Page 1 AX2550 AX2850 Dual Channel High Power 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.
Page 2 AX2550 Motor Controller User’s Manual Version 1.9b. June 1, 2007...
Page 3: Revision History
Revision History Revision History Date Version June 1, 2007 1.9b January 10, 2007 March 7 , 2005 1.7b February 1, 2005 April 17 , 2004 March 15, 2004 August 25, 2003 August 15, 2003 April 15, 2003 March 15, 2003 The information contained in this manual is believed to be accurate and reliable.
Page 4 AX2550 Motor Controller User’s Manual Version 1.9b. June 1, 2007...
Page 5: Table Of Contents
Revision History 3 SECTION 1 Important Safety Warnings 13 This product is intended for use with rechargeable batteries 13 Do not Connect to a RC Radio with a Battery Attached 13 Beware of Motor Runaway in Improperly Closed Loop 13 SECTION 2 AX2550 Quick Start 15...
Page 6 SECTION 5 SECTION 6 AX2550 Motor Controller User’s Manual General Operation 41 Basic Operation 41 Input Command Modes 41 Selecting the Motor Control Modes 42 Open Loop, Separate Speed Control 42 Open Loop, Mixed Speed Control 42 Closed Loop Speed Control 43 Close Loop Position Control 43 User Selected Current Limit Settings 44 Temperature-Based Current Limitation 44...
Page 7 Using Current Limiting as Protection 93 Control Loop Description 93 PID tuning in Position Mode 94 SECTION 9 Closed Loop Speed Mode 97 Mode Description 97 Selecting the Speed Mode 97 Using Optical Encoder for Speed Feedback (AX2850 only) 98 AX2550 Motor Controller User’s Manual...
Page 8 SECTION 10 SECTION 11 SECTION 12 AX2550 Motor Controller User’s Manual Tachometer or Encoder Mounting 98 Tachometer wiring 98 Speed Sensor and Motor Polarity 99 Adjust Offset and Max Speed 100 Control Loop Description 100 PID tuning in Speed Mode 102 Normal and Fault Condition LED Messages 103 Use of the LED Display 103...
Page 9 Analog Deadband Adjustment 127 Power-On Safety 128 Under Voltage Safety 128 Data Logging in Analog Mode 128 SECTION 13 Serial (RS-232) Controls and Operation 131 Use and benefits of RS232 131 Connector I/O Pin Assignment (RS232 Mode) 132 Cable configuration 133 Extending the RS232 Cable 133 Communication Settings 134 Establishing Manual Communication with a PC 134...
Page 10 SECTION 14 AX2550 Motor Controller User’s Manual Default PID Gains 150 Joystick Min, Max and Center Values 150 Reading & Changing Operating Parameters at Runtime 151 Operating Modes Registers 152 Read/Change PID Values 152 PWM Frequency Register 153 Controller Status Register 153 Controller Identification Register 154 Current Amps Limit Registers 154 RS232 Encoder Command Set 155...
Page 11 SECTION 15 Using the Roborun Configuration Utility 177 System Requirements 177 Downloading and Installing the Utility 177 Connecting the Controller to the PC 178 Roborun Frame, Tab and Menu Descriptions 179 Getting On-Screen Help 180 Loading, Changing Controller Parameters 181 Control Settings 181 Power Settings 182 Analog or R/C Specific Settings 183...
Page 12 AX2550 Motor Controller User’s Manual Version 1.9b. June 1, 2007...
Page 13: Section 1 Important Safety Warnings
Important Safety SECTION 1 Warnings Read this Section First The AX2550 is a high 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.
Page 14 Important Safety Warnings AX2550 Motor Controller User’s Manual Version 1.9b. June 1, 2007...
Page 15: Section 2 Ax2550 Quick Start
Quick Start This section will give you the basic information needed to quickly install, setup and run your AX2550 controller in a minimal configuration. The AX2850 is a version of the AX2550 controller with the addition of Optical Encoder inputs.
Page 16 White FIGURE 2. Rear Controller Layout AX2550 Motor Controller User’s Manual Program Reset Connector to Operating Status Optical Encoders and Program LED (AX2850 only) Display Controller Power Power Control Ground (-) Yellow Black Motor (-) 12 to 40V (+) Ground (-)
Page 17: Connecting To The Batteries And Motors
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 con- necting the set of wires coming out from the back of the controller. Motor2 Motor1 Notes:...
