RoboteQ AX500 User Manual
AX500
Dual Channel
Digital Motor
Controller
User’s Manual
v1.9b, June 1, 2007
visit www.roboteq.com to download the latest revision of this manual
©Copyright 2003-2007 Roboteq, Inc.
2 AX500 Motor Controller User’s Manual Version 1.9b. June 1, 2007
Revision History
Revision History
Date Version Changes
June 1, 2007 1.9b Added Output C active when Motors On
Fixed Encoder Limit Switches
Protection in case of Encoder failure in Closed Loop Speed
Added Short Circuit Protection (with supporting hardware)
Added Analog 3 and 4 Inputs (with supporting hardware)
Added Operating Mode Change on-the-fly
Changeable PWM frequency
Selectable polarity for Dead Man Switch
Modified Flashing Pattern
Separate PID Gains for Ch1 and C2, changeable on-the-fly
Miscellaneous additions and correction
Added Amps Calibration option
January 10, 2007 1.9 Changed Amps Limit Algorithm
Miscellaneous additions and correction
Console Mode in Roborun
March 7, 2005 1.7b Updated Encoder section.
February 1, 2005 1.7 Added Position mode support with Optical Encoder
Miscellaneous additions and corrections
April 17, 2004 1.6 Added Optical Encoder support
March 15, 2004 1.5 Added finer Amps limit settings
Enhanced Roborun utility
August 25, 2003 1.3 Added Closed Loop Speed mode
Added Data Logging support
Removed RC monitoring
August 15, 2003 1.2 Modified to cover AX500 controller design
Changed Power Connection section
April 15, 2003 1.1 Added analog mode section
Added position mode section
Added RCRC monitoring feature
Updated Roborun utility section
Modified RS232 watchdog
March 15, 2003 1.0 Initial Release
The information contained in this manual is believed to be accurate and reliable. However,
it may contain errors that were not noticed at time of publication. User’s are expected to
perform their own product validation and not rely solely on data contained in this manual.
AX500 Motor Controller User’s Manual 3
4 AX500 Motor Controller User’s Manual Version 1.9b. June 1, 2007
Revision History 3
SECTION 1 Important Safety Warnings 11
This product is intended for use with rechargeable batteries 11
Avoid Shorts when Mounting Board against Chassis 11
Do not Connect to a RC Radio with a Battery Attached 11
Beware of Motor Runaway in Improperly Closed Loop 11
SECTION 2 AX500
Quick Start 13
What you will need 13
Locating the Connectors 13
Connecting to the Batteries and Motors 15
Connecting to the 15-pin Connector 16
Connecting the R/C Radio 16
Powering On the Controller 17
Default Controller Configuration 18
Connecting the controller to your PC using Roborun 18
Obtaining the Controller’s Software Revision Number 19
Exploring further 20
SECTION 3 AX500 Motor Controller Overview 21
Product Description 21
Technical features 22
SECTION 4 Connecting Power and Motors to the Controller 25
Power Connections 25
Controller Power 26
Controller Powering Schemes 27
Powering the Controller from a single Battery 27
Powering the Controller Using a Main and Backup Battery 28
Connecting the Motors 28
Single Channel Operation 29
Converting the AX500 to Single Channel 30
Power Fu ses 30
Wire Length Limits 31
Electrical Noise Reduction Techniques 31
Power Regeneration Considerations 31
Overvoltage Protection 32
Undervoltage Protection 32
Using the Controller with a Power Supply 33
AX500 Motor Controller User’s Manual 5
SECTION 5 General Operation 35
Basic Operation 35
Input Command Modes 35
Selecting the Motor Control Modes 36
Open Loop, Separate Speed Control 36
Open Loop, Mixed Speed Control 36
Closed Loop Speed Control 37
Close Loop Position Control 37
User Selected Current Limit Settings 38
Temperature-Based Current Limitation 38
Battery Current vs. Motor Current 39
Programmable Acceleration 40
Command Control Curves 42
Left / Right Tuning Adjustment 43
Activating Brake Release or Separate Motor Excitation 45
Emergency Stop using External Switch 45
Inverted Operation 45
Special Use of Accessory Digital Inputs 46
Using the Inputs to Activate the Buffered Output 46
Using the Inputs to turn Off/On the Power MOSFET
transistors 46
SECTION 6 Connecting Sensors and Actuators to Input/Outputs 47
AX500 Connections 47
