Galil DMC-3425 User Manual
DMC-3425
Manual Rev. 1.1b
USER MANUAL
By Galil Motion Control, Inc.
Galil Motion Control, Inc.
3750 Atherton Road
Rocklin, California 95765
Phone: (916) 626-0101
Fax: (916) 626-0102
Internet Address: support@galilmc.com
URL: www.galilmc.com
Rev 6/06
Contents
Contents i
Chapter 1 Overview 1
Introduction ...............................................................................................................................1
Overview of Motor Types..........................................................................................................2
DMC-3425 Functional Elements ............................................................................................... 4
Standard Servo Motors with +/- 10 Volt Command Signal.........................................2
Stepper Motor with Step and Direction Signals ..........................................................2
Brushless Servo Motor with Sinusoidal Commutation................................................2
Microcomputer Section ...............................................................................................4
Motor Interface............................................................................................................ 4
Communication ........................................................................................................... 4
General I/O..................................................................................................................5
System Elements ......................................................................................................... 5
Motor...........................................................................................................................5
Amplifier (Driver) ....................................................................................................... 5
Encoder........................................................................................................................6
Watch Dog Timer........................................................................................................6
Chapter 2 Getting Started 7
The DMC-3425 Motion Controller............................................................................................ 7
Elements You Need ................................................................................................................... 8
Installing the DMC-3425 Controller.......................................................................................... 8
Step 1. Determine Overall Motor Configuration........................................................ 9
Step 2. Configuring Jumpers on the DMC-3425......................................................... 9
Step 3. Connecting AC or DC power and the Serial Cable to the DMC-3425 .......... 11
Step 4. Installing the Communications Software.......................................................12
Step 5. Establishing Communication between the DMC-3425 and the host PC ....... 12
Step 6. Set-up axis for sinusoidal commutation (optional)....................................... 17
Step 7. Make connections to amplifier and encoder..................................................17
Step 8a. Connect Standard Servo Motor...................................................................19
Step 8b. Connect brushless motor for sinusoidal commutation................................ 23
Step 8c. Connect Step Motors ................................................................................... 26
Step 9. Tune the Servo System.................................................................................. 27
Step 10. Configure the Distributed Control System.................................................. 28
Design Examples .....................................................................................................................32
Example 1 - System Set-up ....................................................................................... 32
Example 2 - Profiled Move .......................................................................................32
Example 3 - Position Interrogation............................................................................ 32
Example 4 - Absolute Position .................................................................................. 32
DMC-3425 Contents • i
Example 5 - Velocity Control (Jogging) ...................................................................33
Example 6 - Operation Under Torque Limit .............................................................33
Example 7 - Interrogation.......................................................................................... 33
Example 8 - Operation in the Buffer Mode............................................................... 33
Example 9 - Motion Programs...................................................................................34
Example 10 - Motion Programs with Loops..............................................................34
Example 11- Motion Programs with Trippoints........................................................ 34
Example 12 - Control Variables................................................................................ 35
Example 13 - Control Variables and Offset ..............................................................35
Chapter 3 Connecting Hardware 37
Overview .................................................................................................................................37
Using Inputs............................................................................................................................. 37
Limit Switch Input.....................................................................................................37
Home Switch Input.................................................................................................... 38
Abort Input ................................................................................................................ 38
Uncommitted Digital Inputs ...................................................................................... 39
Amplifier Interface .................................................................................................................. 39
TTL Inputs...............................................................................................................................40
Analog Inputs ..........................................................................................................................40
TTL Outputs ............................................................................................................................ 41
Chapter 4 Communication 43
Introduction .............................................................................................................................43
RS232 Port............................................................................................................................... 43
RS232 - Port 1 DATATERM ................................................................................ 43
RS-232 Configuration ...............................................................................................43
Ethernet Configuration ............................................................................................................44
Communication Protocols ......................................................................................... 44
Addressing................................................................................................................. 44
Ethernet Handles .......................................................................................................45
Global vs. Local Operation........................................................................................45
Operation of Distributed Control...............................................................................47
Accessing the I/O of the Slaves................................................................................. 47
Handling Communication Errors...............................................................................48
Multicasting............................................................................................................... 48
Unsolicited Message Handling.................................................................................. 49
IOC-7007 Support ..................................................................................................... 49
Modbus Support ........................................................................................................ 50
Other Communication Options..................................................................................51
Data Record ............................................................................................................................. 52
Data Record Map....................................................................................................... 52
Explanation of Status Information and Axis Switch Information..............................55
Notes Regarding Velocity and Torque Information .................................................. 56
QZ Command............................................................................................................56
Using Third Party Software....................................................................................... 57
Chapter 5 Command Basics 59
Introduction .............................................................................................................................59
Command Syntax - ASCII....................................................................................................... 59
Coordinated Motion with more than 1 axis............................................................... 60
Command Syntax - Binary ......................................................................................................60
Binary Command Format.......................................................................................... 61
Binary command table...............................................................................................62
ii • Contents DMC-3425
Controller Response to DATA ................................................................................................63
Interrogating the Controller ..................................................................................................... 64
Interrogation Commands...........................................................................................64
Summary of Interrogation Commands ...................................................................... 64
Interrogating Current Commanded Values................................................................ 64
Operands....................................................................................................................64
Command Summary.................................................................................................. 65
Chapter 6 Programming Motion 67
Overview .................................................................................................................................67
Global vs. Local Operation........................................................................................67
Independent Axis Positioning.................................................................................................. 69
Command Summary - Independent Axis ..................................................................70
Operand Summary - Independent Axis ..................................................................... 70
Examples ................................................................................................................... 70
Independent Jogging................................................................................................................72
Command Summary - Jogging.................................................................................. 72
Operand Summary - Independent Axis ..................................................................... 72
Examples ................................................................................................................... 72
Linear Interpolation Mode (Local Mode)................................................................................73
Specifying Linear Segments...................................................................................... 73
Additional Commands............................................................................................... 74
Command Summary - Linear Interpolation...............................................................75
Operand Summary - Linear Interpolation..................................................................75
Example..................................................................................................................... 76
Example - Linear Move............................................................................................. 76
Example - Multiple Moves........................................................................................77
Vector Mode: Linear and Circular Interpolation (Local Mode) ..............................................78
Specifying Vector Segments .....................................................................................78
Additional commands................................................................................................ 79
Command Summary - Coordinated Motion Sequence..............................................80
Operand Summary - Coordinated Motion Sequence................................................. 80
Electronic Gearing (Local Mode)............................................................................................ 82
Command Summary - Electronic Gearing ................................................................82
Electronic Cam (Local Mode) .................................................................................................83
Contour Mode (Local Mode)................................................................................................... 89
Specifying Contour Segments ................................................................................... 89
Additional Commands............................................................................................... 91
Command Summary - Contour Mode ....................................................................... 91
Operand Summary - Contour Mode .......................................................................... 91
Virtual Axis (Local Mode) ......................................................................................................94
Ecam Master Example............................................................................................... 95
Sinusoidal Motion Example ...................................................................................... 95
Stepper Motor Operation ......................................................................................................... 95
Specifying Stepper Motor Operation......................................................................... 95
Stepper Motor Smoothing ......................................................................................... 96
Monitoring Generated Pulses vs. Commanded Pulses ..............................................96
Motion Complete Trippoint....................................................................................... 97
Using an Encoder with Stepper Motors..................................................................... 97
Command Summary - Stepper Motor Operation.......................................................97
Operand Summary - Stepper Motor Operation..........................................................97
Dual Loop (Auxiliary Encoder)...............................................................................................98
Using the CE Command............................................................................................ 98
Additional Commands for the Auxiliary Encoder..................................................... 98
Backlash Compensation ............................................................................................98
DMC-3425 Contents• iii
Example..................................................................................................................... 99
Motion Smoothing................................................................................................................. 100
