signals (see theory of operations for details).

Motor

SET_OUTPUT_PWM Set motor output mode to PWM

Data/direction: none Encoding: 3c (hex) Axis acted on: global (all axes) Available on: all axes Double buffered: no

SET_OUTPUT_PWM sets the motor output mode to PWM. PWM mode outputs the motor output value on 2 output signals (sign and magnitude) for each enabled axis. This command affects the output mode for all axes.

SET_CAPT_HOME Set position capture trigger source to

the home signal

Data/direction: none Encoding: 65 (hex) Axis acted on: current axis Available on: all axes Double buffered: no

SET_CAPT_HOME sets the high-speed position register trigger source to the home signal.

GET_CAPT Return high speed capture register

Data/direction: 2/read Encoding: 36 (hex) Axis acted on: current axis Available on: all axes Double buffered: -

GET_CAPT returns the current value of the high-speed position capture register, as well as resets the capture hardware so that subsequent positions may be captured. The value returned is a 32 bit signed number with units of counts.

GET_CNTS Return # of counts per motor revolution

Data/direction: 1/read Encoding: 6f (hex) Axis acted on: current axis Available on: all axes Double buffered: -

GET_CNTS returns the # of counts per motor revolution value set using the SET_CNTS command. The returned value is a 16 bit unsigned number. This command is only valid with the -P version parts.

SET_OUTPUT_DAC16 Set motor output mode to 16-bit DAC

Data/direction: none Encoding: 3b (hex) Axis acted on: global (all axes) Available on: all axes Double buffered: no

SET_OUTPUT_DAC16 sets the motor output mode to 16-bit DAC. This motor output mode uses a 16-bit data bus, along with various control signals to load a DAC value for each enabled axis. This command affects the output mode for all axes.

MTR_ON Enable servo motor output

Data/direction: none Encoding: 43 (hex) Axis acted on: current axis Available on: all axes Double buffered: no

MTR_ON enables closed loop servo control. When motor output is enabled, motor output values generated by the digital filter are output to the selected output hardware circuitry (PWM, DAC12 or DAC16).

MTR_OFF Disable servo motor output

Data/direction: none Encoding: 42 (hex) Axis acted on: current axis Available on: all axes Double buffered: no

MTR_OFF disables closed loop servo operations. After this command is executed the motor output is taken from the motor command register, set using the SET_MTR_CMD command. This register is loaded with a value of 0 at the moment the motor is disabled. This command can be used for emergency shutdowns, for calibrating the motor amplifier, or for running an axis in open loop mode.

SET_MTR_CMD Write direct value to motor output

Data/direction: 1/write Encoding: 62 (hex) Axis acted on: current axis Available on: all axes Double buffered: no

SET_MTR_CMD loads the motor command register with the specified value. This register replaces the motor command value from the servo filter when the motor is shut off (MTR_OFF command). The specified motor command is a 16-bit signed number with range -32,767 to +32,767. Regardless of the motor output mode (PWM, DAC12 or DAC16), a value of -32,767 represents the largest negative direction motor command, a value of 0 represents no motor (0) output command, and a value of 32,767 represents the largest positive motor command.

Miscellaneous

AXIS_ON Enable current axis

Data/direction: none Encoding: 41 (hex) Axis acted on: current axis Available on: all axes Double buffered: no

AXIS_ON enables the current axis. Axes that are on are serviced normally. Axes that are off are not serviced, and will not support any axis features. Axes can be enabled or disabled at any time, although care should be taken not to disable an axis such that unsafe motion occurs.

For this command to work properly, the chipset must be in open loop mode (MTR_OFF cmd or after a motion error with automatic motor stop enabled)

GET_MTR_CMD Read current motor output value

Data/direction: 1/read Encoding: 3a (hex) Axis acted on: current axis Available on: all axes Double buffered: -

GET_MTR_CMD returns the current motor output command. When the chipset is in closed loop mode this command returns the output of the servo filter. When the chipset is in open loop mode this command returns the contents of the manual output register, set using the SET_MTR_CMD command.