Page 18: Connecting To The 15-Pin Connector
AX2550 Quick Start the Controller” on page 29 for more information about batteries and other connection options. 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.
Page 19: Connecting The R/C Radio
Connecting the R/C Radio 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.
Page 20: Powering On The Controller
AX2550 Quick Start 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 wire as described in section“Connecting to the Batteries and Motors” on page 17. 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 Power Control input.
Page 21: Default Controller Configuration
These may be retrieved from the Roboteq web site. See “Configuring the Controller using the Switches” on page 171 of the User Manual for a complete configuration parameter list and their possible values.
Page 22: Connecting The Controller To Your Pc Using Roborun
AX2550 Quick Start Restart Press & hold Prog Program mode entered after 10 seconds Press Prog to select next parameter Press Set to select next value for parameter Press Prog to store change and select next parameter Reset controller to exit Connecting the controller to your PC using Roborun Connecting the controller to your PC is not necessary for basic R/C operation.
Page 23: Obtaining The Controller's Software Revision Number
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 auto- matically establish communication with the controller, retrieve the software revision num- ber and present a series of buttons and tabs to enable its various possibilities.
Page 24: Exploring Further
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”...
Page 25: Product Description
SECTION 3 Controller Overview Congratulations! By selecting Roboteq’s AX2550 you have empowered yourself with the industry’s most versatile, powerful and programmable DC Motor Controller for mobile robots. This manual will guide you step by step through its many possibil- ities.
Page 26: Section 3 Ax2550 Motor Controller Overview
The AX2850 is the AX2550 controller fitted with a dual channel optical encoder input mod- ule. Optical Encoders allow precise motor speed and position measurement and enable advance robotic applications.
Page 27 General purpose digital input • One general purpose 24V, 2A output for accessories • Up to 2 general purpose digital inputs Optical Encoder Inputs (AX2850 only) • Inputs for two Quadrature Optical Encoders • up to 250khz Encoder frequency per channel •...
Page 28 AX2550 Motor Controller Overview Advanced Safety Features Data Logging Capabilities Sturdy and Compact Mechanical Design AX2550 Motor Controller User’s Manual • 12 to 40 V operation • High current 8 AWG cable sets for each power stages • Temperature-based Automatic Current Limitation •...
Page 29: Section 4 Connecting Power And Motors To The Controller
Power Connections Connecting SECTION 4 Power and Motors to the Controller This section describes the AX2550 Controller’s connections to power sources and motors. Important Warning Please follow the instructions in this section very carefully. Any problem due to wir- ing errors may have very serious consequences and will not be covered by the prod- uct’s warranty.
Page 30: Controller Power
Connecting Power and Motors to the Controller Controller Power Power Control Ground (-) Yellow Black (top) Motor (+) Motor (-) 12 to 40V (+) Ground (-) 12 to 40V (+) Motor(+) Motor (-) White Green Black Yellow or Green White Motor 1 Motor 2 FIGURE 8.
Page 31 Controller Power Channel 1 MOSFET Power Stage Microcomputer & MOSFET Drivers Channel 2 MOSFET Power Stage FIGURE 9. Representation of the AX2550’s Internal Power Circuits When powered only via the Power Control input, the controller will turn On but motors will not be able to turn until power is also present on the VMot wires The Power Control input also serves as the Enable signal for the DC/DC converter.
Page 32: Powering The Controller From A Single Battery
Connecting Power and Motors to the Controller TABLE 3. Controller Status depending on Power Control and VMot Power Control input is connected to 10.5V to 40V 10.5V to 40V All 3 ground (-) are connected to each other inside the controller. The two main battery wires are also connected to each other internally.
Page 33: Powering The Controller Using A Main And Backup Battery
Controller Powering Schemes 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 AX2550 safety features fail to activate. The two red wires are connected to each other inside the controller.
Page 34: Connecting The Motors
Connecting Power and Motors to the Controller FIGURE 11. Powering the AX2550 with a Main and Backup Supply Important Warning Unless you can ensure a steady 12V to 40V voltage in all conditions, it is recom- mended that the battery used to power the controller’s electronics be separate from the one used to power the motors.