Using the IT and VT Commands:............................................................................100
Example................................................................................................................... 100
Homing .................................................................................................................................. 101
Example................................................................................................................... 102
Command Summary - Homing Operation...............................................................104
Operand Summary - Homing Operation.................................................................. 104
High Speed Position Capture (Latch) .................................................................................... 104
Example................................................................................................................... 105
Chapter 7 Application Programming 107
Overview ...............................................................................................................................107
Global vs. Local Programming................................................................................107
Entering Programs .................................................................................................................108
Edit Mode Commands............................................................................................. 108
Example:.................................................................................................................. 109
Program Format..................................................................................................................... 109
Using Labels in Programs .......................................................................................109
Special Labels..........................................................................................................110
Commenting Programs............................................................................................ 110
Executing Programs - Multitasking ....................................................................................... 111
Debugging Programs .............................................................................................................112
Trace Command ...................................................................................................... 113
Error Code Command..............................................................................................113
Stop Code Command...............................................................................................113
RAM Memory Interrogation Commands ................................................................ 113
Operands..................................................................................................................114
Breakpoints and single stepping.............................................................................. 114
EEPROM Memory Interrogation Operands............................................................ 114
Program Flow Commands ..................................................................................................... 115
Event Triggers & Trippoints....................................................................................115
Conditional Jumps...................................................................................................119
If, Else, and Endif.................................................................................................... 121
Subroutines.............................................................................................................. 123
Stack Manipulation..................................................................................................123
Auto-Start and Auto Error Routine .........................................................................123
Automatic Subroutines for Monitoring Conditions.................................................124
Mathematical and Functional Expressions ............................................................................ 127
Mathematical Operators ..........................................................................................127
Bit-Wise Operators.................................................................................................. 128
Functions ................................................................................................................. 129
Variables................................................................................................................................129
Programmable Variables ......................................................................................... 130
Operands................................................................................................................................131
Special Operands.....................................................................................................131
Examples ................................................................................................................. 132
Arrays ....................................................................................................................................132
Defining Arrays.......................................................................................................132
Assignment of Array Entries................................................................................... 132
Uploading and Downloading Arrays to On Board Memory....................................133
Automatic Data Capture into Arrays.......................................................................133
Deallocating Array Space........................................................................................ 135
Outputting Numbers and Strings ........................................................................................... 135
Sending Messages ...................................................................................................135
iv • Contents DMC-3425
Displaying Variables and Arrays............................................................................. 137
Interrogation Commands.........................................................................................137
Formatting Variables and Array Elements .............................................................. 139
Converting to User Units......................................................................................... 140
Hardware I/O ......................................................................................................................... 140
Digital Outputs ........................................................................................................ 140
Digital Inputs...........................................................................................................141
Input Interrupt Function ..........................................................................................142
Analog Inputs .......................................................................................................... 142
Extended I/O of the DMC-3425 Controller........................................................................... 143
Configuring the I/O of the DMC-3425.................................................................... 143
Saving the State of the Outputs in Non-Volatile Memory.......................................144
Accessing Extended I/O ..........................................................................................144
Interfacing to Grayhill or OPTO-22 G4PB24 .........................................................145
Example Applications............................................................................................................ 145
Wire Cutter.............................................................................................................. 145
A-B (X-Y) Table Controller....................................................................................146
Speed Control by Joystick....................................................................................... 148
Position Control by Joystick.................................................................................... 149
Chapter 8 Hardware & Software Protection 151
Introduction ...........................................................................................................................151
Hardware Protection .............................................................................................................. 151
Output Protection Lines........................................................................................... 151
Input Protection Lines ............................................................................................. 152
Software Protection ...............................................................................................................152
Example:.................................................................................................................. 152
Programmable Position Limits ................................................................................ 152
Example:.................................................................................................................. 153
Off-On-Error ...........................................................................................................153
Examples: ................................................................................................................ 153
Automatic Error Routine ......................................................................................... 153
Example:.................................................................................................................. 153
Limit Switch Routine ..............................................................................................154
Chapter 9 Troubleshooting 155
Overview ...............................................................................................................................155
Installation ............................................................................................................................. 155
Communication......................................................................................................................156
Stability.................................................................................................................................. 156
Operation ............................................................................................................................... 156
Chapter 10 Theory of Operation 157
Overview ...............................................................................................................................157
Operation of Closed-Loop Systems.......................................................................................159
System Modeling................................................................................................................... 160
Motor-Amplifier......................................................................................................161
Encoder....................................................................................................................163
DAC ........................................................................................................................164
Digital Filter ............................................................................................................ 164
ZOH......................................................................................................................... 165
System Analysis.....................................................................................................................165
System Design and Compensation.........................................................................................167
The Analytical Method............................................................................................ 167
DMC-3425 Contents• v
Appendices 171
Electrical Specifications ........................................................................................................171
Servo Control ..........................................................................................................171
Input/Output ............................................................................................................ 171
Power Requirements................................................................................................ 171
Performance Specifications ...................................................................................................171
Connectors for DMC-3425 .................................................................................................... 172
J3 DMC-3425 General I/O; 37- PIN D-type ........................................................... 172
J3 DMC-3425-Stepper General I/O; 37- PIN D-type.............................................. 173
J5 POWER; 6 PIN MOLEX.................................................................................... 173
J1 RS232 Main port: DB-9 Pin Male: ..................................................................... 174
Pin-Out Description............................................................................................................... 174
ICM-1460 Interconnect Module ............................................................................................ 175
Opto-Isolation Option for ICM-1460.....................................................................................177
Opto-isolated inputs: ...............................................................................................177
Opto-isolated outputs: .............................................................................................178
64 Extended I/O of the DMC-3425 Controller...................................................................... 179
Configuring the I/O of the DMC-3425 with DB-14064.......................................... 179
Connector Description:............................................................................................ 181
IOM-1964 Opto-Isolation Module for Extended I/O Controllers.......................................... 183
Description: ............................................................................................................. 183
Overview ................................................................................................................. 184
Configuring Hardware Banks.................................................................................. 185
Digital Inputs...........................................................................................................185
High Power Digital Outputs .................................................................................... 187
Standard Digital Outputs ......................................................................................... 188
Electrical Specifications .......................................................................................... 189
Relevant DMC Commands......................................................................................190
Screw Terminal Listing........................................................................................... 190
Coordinated Motion - Mathematical Analysis....................................................................... 193
List of Other Publications......................................................................................................196
Training Seminars.................................................................................................................. 196
Contacting Us ........................................................................................................................197
WARRANTY ........................................................................................................................ 198
Index 199
vi • Contents DMC-3425
Chapter 1 Overview
Introduction
The DMC-3425 provides a highly versatile, powerful form of distributed control where multiple DMC3425 controllers can be linked together on the Ethernet. One DMC-3425 is designated as a “master”
that receives all commands from the host computer and passes them to the other “slave” DMC-3425
controllers. Efficient, quick communications are realized as this approach eliminates the usual,
multiple communication links between the host computer and each controller.