GET_OUTPUT_MODE Get current motor output mode

Data/direction: 1/read Encoding: 6e (hex) Axis acted on: global (all axes) Available on: all axes Double buffered: -

GET_OUTPUT_MODE returns the current motor output mode set using the SET_OUTPUT_PWM, SET_OUTPUT_DAC12, and SET_OUTPUT_DAC16 commands. The returned 16 bit word contains the motor output mode. The encoding is as follows:

Returned Word Value Output Mode

0PWM 1DAC12 2DAC16

AXIS_OFF Disable current axis

Data/direction: none Encoding: 40 (hex) Axis acted on: current axis Available on: all axes Double buffered: no

AXIS_OFF disables the current axis. Axis that are on are serviced normally. Axis that are off are not serviced, and will not support any axis features. Axes can be enabled or disabled at any time, although care should be taken not to disable an axis such that unsafe motion occurs.

SET_ACTL_POS Set actual axis position

Data/direction: 2/write Encoding: 4d (hex) Axis acted on: current axis Available on: all axes Double buffered: no

SET_ACTL_POS sets the current actual position to the specified value. In addition, it sets the current target position equal to the specified actual position minus the current actual position error. In this way the current actual position error is maintained, allowing the SET_ACTL_POS command to be used while the axis is moving without causing the servo axis to jump. The desired actual axis position is specified as a signed 32 bit number with an allowed range of 1,073,741,824 to 1,073,741,823.

The loaded position is utilized immediately. No UPDATE is required for the command to take effect.

GET_ACTL_POS Return actual a xis position

Data/direction: 2/read Encoding: 37 (hex) Axis acted on: current axis Available on: all axes Double buffered: -

GET_ACTL_POS returns the current actual position of the current axis. The value read is up to date to within a servo sample time.The value returned is a 32 bit signed number with units of counts.

Bit # Description 0 Axis 1 positive limit switch (1 = high) 1 Axis 1 negative limit switch (1 = high) 2 Axis 2 positive limit switch (1 = high) 3 Axis 2 negative limit switch (1 = high) 4 Axis 3 positive limit switch (1 = high) 5 Axis 3 negative limit switch (1 = high) 6 Axis 4 positive limit switch (1 = high) 7 Axis 4 negative limit switch (1 = high) 8-15 not used (set to 0)

SET_LMT_SENSE Set limit switch bit sense

Data/direction: 1/write Encoding: 66 (hex) Axis acted on: global (all axes) Available on: all axes Double buffered: -

SET_LMT_SENSE sets the interpretation of the limit switch input bits. This command provides added flexibility in interfacing to various switch/sensor components. The signal level interpretation for the positive and negative switch inputs are bit-programmable. A 0 in the corresponding bit of the sense word indicates that the input will be active high. A 1 in the sense word indicates that the input will be active low. The sense word is encoded as follows:

Bit # Description 0 Axis 1 positive limit switch (0 = active high) 1 Axis 1 negative limit switch (0 = active high) 2 Axis 2 positive limit switch (0 = active high) 3 Axis 2 negative limit switch (0 = active high) 4 Axis 3 positive limit switch (0 = active high) 5 Axis 3 negative limit switch (0 = active high) 6 Axis 4 positive limit switch (0 = active high) 7 Axis 4 negative limit switch (0 = active high) 8-15 not used (must set to 0)

The above bits are encoded as shown for the MC1401A. For the MC1201A Axis 3 & 4 are not used, and for the MC1101A Axis 2,3 & 4 are not used.

GET_LMT_SWTCH Get state of over-travel limit switches

Data/direction: 1/read Encoding: 67 (hex) Axis acted on: global (all axes) Available on: all axes Double buffered: -

The above bits are encoded as shown for the MC1401A. For the MC1201A Axis 3 & 4 will always be set to 0, and for the MC1101A Axis 2,3 & 4 will always be set to 0.