Page 35: Converting The Ax2550 To Single Channel
Single Channel Operation 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 The AX2550’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.
Page 36: Power Fuses
Connecting Power and Motors to the Controller 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. FIGURE 13. Solder Jumper setting for Single Channel Operation FIGURE 14.
Page 37: Electrical Noise Reduction Techniques
Wire Length Limits during acceleration and braking. However, it also means that the fuse may not be able to protect the controller. Wire Length Limits The AX2550 regulates the output power by switching the power to the motors On and Off at high frequencies.
Page 38: Undervoltage Protection
Figure 10 on page 32. Please download the Application Note “Understanding Regeneration” from the www.roboteq.com for an in-depth discussion of this complex but important topic. Important Warning Use the AX2550 only with a rechargeable battery as supply to the Motor Power wires (thick black and red wires).
Page 39: Using The Controller With A Power Supply
Using the Controller with a Power Supply backup voltage drop below 12.V, the DC/DC converter’s output will be approximately 0.5V lower than the highest input. Using the Controller with a Power Supply Using a transformer or a switching power supply is possible but requires special care, as the current will want to flow back from the motors to the power supply during regenera- tion.
Page 40 Connecting Power and Motors to the Controller AX2550 Motor Controller User’s Manual Version 1.9b. June 1, 2007...
Page 41: Section 5 General Operation
Basic Operation General SECTION 5 Operation This section discusses the controller’s normal operation in all its supported operating modes. Basic Operation The AX2550’s operation can be summarized as follows: • Receive commands from a radio receiver, joystick or a microcomputer •...
Page 42: Selecting The Motor Control Modes
General Operation Selecting the Motor Control Modes For each motor, the AX2550 supports multiple motion control modes. The controller’s fac- tory default mode is Open Loop Speed control for each motor. The mode can be changed using any of the methods described in “Programming using built-in Switches and Display” on page 171 and “Loading, Changing Controller Parameters”...
Page 43: Close Loop Position Control
Closed Loop Speed Control In this mode, illustrated in Figure 18, an analog tachometer or an optical encoder (AX2850 only) is used to measure the actual motor speed. If the speed changes because of changes in load, the controller automatically compensates the power output. This mode is preferred in precision motor control and autonomous robotic applications.
Page 44: Temperature-Based Current Limitation
General Operation FIGURE 18. Motor with potentiometer assembly for Position operation User Selected Current Limit Settings The AX2550 has current sensors at each of its two output stages. Every 16 ms, this cur- rent is measured and a correction to the output power level is applied if higher than the user preset value.
Page 45: Battery Current Vs. Motor Current
Battery Current vs. Motor Current When the measured temperature reaches 80oC, the controller’s maximum current limit begins to drop to reach 0A at 100oC. Above 100oC, the controller’s power stage turns itself off completely. TABLE 5. Effect of Case temperature on Max Amps Limit Temperature Below 80 oC 80 oC...
Page 46: Regeneration Current Limiting
General Operation FIGURE 19. Current flow during operation FIGURE 20. Instant and average current waveforms The relation between Battery Current and Motor current is given in the formula below: Example: If the controller reports 10A of battery current while at 10% PWM, the current in the motor is 10 / 0.1 = 100A.
Page 47: Programmable Acceleration
Programmable Acceleration Programmable Acceleration When changing speed command, the AX2550 will go from the present speed to the desired one at a user selectable acceleration. This feature is necessary in order to minimize the surge current and mechanical stress during abrupt speed changes. This parameter can be changed by using the controller’s front switches or using serial com- mands.
Page 48: Command Control Curves
General Operation TABLE 6. Acceleration setting table Acceleration Setting Using RS232 15 Hex 05 Hex When configuring the acceleration parameter using the Roborun utility, four additional acceleration steps can be selected between the six ones selectable using the switch, extending the slowest acceleration to 2.04 seconds from 0 to max speed. See “Power Set- tings”...
Page 49: Left / Right Tuning Adjustment
Left / Right Tuning Adjustment FIGURE 21. Exponentiation curves The AX2550 is delivered with the “linear” curves selected for both joystick channels. To select different curves, the user will need to change the values of “E” (channel 1) and “F” (channel 2) according to the table below.