Each DMC-3425 precisely controls two servo motors, providing ECAM, gearing and both linear and
circular interpolation for coordinated motion along the two local axis. A single axis DMC-3415 is also
available. When acting as the “master,” a DMC-3425 can receive PR, PA and JG commands for up to
eight axes and distribute them to the appropriate controller. Coordinated motion is commanded locally
by each DMC-3425 “slave” controller. Performance capability of these controllers includes: 12 MHz
encoder input frequency, 16-bit motor command output DAC, +/-2 billion counts total travel per move,
250 μsec minimum sample rate and non-volatile memory for program and parameter storage.
Designed for maximum flexibility, the DMC-3425 can be interfaced to a variety of motors and drives
including step motors, brush and brushless servo motors and hydraulics. The DMC-3425 can also be
configured to provide sinusoidal commutation for brushless motors.
The controller accepts feedback from a quadrature linear or rotary encoder with input frequencies up to
12 million quadrature counts per second. Modes of motion include jogging, point-to-point positioning,
electronic cam, electronic gearing and contouring. Several motion parameters can be specified
including acceleration and deceleration rates and slew speed. The DMC-3425 also provides motion
smoothing to eliminate jerk.
For synchronization with outside events, the DMC-3425 provides uncommitted I/O. The DMC-3425
provides up to 3 digital inputs, 3 digital outputs and 2 analog inputs. The DMC-3415 provides 7
digital inputs, 3 digital outputs and 2 analog inputs. Committed digital inputs are provided for forward
and reverse limits, abort, home, and definable input interrupts. An additional 64 configurable I/O
points may be added with the optional DB-14064 daughter card. The DMC-3425 distributed system
may also be linked with multiple IOC-7007 Ethernet I/O modules for complete machine I/O control.
Event triggers can automatically check for elapsed time, distance and motion complete.
The DMC-3425 is easy to program. Instructions are represented by two letter commands such as BG
for Begin and SP for Speed. Conditional instructions, Jump statements and arithmetic functions are
included for writing self-contained applications programs. An internal editor allows programs to be
quickly entered and edited, and support software such as the WSDK allows quick system set-up and
tuning. Commands may also be sent in Binary to decrease processing time.
To prevent system damage during machine operation, the DMC-3425 provides many error-handling
features. These include software and hardware limits, automatic shut-off on excessive error, abort
input and user-definable error and limit routines.
DMC-3425 Chapter 1 Overview• 1
The DMC-3425 is designed for stand-alone applications and provides non-volatile storage for
programs, variables and array elements.
This manual uses ‘DMC-3425’ to refer to the distributed control E-series from Galil. However, most
functions described in this manual are available using either the DMC-3425 or the DMC-3415. If a
function is specific to only one of the controllers, this will be explicitly stated.
Overview of Motor Types
The DMC-3425 can provide the following types of motor control:
1. Standard servo motors with +/- 10 volt command signals
2. Step motors with step and direction signals
3. Brushless servo motors with sinusoidal commutation
4. Other actuators such as hydraulics - For more information, contact Galil.
The user can configure each axis for any combination of motor types, providing maximum flexibility.
Standard Servo Motors with +/- 10 Volt Command Signal
The DMC-3425 achieves superior precision through use of a 16-bit motor command output DAC and a
sophisticated PID filter that features velocity and acceleration feedforward, an extra notch filter and
integration limits.
The controller is configured by the factory for standard servo motor operation. In this configuration,
the controller provides an analog signal (+/- 10Volt) to connect to a servo amplifier. This connection
is described in Chapter 2.
Stepper Motor with Step and Direction Signals
The DMC-3425 can control 2 stepper motors. In this mode, the controller provides two signals to
connect to each stepper motor: Step and Direction. For stepper motor operation, the controller does
not require an encoder and operates the stepper motor in an open loop. Chapter 2 describes the proper
connection and procedure for using stepper motors.
NOTE: In order to use two stepper motors on the DMC-3425, the controller must be ordered as a
DMC-3425-Stepper. In this mode, the Amp Enable and Error outputs are converted to the Step and
Direction signals for the Y-axis. Contact Galil for other stepper options.
Brushless Servo Motor with Sinusoidal Commutation
The DMC-3415 can provide sinusoidal commutation for brushless motors (BLM). In this
configuration, the controller generates two sinusoidal signals for connection with amplifiers
specifically designed for this purpose. Please note, for a 2 axis DMC-3425, converting to a brushless
motor uses up the second axis.
Note: The task of generating sinusoidal commutation may be accomplished in the brushless motor
amplifier. If the amplifier generates the sinusoidal commutation signals, only a single command signal
is required and the controller should be configured for a standard servo motor (described above).
Sinusoidal commutation in the controller can be used with linear and rotary BLMs. However, the
motor velocity should be limited such that a magnetic cycle lasts at least 6 milliseconds*. For faster
motors, please contact the factory.
The controller provides a one-time, automatic set-up procedure. The parameters determined by this
procedure can then be saved in non-volatile memory to be used whenever the system is powered on.
2 • Chapter 1 Overview DMC-3425
The DMC-3415 can control BLMs equipped with Hall sensors as well as without Hall sensors. If hall
sensors are available, once the controller has been setup, the controller will estimate the commutation
phase upon reset. This allows the motor to function immediately upon power up. The Hall effect
sensors also provide a method for setting the precise commutation phase. Chapter 2 describes the
proper connection and procedure for using sinusoidal commutation of brushless motors.
* 6 Milliseconds per magnetic cycle assumes a servo update of 1 msec (default rate).
DMC-3425 Chapter 1 Overview• 3
DMC-3425 Functional Elements
The DMC-3425 circuitry can be divided into the following functional groups as shown in Figure 1.1
and discussed below.
ETHERNET
RS-232
WATCHDOG TIMER
68331
MICROCOMPUTER
WITH
1 Meg RAM
4 Meg FLASH EEPROM
HIGH-SPEED
MOTOR/ENCODER
INTERFACE
ISOLATED LIMITS AND
HOME INPUTS
MAIN ENCODERS
AUXILIARY ENCODERS
+/- 10 VOLT OUTPUT FOR
SERVO MOTORS
PULSE/DIRECTION OUTPUT
FOR STEP MOTORS
I/O INTERFACE
2 UNCOMMITTED
ANALOG INPUTS
HIGH-SPEED LATCH FOR EACH AXIS
3 PROGRAMMABLE,
INPUTS
3 PROGRAMMABLE
OUTPUTS
HIGH SPEED ENCODER
COMPARE OUTPUT
Figure 1.1 - DMC-3425 Functional Elements
Microcomputer Section
The main processing unit of the DMC-3425 is a specialized 32-bit Motorola 68331 Series
Microcomputer with 1 Meg RAM and 4 Meg Flash EEPROM. The RAM provides memory for
variables, array elements and application programs. The flash EEPROM provides non-volatile storage
of variables, programs, and arrays. It also contains the DMC-3425 firmware.