The values returned by this command are not affected by the SET_LMT_SENSE command.

LMTS_ON Set limit switch sensing on

Data/direction: none Encoding: 70 (hex) Axis acted on: global (all axes) Available on: all axes Double buffered: -

LMTS_ON turns the limit switch sensing mechanism on. This command is primarily intended for compatibility with the MC1400 chipset, although it can also be used to re-enable limit switch sensing whenever it has been disabled using the LMTS_OFF command.

LMTS_OFF Set limit switch sensing off

Data/direction: none Encoding: 71 (hex) Axis acted on: global (all axes) Available on: all axes Double buffered: -

LMTS_OFF turns the limit switch sensing mechanism off. This command is primarily intended for compatibility with the MC1400 chipset, although it can also be used whenever it is desired that limit switch sensing not be active.

This command only disables the automatic setting of the negative and positive limit switch bits in the status word. It does not affect the status of these bits if they have already been set, nor does it affect the GET_LMT_SWTCH command.

GET_LMT_SWTCH returns the value of the limit switch input signals for all valid axis. The returned word is encoded as follows:

GET_HOME Get state of home signal inputs

Data/direction: 1/read Encoding: 05 (hex) Axis acted on: global (all axes) Available on: all axes Double buffered: -

RESET Reset chip set

Data/direction: none Encoding: 39 (hex) Axis acted on: global (all axes) Available on: all axes Double buffered: No

GET_HOME returns the value of the home signal inputs for all valid axes. The returned word is encoded as follows:

Bit # Description 0 Axis 1 home signal (1 = high) 0 Axis 2 home signal (1 = high) 0 Axis 3 home signal (1 = high) 0 Axis 4 home signal (1 = high) 4-15 not used (set to 0)

The above bits are encoded as shown for the MC1401A. For the MC1201A Axis 3 & 4 will always be set to 0, and for the MC1101A Axis 2,3 & 4 will always be set to 0.

SET_SMPL_TIME Set servo loop sample time

Data/direction: 1/write Encoding: 38 (hex) Axis acted on: global (all axes) Available on: all axes Double buffered: No

SET_SMPL_TIME sets the servo sampling time which is the amount of time between servo updates. All axes operate at the same sample rate, and therefore are all affected by this command. The written value consists of the sample time expressed in units of 100 micro-seconds. For example a written value of 4 sets the loop time to 400 uSec. The allowed range is 1 to 32,767, however see theory of operations section for guidelines on the minimum values that can be used.

GET_SMPL_TIME Get servo loop sample time

Data/direction: 1/read Encoding: 61 (hex) Axis acted on: global (all axes) Available on: all axes Double buffered: No

RESET resets the entire chip set. This command performs the same sequence as a hardware reset. At the end of this operation the chip set will be in the default or powerup condition, defined as follows:

Condition Initial Value all actual axis positions 0 all capture registers 0 all event conditions cleared host interrupt (HostIntrpt) signal not active all interrupt masks 0 all profile modes trapezoidal all filter modes PID all profile parameter values 0 all filter gains 0 all integration limits 32,767 all max. position error values 32,767 all motor biases 0 all motor limits 32,767 all brkpnt comparison values 0 all auto updates enabled (on) all axes enabled (on) all capture input modes index all counts per motor rev. 0 operational Mode Closed loop (MTR_ON) all auto stop modes enabled (on) limit switch sensing enabled (on) limit switch sense 0 (all active high) output mode PWM all motor output values 0 current axis number 1 sample time 4 - MC1401A

2 - MC1201A 1 - MC1101A

GET_SMPL_TIME returns the sample time set using the command SET_SMPL_TIME. The returned value is a 16 bit unsigned number with units of 100 uSecs.