AX500’s Inputs and Outputs 48
I/O List and Pin Assignment 50
Connecting devices to Output C 51
Connecting Switches or Devices to Input E 52
Connecting Switches or Devices to Input F 52
Connecting Switches or Devices to EStop/Invert Input 53
Analog Inputs 54
Connecting Position Potentiometers to Analog Inputs 54
Connecting Tachometer to Analog Inputs 55
Connecting External Thermistor to Analog Inputs 57
Using the Analog Inputs to Monitor External Voltages 58
Connecting User Devices to Analog Inputs 59
Internal Voltage Monitoring Sensors 59
Internal Heatsink Temperature Sensors 59
SECTION 7 Closed Loop Position Mode 63
Mode Description 63
Selecting the Position Mode 63
6 AX500 Motor Controller User’s Manual Version 1.9b. June 1, 2007
Position Sensor Selection 64
Sensor Mounting 64
Feedback Potentiometer wiring 65
Feedback Potentiometer wiring in RC or RS232 Mode 65
Feedback Potentiometer wiring in Analog Mode 65
Analog Feedback on Single Channel Controllers 66
Feedback Wiring in RC or RS232 Mode on Single Channel
Controllers 66
Feedback Wiring in Analog Mode on Single Channel
Controllers 67
Sensor and Motor Polarity 67
Encoder Error Detection and Protection 68
Adding Safety Limit Switches 69
Using Current Limiting as Protection 70
Control Loop Description 70
PID tuning in Position Mode 71
SECTION 8 Closed Loop Speed Mode 73
Mode Description 73
Selecting the Speed Mode 73
Tachometer or Encoder Mounting 74
Tachometer wiring 74
Speed Sensor and Motor Polarity 74
Adjust Offset and Max Speed 75
Control Loop Description 76
PID tuning in Speed Mode 77
SECTION 9 Normal and
Fault Condition LED Messages 79
Diagnostic LED 79
Normal Operation Flashing Pattern 79
Output Off / Fault Condition 80
SECTION 10 R/C Operation 81
Mode Description 81
Selecting the R/C Input Mode 82
Connector I/O Pin Assignment (R/C Mode) 82
R/C Input Circuit Description 83
Supplied Cable Description 83
Powering the Radio from the controller 84
Connecting to a Separately Powered Radio 85
Operating the Controller in R/C mode 86
AX500 Motor Controller User’s Manual 7
Reception Watchdog 87
R/C Transmitter/Receiver Quality Considerations 88
Joystick Deadband Programming 88
Command Control Curves 89
Left/Right Tuning Adjustment 90
Joystick Calibration 90
Data Logging in R/C Mode 91
SECTION 11 Analog Control and Operation 93
Mode Description 93
Connector I/O Pin Assignment (Analog Mode) 94
Connecting to a Voltage Source 95
Connecting a Potentiometer 95
Selecting the Potentiometer Value 96
Analog Deadband Adjustment 97
Power-On S afet y 98
Under Voltage Safety 98
Data Logging in Analog Mode 98
SECTION 12 Serial (RS-232) Controls and Operation 101
Use and benefits of RS232 101
Connector I/O Pin Assignment (RS232 Mode) 102
Cable configuration 103
Extending the RS232 Cable 103
Communication Settings 104
Establishing Manual Communication with a PC 104
Entering RS232 from R/C or Analog mode 105
Data Logging String in R/C or Analog mode 105
RS232 Mode if default 106
Commands Acknowledge and Error Messages 106
Character Echo 106
Command Acknowledgement 106
Command Error 10 6
Watchdog time-out 107
RS-232 Watchdog 107
Controller Commands and Queries 107
Set Motor Command Value 108
Set Accessory Output 108
Query Power Applied to Motors 109
Query Amps from Battery to each Motor Channel 10 9
Query Analog Inputs 110
Query Heatsink Temperatures 110
Query Battery Voltages 111
8 AX500 Motor Controller User’s Manual Version 1.9b. June 1, 2007
Query Digital Inputs 111
Reset Controller 111
Accessing & Changing Configuration Parameter in Flash 112
Apply Parameter Changes 11 2
Flash Configuration Parameters List 113
Input Control Mode 11 4
Motor Control Mode 11 4
Amps Limit 11 5
Acceleration 116
Input Switches Function 11 6
RC Joystick or Analog Deadband 117
Exponentiation on Channel 1 and Channel 2 117
Left/Right Adjust 11 8
Default PID Gains 11 8
Joystick Min, Max and Center Values 119
Reading & Changing Operating Parameters at Runtime 119
Operating Modes Registers 120
Read/Change PID Values 121
PWM Frequency Register 121
Controller Status Register 121
Controller Identification Register 122
Current Amps Limit Registers 122
Automatic Switching from RS232 to RC Mode 125