Motor Interface
Galil’s GL-1800 custom, sub-micron gate array performs quadrature decoding of each encoder at up to
12 MHz. For standard servo operation, the controller generates a +/-10 Volt analog signal (16 Bit
DAC). For sinusoidal commutation operation, the controller uses two DACs to generate two +/-10Volt
analog signals. For stepper motor operation, the controller generates a step and direction signal.
Communication
The communication interface with the DMC-3425 consists of one RS-232 port (19.2 kbaud) and one
10base-T Ethernet port.
4 • Chapter 1 Overview DMC-3425
General I/O
A
The DMC-3415 provides interface circuitry for 7 TTL inputs and 3 TTL outputs. In addition, the
controller provides two 12-bit analog inputs. The general inputs can also be used for triggering a highspeed positional latch for each axis.
NOTE: In order to accommodate 2 axes on the DMC-3425, many of the general I/O features become
dedicated I/O for the second axis. The standard DMC-3425 will have 3 TTL inputs, 3 TTL outputs and
2 analog inputs. If extra I/O is needed, the DB-14064 I/O daughter card increases general purpose I/O
by 64 points.
System Elements
As shown in Fig. 1.2, the DMC-3425 is part of a motion control system, which includes amplifiers,
motors and encoders. These elements are described below.
Computer DMC-3425 Controller
Encoder Motor
Figure 1.2 - Elements of Servo systems
Power Supply
mplifier (Driver)
Motor
A motor converts current into torque, which produces motion. Each axis of motion requires a motor
sized properly to move the load at the required speed and acceleration. (Galil's "Motion Component
Selector" software can help you with motor sizing). Contact Galil for more information.
The motor may be a step or servo motor and can be brush-type or brushless, rotary or linear. For step
motors, the controller is capable of controlling full-step, half-step, or microstep drives. An encoder is
not required when step motors are used.
Amplifier (Driver)
For each axis, the power amplifier converts a +/-10 Volt signal from the controller into current to drive
the motor. For stepper motors, the amplifier converts step and direction signals into current. The
amplifier should be sized properly to meet the power requirements of the motor. For brushless motors,
an amplifier that provides electronic commutation is required or the controller must be configured to
provide sinusoidal commutation. The amplifiers may be either pulse-width-modulated (PWM) or
linear. They may also be configured for operation with or without a tachometer. For current
amplifiers, the amplifier gain should be set such that a 10 Volt command generates the maximum
required current. For example, if the peak motor current is 10A, the amplifier gain should be 1 A/V.
For velocity mode amplifiers, 10 Volts should run the motor at the maximum speed.
DMC-3425 Chapter 1 Overview• 5
For step motors, the amplifiers should accept step and direction signals.
Encoder
An encoder translates motion into electrical pulses that are fed back into the controller. The DMC-3425
accepts feedback from either a rotary or linear encoder. Typical encoders provide two channels in
quadrature, known as CHA and CHB. This type of encoder is known as a quadrature encoder.
Quadrature encoders may be either single-ended (CHA and CHB) or differential (CHA,CHA-,
CHB,CHB-). The DMC-3425 decodes either type into quadrature states or four times the number of
cycles. Encoders may also have a third channel (or index) for synchronization. The DMC-3425 can
also interface to encoders with pulse and direction signals.
There is no limit on encoder line density; however, the input frequency to the controller must not
exceed 3,000,000 full encoder cycles/second (12,000,000 quadrature counts/sec). For example, if the
encoder line density is 10000 cycles per inch, the maximum speed is 300 inches/second. If higher
encoder frequency is required, please consult the factory.
The standard voltage level is TTL (zero to five volts), however, voltage levels up to 12 Volts are
acceptable. (If using differential signals, 12 Volts can be input directly to the DMC-3425. Singleended 12 Volt signals require a bias voltage input to the complementary inputs.)
The DMC-3425 can accept analog feedback instead of an encoder for any axis. For more information
see description of analog feedback in the Command Reference under the AF command.
To interface with other types of position sensors such as resolvers or absolute encoders, Galil can
customize the controller and command set. Please contact Galil to talk to one of our applications
engineers about your particular system requirements.
Watch Dog Timer
The DMC-3425 provides an internal watch dog timer which checks for proper microprocessor
operation. The timer toggles the Amplifier Enable Output (AEN), which can be used to switch the
amplifiers off in the event of a serious DMC-3425 failure. The AEN output is normally high. During
power-up and if the microprocessor ceases to function properly, the AEN output will go low. The
error light for each axis will also turn on at this stage. A reset is required to restore the DMC-3425 to
normal operation. Consult the factory for a Return Materials Authorization (RMA) number if your
DMC-3425 is damaged.
6 • Chapter 1 Overview DMC-3425
Chapter 2 Getting Started
The DMC-3425 Motion Controller
+5V/Gnd Test
Points
6 Pin Molex
Power Connector
Distributed Control Axis
configuration jumpers
Step/Direction or
Motor Command
configuration jumpers
Stepper motor/Motor off
configuration jumpers
+5 G
+12 +5 +5 G G -12
J5
JP3
SD MC
+12V/-12V Test
Points
JP2
+12-12
*
DMC-1415
MO
SMX
SMY
REV D
U1
Motorola
68331
J4
A8
A4
A2
A1
Daughter card connector for
DB-14064 Extended I/O card
U4
GALIL MOTION CONTROL
MADE IN USA
GL-1800
U10
RAM
9-Pin DSub
J6
J1
U2
JP1
1200
9600
MRST
UPGD
J3
J2
D2
D4
SW1
RS232 serial port
Ethernet
network IC
Master reset/baud
rate jumpers
Reset switch
RJ-45 10BaseT
Ethernet connector
Main 37-pin DSub
connector
Status/Communications
LED's
Figure 2.1 – Outline of the DMC-3425
DMC-3425 Chapter 2 Getting Started• 7
Elements You Need
Before you start, you must get all the necessary system elements. These include:
1. (1) DMC-3425 or DMC-3415, (1) 37-pin cable (order Cable -37).
2. Servo motor(s) with encoders or stepper motors.
3. Appropriate motor drive - servo amp (Power Amplifier or AMP-1460) or stepper drive.
4. Power Supply for Amplifier
5. +5V, ±12V supply for DMC-3425
6. Communication CD from Galil
7. WSDK Servo Design Software (not necessary, but strongly recommended)
8. Interface Module ICM-1460 with screw-type terminals or integrated Interface
Module/Amplifier, AMP-1460. (Note: An interconnect module is not necessary, but strongly
recommended.) Also, the AMP-1460 only provides for 1 axis power amplification.