GET_VRSN Return chipset software information

Data/direction: 1read Encoding: 6c (hex) Axis acted on: global (all axes) Available on: all axes Double buffered: -

GET_TIME Return current chip set time.

Data/direction: 2/read Encoding: 3e (hex) Axis acted on: global (all axes) Available on: all axes Double buffered: -

GET_VRSN returns various information on the chipset part number and software version. The encoding is as follows:

Bit # Interpretation 0-2 minor software version 3-4 major software version. Major software versions 2

and above indicate 'A' versions parts 5-7 "dash" version # (no dash = 0, -P = 1 8-10 part number code 0 = 00 (MC1400-series), 1 = 01

(MC1401-series), 2 = 31 (MC1231-series) , 3 = 41

(MC1241-series), 4 = 51 (MC1451-series) 11-13 # axes supported (0 = 1) 14-15 generation # (1)

For example, the returned version code for the MC1401 (version 1.0 software) is 5908 (hex), the returned version code for the MC1201-P (version 1.0 software) is 4928, and the returned version code for the MC1231 (version 1.3 software) is 4a0b

GET_TIME returns the current system time, expressed as the number of servo loops since chip set power on.The chip set clock starts at 0 after a power on or reset and will count indefinitely, wrapping from a value of 4,294,967,295 to 0. The returned value is a 32 bit number with units of sample times.

NOTES

Application Notes

Interfacing MC1401A to ISA bus.

A complete, ready-to-use ISA (PC/AT) bus interface circuit has been provided to illustrate MC1401A host interfacing, as well as to make it easier for the customer to build an MC1401A development system.

The interface between the PMD MC1401A chip set and the ISA (PCAT) Bus is shown on the following page.

Comments on Schematic

This interface uses a 22V10 PAL and a 74LS245 to buffer the data lines.This interface assumes a base address is assigned in the address space of A9-A0. 300-400 hex These addresses are generally available for prototyping and other system-specific uses without interfering with system assignments. This interface occupies 16 addresses from XX0 to XXF hex though it does not use all the addresses. Two select lines are provided allowing the base address to be set to 340,350,370 and 390 hex for the select lines S1,S0 equal to 0,1,2,and 3 respectively.The address assignments used are as follows, where BADR is the base address, 340 hex for example:

Address use 340h read-write data 342h write command 344h read status (HostRdy) [D7 only] 348h write reset [Data= don't care]

The base address (BADR) is decoded in ADRDEC. It is nanded with SA2:SA3, BADR+0, (B+0) to form -HSEL to select the I/O chip. B+0 nanded with IOR* forms -HRD, host read, directly. The 22V10 tail-bites the write pulse since the setup time is greater than necessary on the bus some of the bus duration is used to generate data hold time at the I/O chip. -HWR, host write is set the first clock after B+0 and IOW* is recognized. The next clock sets TOG and clears -HWR. TOG remains set holding -HWR clear until IOW* is unasserted on the bus indicating the end of the bus cycle. B+4 and IOR* out enables HRDY to SD7 so the status of HRDY may be tested. SD7 is used since the sign bit of a byte may be easily tested. The rest of the data bits are left floating and should be ignored. B+8 and IOW* generate a reset pulse which will init the interface by clearing the two write registers and outputs a reset pulse, -RS, for the CP chip. The reset instruction is OR'd with RESET on the bus to initialize the PMD chip set when the PC is reset.

Parallel-Word Device Interface

The following schematic shows a typical interface circuit between the MC1401A and a parallel-word position input device.

Using the same basic circuit, any number of parallel-word devices such as a resolver (after R/D conversion), an absolute encoder, or a laser interferometer could be used).