Analog and R/C Modes Data Logging String Format 126
Data Logging Cables 126
Decimal to Hexadecimal Conversion Table 127
SECTION 13 Using the Roborun Configuration Utility 131
System Requirements 131
Downloading and Installing the Utility 131
Connecting the Controller to the PC 132
Roborun Frame, Tab and Menu Descriptions 133
Getting On-Screen Help 134
Loading, Changing Controller Parameters 134
Control Settings 135
Power Settings 136
Analog or R/C Specific Settings 137
Closed Loop Parameters 138
Running the Motors 138
Logging Data to Disk 141
Connecting a Joystick 142
Using the Console 142
Viewing and Logging Data in Analog and R/C Modes 144
Loading and Saving Profiles to Disk 144
AX500 Motor Controller User’s Manual 9
Operating the AX500 over a Wired or Wireless LAN 144
Updating the Controller’s Software 146
Updating the Encoder Software 146
Creating Customized Object Files 147
SECTION 14 Mechanical Specifications 149
Mechanical Dimensions 149
Mounting Considerations 150
Thermal Considerations 150
Attaching the Controller Directly to a Chassis 151
Precautions to observe 152
Wire Dimensions 153
Weight 153
10 AX500 Motor Controller User’s Manual Version 1.9b. June 1, 2007
SECTION 1 Important Safety
Warnings
Read this Section First
The AX500 is a power electronics device. Serious damage, including fire, may
occur to the unit, motors, wiring and batteries as a result of its misuse. Please
review the User’s Manual for added precautions prior to applying full battery
or full load power.
This product is intended for use with rechargeable batteries
Unless special precautions are taken, damage to the controller and/or power supply
may occur if operated with a power supply alone. See“Power Regeneration Considerations” on page 31 of the Users Manual. Always keep the controller connected
to the Battery.
Avoid Shorts when Mounting Board against Chassis
Use precautions to avoid short circuits when mounting the board against a metallic
chassis with the heat sink on or removed. See “Attaching the Controller Directly to a
Chassis” on page 151.
Do not Connect to a RC Radio with a Battery Attached
Without proper protection, a battery attached to an RC Radio may inject its voltage
directly inside the controller’s sensitive electronics. See
Beware of Motor Runaway in Improperly Closed Loop
Wiring or polarity errors between the feedback device and motor in position or
closed loop position mode may cause the controller to runaway with no possibility
to stop it until power is turned off.
AX500 Motor Controller User’s Manual 11
Important Safety Warnings
12 AX500 Motor Controller User’s Manual Version 1.9b. June 1, 2007
SECTION 2 AX500
Quick Start
This section will give you the basic information needed to quickly install, setup and
run your AX500 controller in a minimal configuration.
What you will need
For a minimal installation, gather the following components:
• One AX500 Controller and its provided cables
• 12V to 24V battery
• One or two brushed DC motors
• One R/C to DB15 connector (provided)
• Miscellaneous wires, connectors, fuses and switch
Locating the Connectors
Take a moment to familiarize yourself with the controller’s connectors.
AX500 Motor Controller User’s Manual 13
AX500 Quick Start
Connector to Receiver/
Controls and sensors
Status LED
FIGURE 1. AX500 Controller Front View
The front side contains the 15-pin connector to the R/C radio, joystick or microcomputer, as
well as connections to optional switches and sensors.
At the back of the controller (shown in the figure below) are located all the that must be
connected to the batteries and the motors.
Note:
Both VMot terminals are
connected to each other
in the board and must be
wired to the same voltage.
Power Must be connected to VCon and
VMot
VMot for the controller
to operate
FIGURE 2. AX500 Controller Rear View
VCon
M2+ M1- M1+ VMotM2- 3 x Gnd
Motor 2 Motor 1
14 AX500 Motor Controller User’s Manual Version 1.9b. June 1, 2007
Connecting to the Batteries and Motors
Connecting to the Batteries and Motors
Connection to the batteries and motors is shown in the figure below and is done by connecting wires to the controller’s terminal strip.