The motors may be servo (brush or brushless type) or steppers. The driver (amplifier) should be
suitable for the motor and may be linear or pulse-width-modulated and it may have current feedback or
voltage feedback.
For servo motors, the drivers should accept an analog signal in the +/-10 Volt range as a command.
The amplifier gain should be set so that a +10V command will generate the maximum required current.
For example, if the motor peak current is 10A, the amplifier gain should be 1 A/V. For velocity mode
amplifiers, a command signal of 10 Volts should run the motor at the maximum required speed.
For step motors, the driver should accept step and direction signals. For start-up of a step motor
system refer to Step 8c “Connecting Step Motors”.
The WSDK software is highly recommended for first time users of the DMC-3425. It provides stepby-step instructions for system connection, tuning and analysis.
Installing the DMC-3425 Controller
Installation of a complete, operational DMC-3425 system consists of 9 steps.
Step 1. Determine overall motor configuration.
Step 2. Configuring jumpers on the DMC-3425.
Step 3. Connect the DC power supply and serial cable to the DMC-3425.
Step 4. Install the communications software.
Step 5. Establish communications between the DMC-3425 and the host PC.
Step 6. Set-up axis for sinusoidal commutation.
Step 7. Make connections to amplifier and encoder.
Step 8a. Connect standard servo motor.
Step 8b. Connect brushless motor for sinusoidal commutation.
Step 8c. Connect step motor.
Step 9. Tune servo system.
Step 10. Configure distributed control system.
8 • Chapter 2 Getting Started DMC-3425
Step 1. Determine Overall Motor Configuration
Before setting up the motion control system, the user must determine the desired motor configuration.
The DMC-3425 can control standard brush or brushless servo motors, sinusoidally commutated
brushless motors or stepper motors. For control of other types of actuators, such as hydraulics, please
contact Galil. The following configuration information is necessary to determine the proper motor
configuration:
Standard Servo Motor Operation:
The DMC-3425 has been setup by the factory for standard servo motor operation providing an analog
command signal of +/- 10 volt. The position of the jumpers at JP2/JP3 determines the type of output
the controllers will provide, analog motor command or PWM output. The installation of these jumpers
is discussed in the section “Configuring Jumpers on the DMC-3425”. Figure 2.2 shows how the
jumpers are configured for the standard output mode.
The DMC-3425 controller will output the analog command signal to either brush or brushless servo
amplifiers. Please note that if the brushless amplifier provides the sinusoidal commutation, the
standard servo motor operation from the controller will be used. If the commutation is to be performed
by the controller, please see below.
Sinusoidal Commutation:
Please consult the factory before operating with sinusoidal commutation.
Sinusoidal commutation is configured through a single software command, BA. This setting causes
the controller to reconfigure the control axis to output two commutated phases. The DMC-3425
requires two DAC outputs for a single axis of commutation. Issuing the BA command will enable the
second DAC for commutation.
If a DMC-3425 is used for sinusoidal commutation, the second axis will be used for the second DAC
phase. Please note that if the DMC-3425 is used for sinusoidal commutation, it will still be
represented by two axes within the distributed system, even though only one axis is truly active. The
DMC-3415 in brushless mode will take only a single axis within the distributed system.
Further instruction for sinusoidal commutation connections are discussed in Step 6.
Stepper Motor Operation:
The DMC-3415 can be configured to operate in stepper mode by installing a hardware jumper and
issuing a software command. The DMC-3425 can be configured to operate with two stepper motors by
ordering the DMC-3425-Stepper option from the factory. To configure the DMC-3425 for stepper
motor operation, the controller requires a jumper for the stepper motors and the command, MT, must
be given. The installation of the stepper motor jumper is discussed in the following section entitled
"Configuring Jumpers on the DMC-3425". Further instructions for stepper motor connections are
discussed in Step 8b.
Step 2. Configuring Jumpers on the DMC-3425
Master Reset and Upgrade Jumper
JP1 contains two jumpers, MRST and UPGD. The MRST jumper is the Master Reset jumper. When
MRST is connected, the controller will perform a master reset upon PC power up or upon the reset
input going low. Whenever the controller has a master reset, all programs, arrays, variables, and
motion control parameters stored in EEPROM will be ERASED.
The UPGD jumper enables the user to unconditionally update the controller’s firmware. This jumper
is not necessary for firmware updates when the controller is operating normally, but may be necessary
in cases of corrupted EEPROM. EEPROM corruption should never occur, however, it is possible if
DMC-3425 Chapter 2 Getting Started• 9
there is a power fault during a firmware update. If EEPROM corruption occurs, your controller may
not operate properly. In this case, install the UPGD Jumper and use the update firmware function on
the Galil Smart Terminal or WSDK to re-load the system firmware.
Setting the Baud Rate on the DMC-3425
The jumpers labeled “9600” and “1200” at JP1 allow the user to select the serial communication baud
rate. The baud rate can be set using the following table:
JUMPER SETTINGS BAUD RATE
9600 1200 --
OFF OFF 19200
ON OFF 9600
OFF ON 1200
The default baud rate for the controller is 19.2k.
Selecting MO as default on the DMC-3425
The default condition for the motor on the DMC-3425 is the servo on (SH) state. This will enable the
amplifiers upon power up of the controller. This state can be changed to the motor off (MO) default by
placing a jumper at JP2 across the MO terminals. This will power up the controller with the amplifiers
disabled and the motor command off. The SH command must then be given in order for the servos or
steppers to operate.
Stepper Motor Jumpers
The DMC-3415 is user configurable to control either a servo motor or a stepper motor. The DMC3425 is factory default to servo control, but may also control two steppers if ordered from the factory
as a DMC-3425-Stepper.
To configure the DMC-3415 for stepper output, two jumpers must be placed on the controller. First,
the SMX jumper at location JP2 must be installed. This configures the board for step/direction output.
Second, the jumpers at location JP3 must be moved from the MC position to the SD position as shown
in Figure 2.2. This configures the output pins on the controller to output step and direction instead of
the analog motor command.
The configuration for two stepper motors on the DMC-3425-Stepper is handled at the factory. The
same procedure is used, placing jumpers on SMX and SMY at location JP2, and moving the SD/MC
jumpers at location JP3. A board modification is also required, which should only be handled by Galil
technicians.
JP3
MCSD
Setting for analog motor command Setting for step/direction output
MC SD
JP3
Figure 2.2 - Jumper settings for motor command output
10 • Chapter 2 Getting Started DMC-3425
Axis Configuration Jumpers
When using the HC automatic configuration, jumpers must be set to indicate which controller is the
master and which controllers are slaves. Depending on the configuration of the jumpers, a controller
will be set up as either the A (B) master or any of the axes slaves.
The 8-pin jumper, found at location J4 next to the Molex power connector, is used to select axes
configurations. Jumpers at this location are labeled A1, A2, A4 and A8, which represent the binary
value for each of the 8 axes within a system. The following chart shows proper jumper selection for
each of the DMC-3415 or DMC-3425’s in a system.