Comments on Schematic

The parallel word device interface schematic is illustrated using a 74HCT374. The CP does not distinguish between internal fetches from program memory and external reads so, as can be seen from the timing diagram (in the Electrical Characteristics section of the manual), multiple reads will take place on the external bus. The CP will ignore the external timing during instruction fetches. As a result the external device can put data on the bus during the instruction fetches but autoincrement addressing of words or bytes can not be used. The CP selects the device with PosSlct. The address of the selected axis, DACAddr[0:1] is also set at the beginning of the transfer and maintained through the transfer. The address bits are decoded by the 74HCT138 and enabled by PosSlct and I/OCntrl0 (the CP read signal).

PWM Motor Interface

The following schematic shows a typical interface circuit between the MC1401A used in PWM output mode.

The LMD18200 H-bridge driver is used. To simplify the schematic, a diode bridge has been shown for 1 axis only. The diode bridge for the other 3 axis is identical.

16-bit Parallel DAC Interface

The Interface between the MC1401A chip set and one or more 16 bit DACs is shown in the following figure.

Comments on Schematic

The 16 Data bits and 2 address bits from the CP chip are latched in the two 74FCT841 latches when the CP writes to address F hex, in the address bits A0:A3. Three 74C373 latches could also be used. If this is a write to the DAC, DAC SLCT will be asserted during this CP bus cycle. The assertion of DACSLCT will be latched by the fed-back and-or gate and the next clock will set the DACWR flop. The second clock will set the second shift flop which will clear the DACL latch. Since this latch has been cleared the third clock will clear DACWR providing a two clock DACWR level. The fourth clock will clear the second shift flop returning the system to its original state waiting for the next DACSLCT. The DACWR assertion will enable the decoder causing the DAC selected by the address bits stored in the transparent latch. The timing described will produce a two clock write pulse to the DACs. This will be about 320 nSec using I/OClk.

16-Bit Serial DAC Interface

The following schematic shows an interface circuit between the MC1401A and a dual 16-bit serial DAC

Comments on Schematic

The 16 data bits and the two address bits from the CP chip are latched in the two 74HC821 latches when the CP writes to address F hex, in the address bits A0-A3. Three 74HC373 latches could also be used. If this is a write to the DAC, DACSlct will b e asserted durin g this CPU cycle. The assertion of DACSlct will be latched by the fed-back and-or gate, and the next clock will set the DACWR latch. The second clock will set the second shift flop which will clear the DACL latch. Since this latch has been cleared the third clock will clear DACWR providing a two clock DACWR level. The fourth clock will clear the second shift flop returning the system to its original state waiting for the next DACSlct.

When the DACWR flop is set the 16 bit shift register implemented by the 2 74FCT299's are parallel loaded with the 16 bits of data for the DAC. The 4 bit counter, 74FCT161, is also parallel loaded to 0, and the counter is enabled by clearing the ENP flop, which is contained in half of the 74HCT109. The counter will not start counting nor the shift register start shifting until the clock after the DACWR flop clears since the load overrides the count enable. When the DACWR flop is cleared the shift register will start shifting and the counter will count the shifts. After 15 shifts CNT15 from the counter will go high and the next clock will set the DACLAT flop and clear ENP flop. This will stop the shift after 16 shifts and assert L1 through L4 depending on the address stored in the latch. The 16th clock also was counted causing the counter to roll over to 0 and CNT15 to go low. The next clock will therefore clear the DACLAT flop causing the DAC latch signal L1 through L4 to terminate and the 16 bits of data to be latched in the addressed DAC. The control logic is now back in its original state waiting for the next write to the DACs by the CP.