Motor2
Motor1
+
-
-
+
M1-
VMot
M1+
GND
VCon
Controller
GND
Power on/off switch
M2-
M2+
GND
VMot
Fuse
12V to 24V
Motor Battery
Notes:
- The Battery Power connection are doubled in order to provide the maximum current to the controller. If
only one motor is used, only one set of motor power cables needs to be connected.
- Typically, 1 or 2 x 12V batteries are connected in series to reach 12 or 24V respectively.
FIGURE 3. AX500 Electrical Power Wiring Diagram
1- Connect each motor to one of the two M+ and M- terminal pairs. Make sure to respect
the polarity, otherwise the motor(s) may spin in the opposite direction than expected
two of the three Ground terminals2- Connect the VCon terminal (powering the controller’s
internal circuits) through a power switch to the main battery. Connect the VMot terminals
(powering the output drivers) directly and permanently to the positive battery terminal.
VCon may be connected to a separate battery to ensure that the controller stays alive even
as the battery powering the Motors discharges. Motors will turn only if voltage is
present on both VCon and VMot. Refer to the chapter “Connecting Power and Motors to
the Controller” on page 25 for more information about batteries and other connection
options.
The two are connected to each other inside the controller. The same is true for the.
You should wire each pair together as shown in the diagram above.
Important Warning
Do not rely on cutting power to the controller for it to turn off if the Power Control is
left floating. If motors are spinning because the robot is pushed are pushed or
because of inertia, they will act as generators and will turn the controller, possibly in
an unsafe state. Always use the switch on the VCon terminal to power the controller
On or Off.
AX500 Motor Controller User’s Manual 15
AX500 Quick Start
Important Warning
The controller includes large capacitors. When connecting the Motor Power Cables,
a spark will be generated at the connection point. This is a normal occurrence and
should be expected.
Connecting to the 15-pin Connector
The controller’s I/O are located on it’s standard 15-pin D-Sub Connector. The functions of
some pins varies depending on controller model and operating mode. Pin assignment is
found in the table below.
Signal
Pin
1 100mA Digital Output C (same as pin 9)
2TxData
3 RC Ch1 RxData Unused
4 RC Ch 2 Digital Input F
5 Ground Out
6 Unused
7 Unused
8 Digital Input E and Analog Input 4
9 100mA Digital Output C (same as pin 1)
10 Analog Input 2
11 Analog Input 1
12 Analog Input 3
13 Ground Out
14 +5V Out (100mA max.)
15 Emergency Stop or Invert Switch input
RC Mode RS232 Mode Analog Mode
Connecting the R/C Radio
Connect the R/C adapter cables to the controller on one side and to two or three channels
on the R/C receiver on the other side. If present, the third channel is for activating the
accessory outputs and is optional.
When operating the controller in “Separate” mode, the wire labelled Ch1 controls Motor1,
and the wire labelled Ch2 controls Motor2.
When operating the controller in “Mixed” mode, Ch1 is used to set the robot’s speed and
direction, while Ch2 is used for steering.
See “R/C Operation” on page 81 of the User’s Manual for a more complete discussion on
R/C commands, calibration and other options.
16 AX500 Motor Controller User’s Manual Version 1.9b. June 1, 2007
Powering On the Controller
Channel 3
Channel 2
Channel 1
Pin 1
15
FIGURE 4. R/C connector wiring for 3 channels and battery elimination (BEC)
This wiring - with the wire loop uncut - assumes that the R/C radio will be powered by the
AX500 controller. Other wiring options are described in “R/C Operation” on page 81 of the
User’s Manual.
Important Warning
Do not connect a battery to the radio when the wire loop is uncut. The RC battery
voltage will flow directly into the controller and cause permanent damage if its voltage is higher than 5.5V.
3: Channel 1 Command Pulses
4: Channel 2 Command Pulses
6: Radio battery (-) Ground
7: Radio battery (+)
8: Channel 3 Command Pulses
8
9
Wire loop bringing power from
controller to RC radio
Connecting the optional channel 3 will enable you to turn on and off the accessory output.