Master A (B) axis No Jumpers
Slave Axis B A1 On A2 Off A4 Off A8 Off
Slave Axes C A1 Off A2 On A4 Off A8 Off
Slave Axis D A1 On A2 On A4 Off A8 Off
Slave Axes E A1 Off A2 Off A4 On A8 Off
Slave Axis F A1 On A2 Off A4 On A8 Off
Slave Axes G A1 Off A2 On A4 On A8 Off
Slave Axis H A1 On A2 On A4 On A8 Off
Jumpers on a card are used to denote the first axis it represents in a system. Therefore, a DMC-3415
takes up a single jumper setting. A DMC-3425 is selected with a single jumper setting but represents
two axes.
For example, the jumper settings for a system with a DMC-3415 master A axis, a DMC-3425 slave BC
axis and a DMC-3415 slave D axis, the following jumper settings would be used.
Master A – No Jumpers
Slave Axis BC – A1 On A2 Off A4 Off A8 Off
Slave Axis D – A1 On A2 On A4 Off A8 Off
A1 A2 A4
Fig. 2.3 – Example jumper settings for DMC-3425 E, F axis configuration.
A8
Step 3. Connecting AC or DC power and the Serial Cable to the DMC-3425
1. Insert 37-pin cable to J3. Connect the other end of the cable to the ICM-1460.
2. If using serial communications, use the 9-pin RS232 ribbon cable to connect the SERIAL port
of the DMC-3425 to your computer or terminal communications port. The DMC-3425 serial
DMC-3425 Chapter 2 Getting Started• 11
port is configured as DATASET. Your computer or terminal must be configured as a
DATATERM for full duplex, no parity, 8 bits data, one start bit and one stop bit.
Your computer needs to be configured as a "dumb" terminal that sends ASCII characters as
they are typed to the DMC-3425.
Connections to the controller for Ethernet communication are covered in Step 5.
3. If using the card level version, apply ±12V and +5V power to the J5 connector. If using the
box level version, connect the AC cord to a power outlet. AC power requirements for the
controller are single phase, 50 or 60 Hz at 90 to 260 VAC.
4. Applying power will turn on the green LED power indicator.
Step 4. Installing the Communications Software
After applying power to the computer, you should install the Galil software that enables
communication between the controller and PC.
Using DOS:
Using the Galil Software CD-ROM, go to the directory, DMCDOS. Type "INSTALL" at the DOS
prompt and follow the directions.
Using Windows 3.x (16 bit versions):
Using the Galil Software CD ROM, go to the directory, DMCWIN16. Run DMCWIN16.exe at the
Command prompt and follow the directions.
Using Windows 95, NT or 98 (32 bit versions):
The Galil Software CD-ROM will automatically begin the installation procedure when the CD-ROM is
installed. After installing the Galil CD-ROM software on your computer, you can easily install other
software components as desired. To install the basic communications software, run the Galil Software
CD-ROM and choose “DMC Smart Terminal”. This will install the Galil Terminal that can be used
for communication.
Step 5. Establishing Communication between the DMC-3425 and the host PC
Note: This section will show how to communicate with a single DMC-3425 or DMC-3415 controller.
If the controllers will be configured in a multi-axis, distributed control system, only the master axis
needs an IP address actively configured.
Communicating through the RS-232 Serial Communications Port
Connect the DMC-3425 serial port to your computer via the Galil CABLE-9PIN-D (RS-232 Cable).
Using Galil Software for DOS
To communicate with the DMC-3425, type TALK2DMC at the prompt. Once you have established
communication, the terminal display should show a colon, :. If you do not receive a colon, press the
carriage return. If a colon prompt is not returned, there is most likely an incorrect setting of the serial
communications port. The user must ensure that the correct communication port and baud rate are
specified when attempting to communicate with the controller. Please note that the serial port on the
controller must be set for handshake mode for proper communication with Galil software. The user
must also insure that the proper serial cable is being used. See appendix for pin-out of serial port.
12 • Chapter 2 Getting Started DMC-3425
Using Galil Software for Windows
In order for the Windows software to communicate with a Galil controller, the controller must be
registered in the Windows Registry. To register a controller, you must specify the model of the
controller, the communication parameters, and other information. The registry is accessed through the
Galil software, such as WSDK or DMCSmartTerm.
The registry window is equipped with a button to Add a New Controller, change the Properties of an
existing controller, Delete a controller, or Find an Ethernet controller.
Use the New Controller button to add a new entry to the Registry. Use the Properties button to
change the properties of a current controller. For a new registration, you will need to supply the Galil
Controller type. The controller model number must be entered. If you are changing an existing
controller, this field will already have an entry. Pressing the down arrow to the right of this field will
reveal a menu of valid controller types. Once the DMC-3425 has been selected, there is a choice for
either Serial or Ethernet communication, as shown below. Select Serial communication.
DMC-3425 Chapter 2 Getting Started• 13
After selecting Next, the registry information will show a default Comm Port of 1 and a default Comm
Speed of 19200 appears. This information should be changed as necessary to reflect the computers
Comm Port and the baud rate set by the controller's baud rate jumpers.
Once you have set the appropriate Registry information for your controller, Select Finish and close the
registry window. You will now be able to communicate with the DMC-3425. Within WSDK, select
File and Connect to Controller. Within DMCSmartTerm, select Tools and Select Controller. Once
14 • Chapter 2 Getting Started DMC-3425
the entry has been selected, click on the OK button. If the software has successfully established
communications with the controller, the registry entry will be displayed at the top of the screen.
If you are not properly communicating with the controller, the program will pause for 3-15 seconds.
The top of the screen will display the message “Status: not connected with Galil motion controller” and
the following error will appear: “STOP - Unable to establish communication with the Galil controller.
A time-out occurred while waiting for a response from the Galil controller.” If this message appears,
you must click OK. In this case, there is most likely an incorrect setting of the serial communications
port. The user must ensure that the correct communication port and baud rate are specified when
attempting to communicate with the controller. Please note that the serial port on the controller must
be set for handshake mode for proper communication with Galil software. The user must also insure
that the proper straight-through serial cable is being used (no Null modem). See appendix for the
correct pin-outs for the serial cable.
Once you establish communications, click on the menu for terminal and you will receive a colon
prompt. Communicating with the controller is described in later sections.
Using Non-Galil Communication Software
The DMC-3425 serial port is configured as DATASET. Your computer or terminal must be
configured as a DATATERM for full duplex, no parity, 8 data bits, one start bit and one stop bit.
Check to insure that the baud rate switches have been set to the desired baud rate as described above.
Your computer needs to be configured as a "dumb" terminal that sends ASCII characters as they are
typed to the DMC-3425. Use the EO command to specify if the characters should be echoed back
from the controller.
Sending Test Commands to the Terminal:
After you connect your terminal, press <carriage return> or the <enter> key on your keyboard. In
response to carriage return (CR), the controller responds with a colon, :
Now type
TPA (CR)
This command directs the controller to return the current position of the A axis. The controller should
respond with a number such as
0000000
Communicating through the Ethernet
For Ethernet communication, connect the DMC-3425 to your computer or to a hub. If connecting
through a switch or a hub, a standard RJ45 Ethernet cable is used. If connecting directly to the PC, a
cross-over RJ45 Ethernet cable must be used.