Page 50 General Operation is found on all R/C transmitters, and which is actually an offset correction, the Left/Right Adjustment is a true multiplication factor as shown in Figure 22 FIGURE 22. Left Right adjustment curves The curves on the left show how a given forward direction command value will cause the motor to spin 3 or 5.25% slower than the same command value applied in the reverse direction.
Page 51: Activating Brake Release Or Separate Motor Excitation
Activating Brake Release or Separate Motor Excitation TABLE 8. Left/Right Adjustment Parameter selection Parameter Value Speed Adjustment -1.5% -0.75% Activating Brake Release or Separate Motor Excitation The controller may be configured so that the Output C will turn On whenever one of the two motors is running.
Page 52: Using The Inputs To Turn Off/On The Power Mosfet Transistors
General Operation The switch connection is described in “Connecting Switches or Devices to EStop/Invert Input” on page 62. The switch must be such that it is in the open state in the normal situa- tion and closed to signal an emergency stop command. After and Emergency Stop condition, the controller must be reset or powered Off and On to resume normal operation.
Page 53: Self-Test Mode
Self-Test Mode When the input is pulled high, all the power MOSFETs are turned Off so that the motors are effectively disconnected from the controller. This function is typically used to create a “dead man switch” when the controller is driven using an analog joystick.
Page 54 General Operation • Encoder Speed or Position if module is installed The entire string is repeated every 208 or 224 milliseconds (depending whether the encoder module is present) with the latest internal parameter values. This information can be logged using the Roborun Utility (see “Viewing and Logging Data in Analog and R/C Modes”...
Page 55: Section 6 Connecting Sensors And Actuators To Input/Outputs
AX2550 Connections Connecting SECTION 6 Sensors and Actuators to Input/Outputs This section describes the various inputs and outputs and provides guidance on how to connect sensors, actuators or other accessories to them. AX2550 Connections The AX2550 uses a set of power wires (located on the back of the unit) and a DB15 con- nector for all necessary connections.
Page 56 Connecting Sensors and Actuators to Input/Outputs DC Motors Optional sensors: - Tachometers (Closed loop Speed mode) - Potentiometers (Servo mode) - Optical Encoder (AX2850 only - all closed loop modes) Motor Power supply wires Power Control wire FIGURE 26. Typical controller connections AX2550 Motor Controller User’s Manual...
Page 57: Ax2550'S Inputs And Outputs
AX2550’s Inputs and Outputs AX2550’s Inputs and Outputs In addition to the RS232 and R/C channel communication lines, the AX2550 includes sev- eral inputs and outputs for various sensors and actuators. Depending on the selected oper- ating mode, some of these I/Os provide feedback and/or safety information to the controller.
Page 58: I/O List And Pin Assignment
Connecting Sensors and Actuators to Input/Outputs I/O List and Pin Assignment The figure and table below lists all the inputs and outputs that are available on the AX2550. FIGURE 27 . Controller’s DB15 connector pin numbering TABLE 10. DB15 connector pin assignment Input or Number Output...
Page 59: Connecting Devices To Output C
AX2550 Motor Controller User’s Manual Description Optocoupler +5V Input. Connect to pin 14** Unused in RevB Hardware R/C radio Channel 3 pulses - (Not available on AX2850) Accessory input E Dead man Switch Input Activate Output C Analog Input 4 in RevB Hardware...
Page 60: Connecting Switches Or Devices To Input E
Connecting Sensors and Actuators to Input/Outputs 5 to FIGURE 28. Connecting inductive and resistive loads to Output C This output can be turned On and Off using the Channel 3 Joystick when in the R/C mode. See “Activating the Accessory Outputs” on page 120 for more information. When the controller is used in RS232 mode, this output can be turned On and Off using the !C (On) and !c (Off) command strings.
Page 61: Connecting Switches Or Devices To Input F
00 to indicate an Off state, or 01 to indicate an On state. This input is not available on the AX2850 or on the AX2550 with the Encoder Module installed. Remember that, in RevB hardware, InputE is shared with the Analog Input 4. If an analog sensor is connected, the controller will return a Digital value of 0 if the voltage is lower than 0.5V and a value of 1 if higher...