See “Connecting Sensors and Actuators to Input/Outputs” on page 47 and “Data Logging
in R/C Mode” on page 91 of the User’s Manual.
Powering On the Controller
Important reminder: There is no On-Off switch on the controller. You must insert a switch
on the controller’s power terminal as described in section“Connecting to the Batteries and
Motors” on page 15.
To power the controller, center the joystick and trims on the R/C transmitter. In Analog
mode, center the command potentiomenter or joystick.Then turn on the switch that you
have placed on the on the VCon wire.
AX500 Motor Controller User’s Manual 17
AX500 Quick Start
The status LED will start flashing a pattern to indicate the mode in which the controller is
in:
FIGURE 5. Status LED Flashing pattern during normal operation
Default Controller Configuration
Version 1.9b of the AX500 software is configured with the factory defaults shown in the
table below. Although Roboteq strives to keep the same parameters and values from one
version to the next, changes may occur from one revision to the next. Make sure that you
have the matching manual and software versions. These may be retrieved from the
Roboteq web site.
TABLE 1. AX500 Default Settings
RC Mode
RS232 Mode No Watchdog
RS232 Mode with Watchdog
Analog Mode
Parameter Default Values Letter
Input Command mode: (0) = R/C Radio mode I
Motor Control mode (0) = Separate A, B, speed control, open loop C
Amp limit (5) = 13.125A A
Acceleration (2) = medium-slow S
Input switch function (3) = no action U
Joystick Deadband (2) = 16% d
Exponentiation on channel 1 (0) = Linear (no exponentiation) E
Exponentiation on channel 2 (0) = Linear (no exponentiation) F
Left / Right Adjust (7) = no adjustment L
Any one of the parameters listed in Table 1, and others not listed, can easily be changed
either using the PC with the Roboteq Configuration Utility. See “Using the Roborun Configuration Utility” on page 131.
Connecting the controller to your PC using Roborun
Connecting the controller to your PC is not necessary for basic R/C operation. However, it
is a very simple procedure that is useful for the following purposes:
• to Read and Set the programmable parameters with a user-friendly graphical inter-
face
• to obtain the controller’s software revision and date
• to send precise commands to the motors
• to read and plot real-time current consumption value
• Save captured parameters onto disk for later analysis
18 AX500 Motor Controller User’s Manual Version 1.9b. June 1, 2007
Obtaining the Controller’s Software Revision Number
• to update the controller’s software
FIGURE 6. Roborun Utility screen layout
To connect the controller to your PC, use the provided cable. Connect the 15-pin connector
to the controller. Connect the 9-pin connector to your PC’s available port (typically COM1) -
use a USB to serial adapter if needed. Apply power to the controller to turn it on.
Load your CD or download the latest revision of Roborun software from
www.Roboteq.com, install it on your PC and launch the program. The software will automatically establish communication with the controller, retrieve the software revision number and present a series of buttons and tabs to enable its various possibilities.
The intuitive Graphical User Interface will let you view and change any of the controller’s
parameters. The “Run” tab will present a number of buttons, dials and charts that are used
for operating and monitoring the motors.
Obtaining the Controller’s Software Revision Number
One of the unique features of the AX500 is the ability to easily update the controller’s oper-
ating software with new revisions downloaded from Roboteq’s web site at
www.roboteq.com. This is useful for adding features and/or improving existing ones.
AX500 Motor Controller User’s Manual 19
AX500 Quick Start
Exploring further
Each software version is identified with a unique number. Obtaining this number can be
done using the PC connection discussed previously.
Now that you know your controller’s software version number, you will be able to see if a
new version is available for download and installation from Roboteq’s web site and which
features have been added or improved.
Installing new software is a simple and secure procedure, fully described in “Updating the
Controller’s Software” on page 146 of the User’s Manual.
By following this quick-start section, you should have managed to get your controller to
operate in its basic modes within minutes of unpacking.
Each of the features mentioned thus far has numerous options which are discussed further
in the complete User’s Manual, including:
• Self test mode
• Emergency stop condition
• Using Inputs/Outputs
• Current limiting
• Closed Loop Operation
• Software updating
• and much more
20 AX500 Motor Controller User’s Manual Version 1.9b. June 1, 2007
SECTION 3 AX500 Motor
Controller
Overview
Congratulations! By selecting Roboteq’s AX500 you have empowered yourself with
the industry’s most versatile, and programmable DC Motor Controller for mobile
robots. This manual will guide you step by step through its many possibilities.