Using Galil Software for Windows
The controller must be registered in the Galil Windows registry for the host computer to communicate
with it. The registry may be accessed via Galil software, such as WSDK or DMCSmartTerm.
From WSDK, the registry is accessed under the FILE menu. From DMCSmartTerm it is accessed
under the Tools and Controller Registration menu. In the Galil Registry, the DMC-3425 can either
be added manually with the New Controller button or the software can automatically try to find the
controller with the Find Ethernet Controller button.
The first registry option is to use the New Controller button. The DMC-3425 should be selected from
the models listed, with Ethernet selected as the mode of communication.
DMC-3425 Chapter 2 Getting Started• 15
After Next is pressed, the next screen will allow the IP address to be selected and assigned.
Enter the IP address obtained from your system administrator into the box IP Address. Select the
button corresponding to the protocol in which you wish to communicate with the controller, UDP or
TCP. If the IP address has not been already assigned to the controller, click on ASSIGN IP
ADDRESS.
16 • Chapter 2 Getting Started DMC-3425
ASSIGN IP ADDRESS will check the controllers that are linked to the network to see which ones do
not have an IP address. The program will then ask you whether you would like to assign the IP
address you entered to the controller with the specified serial number. Click on YES to assign it, NO
to move to next controller, or CANCEL to not save the changes. If there are no controllers on the
network that do not have an IP address assigned, the program will state this. Once the correct
controller has been selected, click on Finish.
If an IP address has already been assigned to the controller through the serial port and the IA
command, add this address to the IP Address box and then select Finish.
The second method for registering the controller is by using the option within the registry labeled Find
Ethernet Controllers. This utility uses the DMCNet software program to search for any controllers
on the network, both with and without IP addresses. If the DMC-3425 does not have an IP address, the
utility will listen for the BOOTP packet and then ask for an IP address to be assigned. Once the IP
address is added, click on Register and the controller will be added to the Galil Registry. If an IP
address has already been assigned to the controller, the utility will list that controller with its current IP
address. At this point, click on Register and the controller will be added to the Galil Registry.
Once you have set the appropriate Registry information for your controller, Select Close to close the
registry window. You will now be able to communicate with the DMC-3425. Within WSDK, select
File and Connect to Controller. Within DMCSmartTerm, select Tools and Select Controller. Once
the appropriate entry has been selected, click on the OK button. If the software has successfully
established communications with the controller, the registry entry will be displayed at the top of the
screen.
See Chapter 4 Communication for additional information on the Ethernet configuration and
connection.
Sending Test Commands to the Terminal:
After you connect your terminal, press <return> or the <enter> key on your keyboard. In response to
carriage return <return>, the controller responds with a colon, :
Now type
TPA <return>
This command directs the controller to return the current position of the A axis. The controller should
respond with a number such as
0000000
Step 6. Set-up axis for sinusoidal commutation (optional)
* This step is only required when the controller will be used to control a brushless motor with
sinusoidal commutation. Please consult the factory before operating with sinusoidal commutation.
The command BA is used to specify sinusoidal commutation mode for the DMC-3415 or DMC-3425.
In this mode the controller will output two sinusoidal phases for the DACs. Once specified, follow the
procedure outlined in Step 8b.
Step 7. Make connections to amplifier and encoder
Once you have established communications between the software and the DMC-3425, you are ready to
connect the rest of the motion control system. The motion control system generally consists of an
ICM-1460 Interface Module, a servo amplifier, and a motor to transform the current from the servo
amplifier into torque for motion. Galil also offers the AMP-1460 Interface Module which is an ICM1460 equipped with a servo amplifier for a DC motor.
DMC-3425 Chapter 2 Getting Started• 17
A signal breakout board of some type is strongly recommended. If you are using a breakout board
from a third party, consult the documentation for that board to insure proper system connection.
If you are using the ICM-1460 or AMP-1460 with the DMC-3425, connect the 37-pin cable between
the controller and interconnect module.
Here are the first steps for connecting a motion control system:
Step A. Connect the motor to the amplifier with no connection to the controller. Consult the
amplifier documentation for instructions regarding proper connections. Connect and
turn on the amplifier power supply. If the amplifiers are operating properly, the
motor should stand still even when the amplifiers are powered up.
Step B. Connect the amplifier enable signal. Before making any connections from the
amplifier to the controller, you need to verify that the ground level of the amplifier is
either floating or at the same potential as earth.
Note: If you are using a DMC-3425-Stepper, the amplifier enable signal is used for
the second stepper output.
WARNING: When the amplifier ground is not isolated from the power line or when it has a different potential
than that of the computer ground, serious damage may result to the computer controller and amplifier.
If you are not sure about the potential of the ground levels, connect the two ground
signals (amplifier ground and earth) by a 10 kΩ resistor and measure the voltage
across the resistor. Only if the voltage is zero, proceed to connect the two ground
signals directly.
The amplifier enable signal is used by the controller to disable the motor. This
signal is labeled AMPEN on the ICM-1460 and should be connected to the enable
signal on the amplifier. Note that many amplifiers designate this signal as the
INHIBIT signal. Use the command, MO, to disable the motor amplifiers - check to
insure that the motor amplifiers have been disabled (often this is indicated by an
LED on the amplifier).
This signal changes under the following conditions: the watchdog timer activates,
the motor-off command, MO, is given, or the OE1 command (Enable Off-On-Error)
is given and the position error exceeds the error limit. As shown in Figure 3.1, AEN
can be used to disable the amplifier for these conditions.
The standard configuration of the AEN signal is TTL active high. In other words,
the AEN signal will be high when the controller expects the amplifier to be enabled.
The polarity and the amplitude can be changed if you are using the ICM-1460
interface board. To change the polarity from active high (5 volts = enable, zero volts
= disable) to active low (zero volts = enable, 5 volts = disable), replace the 7407 IC
with a 7406. Note that many amplifiers designate the enable input as ‘inhibit’.
To change the voltage level of the AEN signal, note the state of the JP1 jumper on
the ICM-1460. When the jumper is placed across 5V and AEN, the output voltage is
0-5V. To change to 12 volts, pull the jumper and rotate it so that +12V is connected
to AEN. If you remove the jumper, the output signal is an open collector, allowing
the user to connect an external supply with voltages up to 24V.
Step C. Connect the encoders
For stepper motor operation, an encoder is optional.
For servo motor operation, if you have a preferred definition of the forward and
reverse directions, make sure that the encoder wiring is consistent with that
definition.
18 • Chapter 2 Getting Started DMC-3425
The DMC-3425 accepts single-ended or differential encoder feedback with or
without an index pulse. If you are not using the AMP-1460 or the ICM-1460, you
will need to consult the appendix for the encoder pinouts for connection to the
motion controller. The AMP-1460 and the ICM-1460 can accept encoder feedback
from a 10-pin ribbon cable or individual signal leads. For a 10-pin ribbon cable
encoder, connect the cable to the protected header connector labeled JP2. For
individual wires, simply match the leads from the encoder you are using to the
encoder feedback inputs on the interconnect board. The signal leads are labeled
CHA, CHB, and INDEX. These labels represent channel A, channel B, and the
INDEX pulse, respectively. For differential encoders, the complement signals are
labeled CHA-, CHB-, and INDEX-.