Page 62: Connecting Switches Or Devices To Estop/Invert Input
Connecting Sensors and Actuators to Input/Outputs On controllers prior to RevB, Input F is an opto-coupled input and requires the buffer to be powered with a connection between pin 14 and 7 , and between 13 and 6, to operate.This power connection in not needed on RevB hardware.
Page 63: Connecting Position Potentiometers To Analog Inputs
Analog Inputs FIGURE 31. Emergency Stop / Invert switch wiring The status of the EStop/Inv can be read at all times in the RS232 mode with the ?i com- mand string. The controller will respond with three sets of 2 digit numbers. The status of the ES/Inv Input is contained in the last set of numbers and may be 00 to indicate an Off state, or 01 to indicate an On state.
Page 64: Connecting Tachometer To Analog Inputs
Connecting Sensors and Actuators to Input/Outputs Connecting the potentiometer to the controller is as simple as shown in the diagram on Figure 33. FIGURE 33. Potentiometer wiring in Position mode The potentiometer must be attached to the motor frame so that its body does not move in relationship with the motor.
Page 65 Connecting Tachometer to Analog Inputs Since the controller only accepts a 0 to 5V positive voltage as its input, the circuit shown in Figure 34 must be used between the controller and the tachometer: a 10kOhm potentiom- eter is used to scale the tachometer output voltage to -2.5V (max reverse speed) and +2.5V (max forward speed).
Page 66: Connecting External Thermistor To Analog Inputs
Connecting Sensors and Actuators to Input/Outputs Connecting External Thermistor to Analog Inputs Using external thermistors, the AX2550 can be made to supervise the motor’s tempera- ture and adjust the power output in case of overheating. Connecting thermistors is done according to the diagram show in Figure 35. The AX2550 is calibrated using a 10kOhm Negative Coefficient Thermistor (NTC) with the temperature/resistance characteristics shown in the table below.
Page 67: Using The Analog Inputs To Monitor External Voltages
Using the Analog Inputs to Monitor External Voltages To read the temperature, use the ?p command to have the controller return the A/D con- verter’s value. The value is a signed 8-bit hexadecimal value. Use the chart data to convert the raw reading into a temperature value.
Page 68: Internal Heatsink Temperature Sensors
Connecting Sensors and Actuators to Input/Outputs FIGURE 38. AX2550 Analog Input equivalent circuit Internal Voltage Monitoring Sensors The AX2550 incorporates voltage sensors that monitor the Main Battery voltage and the Internal 12V supply. This information is used by the controller to protect it against overvolt- age and undervoltage conditions (see “Overvoltage Protection”...
Page 69: Temperature Conversion C Source Code
Temperature Conversion C Source Code FIGURE 39. Analog reading by controller vs. internal heat sink temperature Temperature Conversion C Source Code The code below can be used to convert the analog reading into temperature. It is provided for reference only. Interpolation table is for the internal thermistors. int ValToHSTemp(int AnaValue) // Interpolation table.
Page 70 Connecting Sensors and Actuators to Input/Outputs AX2550 Motor Controller User’s Manual Version 1.9b. June 1, 2007...
Page 71: Section 7 Installing, Connecting And Using The Encoder Module
Connecting and Using the Encoder Module This section describes the Encoder input module that is factory installed inside the AX2850 or that may be added onto the AX2550. Optical Incremental Encoders Overview Optical incremental encoders are a means for capturing speed and travelled distance on a motor.
Page 72: Recommended Encoder Types
Installing, Connecting and Using the Encoder Mod- 1 Pulse = 4 Transitions = 4 Counts FIGURE 40. Quadrature encoder output waveform The figure below shows the typical construction of a quadrature encoder. As the disk rotates in front of the stationary mask, it shutters light from the LED. The light that passes through the mask is received by the photo detectors.
Page 73: Installing The Encoder Module
The Encoder module is available in kit form for installation by the user inside the AX2550 controller. It may also be ordered factory-installed in the controller by using the product ref- erence AX2850. FIGURE 42. Encoder Module for AX2550. Factory installed in AX2850 AX2550 Motor Controller User’s Manual...