Product Description
The AX500 is a highly configurable, microcomputer-based, dual-channel digital
speed or position controller with built-in high power drivers. The controller is
designed to interface directly to high power DC motors in computer controlled or
remote controlled mobile robotics and automated vehicle applications.
The AX500 controller can accept speed or position commands in a variety of ways:
pulse-width based control from a standard Radio Control receiver, Analog Voltage
commands, or RS-232 commands from a microcontroller or wireless modem.
The controller's two channels can be operated independently or can be combined to
set the forward/reverse direction and steering of a vehicle by coordinating the
motion on each side of the vehicle. In the speed control mode, the AX500 can operate in open loop or closed loop. In closed loop operation, actual speed measurements from tachometers are used to verify that the motor is rotating at the desired
speed and direction and to adjust the power to the motors accordingly.
The AX500 can also be configured to operate as a precision, high torque servo controller. When connected to a potentiometer coupled to the motor assembly, the
controller will command the motor to rotate up to a desired angular position.
Depending on the DC motor's power and gear ratio, the AX500 can be used to
move or rotate steering columns or other physical objects with very high torque.
The AX500 is fitted with many safety features ensuring a secure power-on start,
automatic stop in case of command loss, over current protection on both channels,
and overheat protection.
The motors are driven using high-efficiency Power MOSFET transistors controlled
using Pulse Width Modulation (PWM) at 16kHz. The AX500 power stages can oper-
AX500 Motor Controller User’s Manual 21
AX500 Motor Controller Overview
ate from 12 to 24VDC and can sustain up to 15A of controlled current, delivering up to
360W (approximately 0.5 HP) of useful power to each motor.
The many programmable options of the AX500 are easily configured using the supplied PC
utility. Once programmed, the configuration data are stored in the controller's non-volatile
memory, eliminating the need for cumbersome and unreliable jumpers.
Technical features
Fully Digital, Microcontroller-based Design
• Multiple operating modes
• Fully programmable through connection to a PC
• Non-volatile storage of user configurable settings
• Simple operation
• Software upgradable with new features
Multiple Command Modes
• Radio-Control Pulse-Width input
• Serial port (RS-232) input
• 0-5V Analog Command input
Multiple Advanced Motor Control Modes
• Independent operation on each channel
• Mixed control (sum and difference) for tank-like steering
• Open Loop or Closed Loop Speed mode
• Position control mode for building high power position servos
• Modes selectable independently for each channel
Automatic Joystick Command Corrections
• Joystick min, max and center calibration
• Selectable deadband width
• Selectable exponentiation factors for each joystick
• 3rd R/C channel input for accessory output activation
Special Function Inputs/Outputs
• 2 Analog inputs. Used as:
• Tachometer inputs for closed loop speed control
• Potentiometer input for position (servo mode)
• Motor temperature sensor inputs
• External voltage sensors
• User defined purpose (RS232 mode only)
• 2 Extra analog inputs. Used as:
• Potentiometer input for position while in analog command mode
22 AX500 Motor Controller User’s Manual Version 1.9b. June 1, 2007
Technical features
• User defined purpose (RS232 mode only)
• One Switch input configurable as
• Emergency stop command
• Reversing commands when running vehicle inverted
• General purpose digital input
• One general purpose 12V, 100mA output for accessories
• Up to 2 general purpose digital inputs
Internal Sensors
• Voltage sensor for monitoring the main 12 to 24V battery system operation
• Voltage monitoring of internal 12V
• Temperature sensors on the heat sink of each power output stage
• Sensor information readable via RS232 port
Low Power Consumption
• Optional backup power input for powering safely the controller if the motor batteries
are discharged
• Max 100mA idle current consumption
• No power consumed by output stage when motors are stopped
• Regulated 5V output for powering R/C radio. Eliminates the need for separate R/C
battery
High Efficiency Motor Power Outputs
• Two independent power output stages
• Optional Single Channel operation at double the current
• Dual H bridge for full forward/reverse operation
• Ultra-efficient 100mOhm ON resistance (RDSon) MOSFET transistors
• 12 to 24V operation
• Terminal strip up to AWG14 wire
• Temperature-based Automatic Current Limitation
• 15A up to 30 seconds
• 10A up to 1 minute
• 8A continuous
• High current operation may be extended with forced cooling
• 60A peak Amps per channel
• 16kHz Pulse Width Modulation (PWM) output
• Auxiliary output for brake, clutch or armature excitation
Advanced Safety Features
• Safe power on mode
• Automatic Power stage off in case of electrically or software induced program fail-
ure
• Overvoltage and Undervoltage protection
• Regeneration current limiting
AX500 Motor Controller User’s Manual 23
AX500 Motor Controller Overview
• Watchdog for automatic motor shutdown in case of command loss (R/C and RS232
modes)
• Diagnostic LED
• Programmable motor acceleration
• Built-in controller overheat sensor
• Emergency Stop input signal and button
Data Logging Capabilities
• 13 internal parameters, including battery voltage, captured R/C command, tempera-
ture and Amps accessible via RS232 port
• Data may be logged in a PC, PDA or microcomputer
• Efficient heat sinking. Operates without a fan in most applications.