Note: When using pulse and direction encoders, the pulse signal is connected to
CHA and the direction signal is connected to CHB. The controller must be
configured for pulse and direction with the command CE. See the command
summary for further information on the command CE.
Step D. Verify proper encoder operation.
Once the encoder is connected as described above, turn the motor shaft and
interrogate the position with the instruction TP <return>. The controller response
will vary as the motor is turned.
At this point, if TP does not vary with encoder rotation, there are three possibilities:
1. The encoder connections are incorrect - check the wiring as necessary.
2. The encoder has failed - using an oscilloscope, observe the encoder signals.
Verify that both channels A and B have a peak magnitude between 5 and 12
volts. Note that if only one encoder channel fails, the position reporting varies
by one count only. If the encoder failed, replace the encoder. If you cannot
observe the encoder signals, try a different encoder.
3. There is a hardware failure in the controller - connect the same encoder to a
different axis. If the problem disappears, you probably have a hardware failure.
Consult the factory for help.
Step E. Connect Hall Sensors if available (sinusoidal commutation only)
Please consult factory before operating with sinusoidal commutation. Hall sensors
are only used with sinusoidal commutation on the DMC-3415 or DMC-3425 and are
not necessary for proper operation. The use of hall sensors allows the controller to
automatically estimate the commutation phase upon reset and also provides the
controller the ability to set a more precise commutation phase. Without hall sensors,
the commutation phase must be determined manually.
The Hall effect sensors are connected to the digital inputs of the controller. These
inputs can be used with the general-purpose inputs (bits 1 - 7). If you are using the
DMC-3425, only the first 3 inputs are available for general purpose.
Each set of inputs must use inputs that are in consecutive order. The input lines are
specified with the command, BI. For example, if the Hall sensors are connected to
inputs 1, 2 and 3, use the instruction:
BI1 <CR>
Step 8a. Connect Standard Servo Motor
The following discussion applies to connecting the DMC-3425 controller to standard servo motor
amplifiers:
DMC-3425 Chapter 2 Getting Started• 19
The motor and the amplifier may be configured in the torque or the velocity mode. In the torque
mode, the amplifier gain should be such that a 10 Volt signal generates the maximum required current.
In the velocity mode, a command signal of 10 Volts should run the motor at the maximum required
speed.
Step by step directions on servo system setup are also included on the WSDK (Windows Servo Design
Kit) software offered by Galil. See section on WSDK for more details.
Check the Polarity of the Feedback Loop
It is assumed that the motor and amplifier are connected together and that the encoder is operating
correctly (Step D). Before connecting the motor amplifiers to the controller, read the following
discussion on setting Error Limits and Torque Limits.
Step A. Set the Error Limit as a Safety Precaution
Usually, there is uncertainty about the correct polarity of the feedback. The wrong
polarity causes the motor to run away from the starting position. Using a terminal
program, such as DMCSmartTerm, the following parameters can be given to avoid
system damage:
Input the commands:
ER 2000,2000 <CR> Sets error limit to be 2000 counts
OE 1,1 <CR> Disables amplifier when excess error exists
If the motor runs away and creates a position error of 2000 counts, the motor
amplifier will be disabled.
Note: This function requires the AEN signal to be connected from the controller to
the amplifier.
Step B. Setting Torque Limit as a Safety Precaution
To limit the maximum voltage signal to your amplifier, the DMC-3425 controller has
a torque limit command, TL. This command sets the maximum voltage output of the
controller and can be used to avoid excessive torque or speed when initially setting
up a servo system.
When operating an amplifier in torque mode, the voltage output of the controller will
be directly related to the torque output of the motor. The user is responsible for
determining this relationship using the documentation of the motor and amplifier.
The torque limit can be set to a value that will limit the motors output torque.
When operating an amplifier in velocity or voltage mode, the voltage output of the
controller will be directly related to the velocity of the motor. The user is responsible
for determining this relationship using the documentation of the motor and amplifier.
The torque limit can be set to a value that will limit the speed of the motor.
For example, the following command will limit the output of the controller to 1 volt:
TL 1 <CR> Sets torque limit to 1 Volt on A axis
Note: Once the correct polarity of the feedback loop has been determined, the torque
limit should, in general, be increased to the default value of 9.99. The servo will not
operate properly if the torque limit is below the normal operating range. See
description of TL in the command reference.
Step C. Disable motor
Issue the motor off command to disable the motor.
MO <CR> Turns motor off
Step D. Connecting the Motor
20 • Chapter 2 Getting Started DMC-3425
Once the parameters have been set, connect the analog motor command signal
(ACMD) to the amplifier input.
Issue the servo here command to turn the motors on. To test the polarity of the
feedback, command a move with the instruction:
SH <CR> Servo Here to turn motors on
PR 1000 <CR> Position relative 1000 counts
BG <CR> Begin motion
When the polarity of the feedback is wrong, the motor will attempt to run away. The
controller should disable the motor when the position error exceeds 2000 counts. In
this case, the polarity of the loop must be inverted.
Inverting the Loop Polarity
When the polarity of the feedback is incorrect, the user must invert the loop polarity and this may be
accomplished by several methods. If you are driving a brush-type DC motor, the simplest way is to
invert the two motor wires (typically red and black). For example, switch the M1 and M2 connections
going from your amplifier to the motor. When driving a brushless motor, the polarity reversal may be
done with the encoder. If you are using a single-ended encoder, interchange the signal CHA and CHB.
If, on the other hand, you are using a differential encoder, interchange only CHA+ and CHA-. The
loop polarity and encoder polarity can also be affected through software with the MT, and CE
commands. For more details on the MT command or the CE command, see the Command Reference
section.
Sometimes the feedback polarity is correct (the motor does not attempt to run away) but the direction
of motion is reversed with respect to the commanded motion. If this is the case, reverse the motor
leads AND the encoder signals.
If the motor moves in the required direction but stops short of the target, it is most likely due to
insufficient torque output from the motor command signal ACMD. This can be alleviated by reducing
system friction on the motors. The instruction:
TT <CR> Tell torque
reports the level of the output signal. It will show a non-zero value that is below the friction level.
Once you have established that you have closed the loop with the correct polarity, you can move on to
the compensation phase (servo system tuning) to adjust the PID filter parameters, KP, KD and KI. It is
necessary to accurately tune your servo system to ensure fidelity of position and minimize motion
oscillation as described in the next section.
DMC-3425 Chapter 2 Getting Started• 21
J2
ICM-1460
Encoder lines
Power Supply
VAMP+
AMPGND
Motor 1
Motor
Motor 2
Figure 2.3 - System Connections with the AMP-1460 Amplifier
22 • Chapter 2 Getting Started DMC-3425
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