Page 74 Installing, Connecting and Using the Encoder Mod- Follow these simple steps to install: 1- With the power removed, remove the controller’s face plate and slide off the cover. 2- Carefully insert the encoder module on top of the two headers present on the control- ler’s main board and shown in Figure 43.
Page 75: Connecting The Encoder
Connecting the Encoder FIGURE 45. Solder wire for robust assembly 4- Slide the cover back on. Install the new face plate. Connecting the Encoder The Encoder module uses a widely available 8-pin RJ45 connector identical to those found on all Ethernet devices. The connector provides 5V power to the encoders and has inputs for the two quadrature signals from each encoder.
Page 76: Voltage Levels, Thresholds And Limit Switches
Installing, Connecting and Using the Encoder Mod- Cable Length and Noise Considerations Cable should not exceed one 3’ (one meter) to avoid electrical noise to be captured by the wiring. A ferrite core filter must be used for length beyond 2’ (60 cm). For longer cable length use an oscilloscope to verify signal integrity on each of the pulse channels and on the power supply.
Page 77 Voltage Levels, Thresholds and Limit Switches On the 2850 family of controllers, the threshold voltage may be changed under software control to any value between 0 and 5V in order to meet unusual encoder specifications. By default, the threshold level is 2.5V. Another set of comparators on the same input signals detects pulses that are above and below a fixed 0.5V threshold.
Page 78: Wiring Optional Limit Switches
Installing, Connecting and Using the Encoder Mod- Important Warning When a limit switch is activated, the encoder signal that is shared with the switch is no longer visible by the encoder module, and pulse counting and speed measure- ment stops. Wiring Optional Limit Switches If limit switches are needed by the application, additional circuitry is required in order to create a multi-level signal that shares the encoder and the switch information.
Page 79: Wiring Limit Switches Without Encoders
Wiring Limit Switches Without Encoders Wiring Limit Switches Without Encoders If no encoder is used, the Encoder Module’s inputs can be used to wire limit switches directly with solely a pull-up resistor as shown in the diagram below. FIGURE 51. Signals seen by encoder using multi-levels and limit switches Effect of Limit Switches Each pair of limit switches will stop the motion of a given motor in a given direction.
Page 80: Using The Encoder Module To Measure Distance
Installing, Connecting and Using the Encoder Mod- TABLE 16. Effects of Limit Switches 3 and 4 on Motor 2 In Single Channel Mode, limit switches 3 and 4 are used. This is to allow direct connection of an encoder on the inputs for channel 1 and direct connection of switches on the inputs for channel 2 TABLE 17 .
Page 81: Using The Encoder To Track Position
Using the Encoder to Track Position A simple procedure is included in the Roborun PC utility to easily determine and set these parameters. For information, the exact formula is shown below: Measured Speed Value = RPM * PPR * 4 * (Time Base+1) * 256 / (60 * 1000000) or Measured Speed Value = RPM * PPR * (Time Base + 1) / 58593.75 Example: a motor spinning at 1,000 RPM, with an encoder with 200 Pulses per Revolution, and a Time Base set at 4 will produce the following measurement:...
Page 82: Rs232 Communication With The Encoder Module
Installing, Connecting and Using the Encoder Mod- The actual formula is as follows: Where: divider is a configurable parameter of value 1, 2, 4, 8, 16, 32, 64 or 127 If computed distance is less than -127 , then reported distance is -127 If computed distance is larger than +127 , then reported distance is +127 FIGURE 52.
Page 83: Encoder Testing And Setting Using The Pc Utility
Encoder Testing and Setting Using the PC Utility Encoder Testing and Setting Using the PC Utility Extensive diagnostic, calibration, setting and testing support is provided in the Roborun PC utility. Basic instructions on how to install and run the PC utility can be found in “Encoder Setting and Testing”...
Page 84 Installing, Connecting and Using the Encoder Mod- AX2550 Motor Controller User’s Manual Version 1.9b. June 1, 2007...
Page 85: Section 8 Closed Loop Position Mode
Mode Description Closed Loop SECTION 8 Position Mode This section describes the AX2550 Position mode, how to wire the motor and position sen- sor assembly and how to tune and operate the controller in this mode. Mode Description In this mode, the axle of a geared-down motor is coupled to a position sensor that is used to compare the angular position of the axle versus a desired position.