• 4.20” (106.7mm) long x 2.90” (73.7mm) wide
• -20o to +85o C heatsink operating environment
• 3.0oz (85g)
24 AX500 Motor Controller User’s Manual Version 1.9b. June 1, 2007
Power Connections
SECTION 4 Connecting
Power and
Motors to the
Controller
This section describes the AX500 Controller’s connections to power sources and motors.
Important Warning
Please follow the instructions in this section very carefully. Any problem due to wiring errors may have very serious consequences and will not be covered by the product’s warranty.
Power Connections
The AX500 has three Ground, two Vmot terminals and a Vcon terminal. The power terminals are located at the back end of the controller. The various power terminals are identified
by markings on the PCB.The power connections to the batteries and motors are shown in
the figure below.
AX500 Motor Controller User’s Manual 25
Connecting Power and Motors to the Controller
Note:
Both VMot terminals are
connected to each other in
the board and must be
wired to the same voltage.
VMot
M2+ M1- M1+ VMotM2- 3 x Gnd
Motor 2 Motor 1
FIGURE 7. AX500 Controller Rear View
Controller Power
The AX500 uses a flexible power supply scheme that is best described in Figure 8. In this
diagram, it can be seen that the power for the Controller’s processor is separate from this
of the motor drivers. In typical applications, the VMot is connected in permanence to the
battery while VCon is connected to the battery through a On/Off switch.
VCon
Channel 1 MOSFET Power Stage
Microcomputer &
MOSFET Drivers
Channel 2 MOSFET Power Stage
8V min
30V max
FIGURE 8. Representation of the AX500’s Internal Power Circuits
5Vmin
30V max
5Vmin
30V max
M1-
M1+
Vmot
GND
Vcon
GND
GND
Vmot
M2+
M2-
26 AX500 Motor Controller User’s Manual Version 1.9b. June 1, 2007
Controller Powering Schemes
The table below shows the state of the controller depending on the voltage applied to
Vcon and Vmot.
TABLE 2. Controller status depending on Vcon and Vmot voltage
VCon VMot Controller Status
Off Off Off
Off 5-24V Off
8-24V Off Controller MCU is On. Controller will communicate but motors
cannot be activated
8-24V 5-24V Controller is On and motors are activated
Controller Powering Schemes
Powering the Controller from a single Battery
The diagram on Figure 19 show how to wire the controller to a single battery circuit and
how to turn power On and Off.
Motor2
+
-
-
+
Motor1
M1-
VMot
M1+
GND
VCon
Controller
GND
Notes:
- The Battery Power connection are doubled in order to provide the maximum current to the controller. If
only one motor is used, only one set of motor power cables needs to be connected.
- Typically, 1 or 2 x 12V batteries are connected in series to reach 12 or 24V respectively.
Power on/off switch
M2-
M2+
GND
VMot
Fuse
12V to 24V
Motor Battery
FIGURE 9. AX500 Electrical Power Wiring Diagram
AX500 Motor Controller User’s Manual 27
Connecting Power and Motors to the Controller
Motor2
There is no need to insert a separate switch on Power cables, although for safety reasons,
it is highly recommended that a way of quickly disconnecting the Motor Power be provided
in the case of loss of control and all of the AX500 safety features fail to activate.