NOTES

Incremental Encoder

Index B A

Home

1/a



1/a 1/a

I/O Chip

Internal Bl o ck Diagram

Parallel Input

(-P chipset only)

8 data

2 Control

PWM sign,

mag

1/phase 2

DAC, PWM signal generator (1-4

Motor Output

DAC address

CP Chip

DAC

Quadrature

decoder

counter (1-4)

Position

capture register

Host I/O controller

Available Configurations:

Operating Modes: Position Range:

Velocity Range: Acceleration Range:

Jerk Range: Trajectory Profile Generator Mode s:

Electronic Gear Ratio Range: Filter Modes: Filter Parameter Resolution: Motor Output Formats:

Max. Enco der Rate: Parallel Encoder Word Size: Max. Servo Loop Rate: # of Limit Switches Per Axis: # Of Position Capture Triggers: Capture Trigger Latency: # of Host Commands:

Position

Host command

185

host interruptDataControl

Digital Servo filtering (1-4)

System Registers (1-4)

1/a

PosLimit

Trajectory

profile generator

1/a

NegLimit

Technical Specifications

4 axes with incremental quadrat ure encoder input (MC 1401A) 2 axes with incremental quadrat ure encoder input (MC 1201A) 1 axes with incremental quadrat ure encoder input (MC 1101A) 4 axes with parallel word encoder input (MC1401A-P) 2 axes with parallel word encoder input (MC1201A-P) 1 axes with parallel word encoder input (MC1101A-P) Closed loop (motor command is driven from output of servo filter) Open loop (motor command is driven from user-programmed register)

-1,073,741,824 to 1,073,741,8 23 counts

-16,384 to 16,3 83 cou nts/sample with a resolution of 1/65,536 counts/sa m ple S-curve profile: -1/2 t o 1/2 counts/sample^2 with a resolution of 1/65,536 counts/sample^2 All other profiles: -16,384 to 16,383 counts/sample^2 with a resolution of 1/65, 536 counts/sample^2

-1/2 to 1/2 counts/sample^3, with a resolution of 1/4,294,967,29 6 cou nts/sample^3 S-curve (host commands final position, maximum velocity, maximum acceleration, and jerk) Trapezoidal (host comman ds final position, maximum velocity, and acceleration) Velocity contouring (host commands maximum velocity, acceleration) Electronic Gear (Encoder position of one axis is used as position command for another axis). 32768:1 to 1:32768 (negative and positive direction) PID+Vff (Proportional, Integral, Derivative, velocity feedforward, DC bias) 16 bits PWM (10 bits resolution @ 24.5 Khz) DAC (16 bits) Incremental: 1.0 Megaco unt s/sec, Parallel-word: 80.0 Mcounts/sec. 16 bits (read in 2 byte reads, -P ver sion on ly) 100 uSec per enabled axis 2 (one for each direction of travel) 2 (index, home signal) 160 nSec 94

Ordering

Chipset

P/N: MC1 01A -

4 - 4 axis 2 - 2 axis 1 - 1 axis

No dash - Incremental encoder P - parallel encoder

Information

Custom versions of

chipset availabl e

upon request. Call

Performance Motion Dev ices, In c. 12 Waltham St. Le xington, M A 02421 te l: 781. 674.98 60 fax: 781.674.9 861

Chipset Developer's Kit

p/n: DK1401A - *

*Supports MC1401A, MC1201A, MC1101A,

No dash - Incremental encoder P - parallel encoder

www.pmdcorp.com

Datasheet MC1401A, MC1401A-P, MC1101A, MC1101A-P, MC1201A Datasheet (PMD)

Specifications and Main Features

Frequently Asked Questions

User Manual

Table of Contents

Product Family Overview

Introduction

Family Summary

Electrical Characteristics

Overview

Absolute Maximum Ratings

Operating Ratings

DC Electrical Characteristics

AC Electrical Characteristics

I/O Timing Diagrams

Pinouts

Pin Descriptions

Theory of Operations

Trajectory Profile Generation

Trajectory Control

Digital Servo Filtering

Parameter Loading & Updating

Travel Limit Swit ches

Motion Error Detection and Recovery

Axis Timing

Host Communications

Axis Status

Host Interrupts

Encoder Position Feedback

Motor Outputs

Command Summary

Command Reference

Axis Control

Profile Generation

Digital Filter

Parameter Update

Interrupt Processin g

Status/Mode

Encoder

Motor

Miscellaneous

Application Notes