Powering the Controller Using a Main and Backup Battery
In typical applications, the main motor batteries will get eventually weaker and the voltage
will drop below the level needed for the internal microcomputer to properly operate. For all
professional applications it is therefore recommended to add a separate 12V (to 24V)
power supply to ensure proper powering of the controller under any conditions. This dual
battery configuration is highly recommended in 12V systems.
+
-
-
+
Motor1
M1-
M1+
VMot
GND
VCon
Controller
GND
GND
FIGURE 10. Powering the AX500 with a Main and Backup Supply
Important Warning
Unless you can ensure a steady 8V to 24V voltage in all conditions, it is recommended that the battery used to power the controller’s electronics be separate from
the one used to power the motors. This is because it is very likely that the motor batteries will be subject to very large current loads which may cause the voltage to
eventually dip below 12V as the batteries’ charge drops. The separate backup power
supply should be connected to the VCon input.
M2-
M2+
VMot
Power on/off
switch
Fuse
12V to 24V
Motor Battery
12V to 24V
Backup Battery
Connecting the Motors
Connecting the motors is simply done by connecting each motor terminal to the M1+
(M2+) and M1- (M2-) terminal. Which motor terminal goes to which of the + or - controller
output is typically determined empirically.
28 AX500 Motor Controller User’s Manual Version 1.9b. June 1, 2007
After connecting the motors, apply a minimal amount of power using the Roborun PC utility with the controller configured in Open Loop speed mode. Verify that the motor spins in
the desired direction. Immediately stop and swap the motor wires if not.
In Closed Loop Speed or Position mode, beware that the motor polarity must match this of
the feedback. If it does not, the motors will runaway with no possibility to stop other than
switching Off the power. The polarity of the Motor or off the feedback device may need to
be changed.
Important Warning
Make sure that your motors have their wires isolated from the motor casing. Some
motors, particularly automotive parts, use only one wire, with the other connected
to the motor’s frame.
If you are using this type of motor, make sure that it is mounted on isolators and that
its casing will not cause a short circuit with other motors and circuits which may
also be inadvertently connected to the same metal chassis.
Single Channel Operation
Single Channel Operation
The AX500’s two channel outputs can be paralleled as shown in the figure below so that
they can drive a single load with twice the power. To perform in this manner, the controller’s Power Transistor that are switching in each channel must be perfectly synchronized.
Without this synchronization, the current will flow from one channel to the other and cause
the destruction of the controller.
The controller may be ordered with the -SC (Single Channel) suffix. This version incorporates a hardware setting inside the controller which ensures that both channels switch in a
synchronized manner and respond to commands sent to channel 1.
Warning:
Use this wiring only with
-SC versions (Single
Channel) of the controller
FIGURE 11. Wiring for Single Channel Operation
+
-
VMot
M1-
M1+
VCon
Controller
GND
GND
GND
M2-
M2+
VMot
Pwr Ctrl
12V to 40V
GND
AX500 Motor Controller User’s Manual 29
Connecting Power and Motors to the Controller
Converting the AX500 to Single Channel
The AX500 can be easily modified into a Single Channel version by placing a jumper on the
PCB. This step must be undertook only if you have the proper tooling and technical skills.
• Disconnect the controller from power
• Place a drop of solder on the PCB jumper pad shown in Figure 12 .
Before paralleling the outputs,
• Place the load on channel 1 and verify that it is activated by commands on channel
1.
• Then place the load on channel 2 and verify that is also activated by commands on
channel 1.
• Commands on channel 2 should have no effects on either output.
It will be safe to wire in parallel the controller’s outputs only after you have verified that
both outputs react identically to channel 1 commands.
Jumper "open"
Single Channel
FIGURE 12. AX500 Solder Jumper setting for Single Channel Operation
Power Fuses
For low Amperage applications (below 30A per motor), it is recommended that a fuse be
inserted in series with the main battery circuit as shown in the Figure 9 on page 27.
The fuse will be shared by the two output stages and therefore must be placed before the
Y connection to the two power wires. Fuse rating should be the sum of the expected current on both channels. Note that automotive fuses are generally slow will be of limited
effectiveness in protecting the controller and may be omitted in high current application.
The fuse will mostly protect the wiring and battery against after the controller has failed.
Place solder ball to
close jumper and
enable single channel
mode
Important Warning
30 AX500 Motor Controller User’s Manual Version 1.9b. June 1, 2007
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