Page 86: Position Sensor Selection
Closed Loop Position Mode Position Sensor Selection The AX2550 may be used with the following kind of sensors: The first two are used to generate an analog voltage ranging from 0V to 5V depending on their position. They will report an absolute position information at all times. Optical encoders report incremental changes from a reference which is their initial position when the controller is powered up or reset.
Page 87: Feedback Potentiometer Wiring In Rc Or Rs232 Mode
Feedback Potentiometer wiring The mechanical coupling between the motor and the sensor must be as tight as possible. If the gear box is loose, the positioning will not be accurate and will be unstable, potentially causing the motor to oscillate. Some sensor, such as potentiometers, have a limited rotation range of typically 270 degrees (3/4 of a turn), which will in turn limit the mechanical motion of the motor/potenti- ometer assembly.
Page 88: Feedback Potentiometer Wiring In Analog Mode
Closed Loop Position Mode FIGURE 55. Pot wiring for RS232 or RC Command and Analog Feedback Feedback Potentiometer wiring in Analog Mode When the controller is configured in Analog mode, the analog inputs 1 and 2 are used for commands while the analog inputs 3 and 4 are used for feedback. Analog inputs 3 and 4 have different characteristics than inputs 1 and 2, and so require a lower resistance poten- tiometer in order to guarantee accuracy Note that the analog inputs 3 and 4 are only available on the AX2550 with PCB revision 6.1...
Page 89: Feedback Wiring In Rc Or Rs232 Mode On Single Channel Controllers
Analog Feedback on Single Channel Controllers Analog Feedback on Single Channel Controllers On Single Channel controllers (SC Version - not to be confused with Dual Channel control- lers of which only one channel is used for position control - See “Single Channel Opera- tion”...
Page 90: Using Optical Encoders In Position Mode
Closed Loop Position Mode This wiring is also the one to use when the controller is in Analog mode but switched to RS232 after reset using the method discussed in “Entering RS232 from R/C or Analog mode” on page 136 Using Optical Encoders in Position Mode The AX2550 and AX1500 may be equipped with an optional Optical Encoder Module.
Page 91: Encoder Error Detection And Protection
Encoder Error Detection and Protection 9. If the motor turns in the direction in which the sensor was moved, the polarity is correct. The sensor axle may be tighten to the motor assembly. 10. If the motor turns in the direction away from the sensor, then the polarity is reversed.
Page 92 Closed Loop Position Mode The diode polarity depends on the particular wiring and motor orientation used in the appli- cation. If the diode is mounted backwards, the motor will not stop once the limit switch lever is pressed. If this is the case, reverse the diode polarity. The diodes may be eliminated, but then it will not be possible for the controller to move the motor once either of the limit switches has been triggered.
Page 93: Control Loop Description
Using Current Limiting as Protection Manual Emergency Stop Switch FIGURE 60. Safety limit using AX2550’s Emergency Stop input Important Warning Limit switches must be used when operating the controller in Position Mode. This will significantly reduce the risk of mechanical damage and/or injury in case of dam- age to the position sensor or sensor wiring.
Page 94: Pid Tuning In Position Mode
Closed Loop Position Mode A higher Proportional Gain will cause the algorithm to apply a higher level of power for a given measured error, thus making the motor move quicker. Because of inertia, however, a faster moving motor will have more difficulty stopping when it reaches its desired position. It will therefore overshoot and possibly oscillate around that end position.
Page 95 PID tuning in Position Mode The Roborun PC utility makes this experimentation easy by providing one screen for chang- ing the Proportional, Integral and Differential gains and another screen for running and monitoring the motors. When tuning the motor, first start with the Integral Gain at zero, increasing the Proportional Gain until the motor overshoots and oscillates.
Page 96 Closed Loop Position Mode AX2550 Motor Controller User’s Manual Version 1.9b. June 1, 2007...
Page 97: Section 9 Closed Loop Speed Mode
Mode Description Closed Loop SECTION 9 Speed Mode This section discusses the AX2550 Close Loop Speed mode. Mode Description In this mode, an analog or digital speed sensor measures the actual motor speed and com- pares it to the desired speed. If the speed changes because of changes in load, the control- ler automatically compensates the power output.
Page 98: Using Optical Encoder For Speed Feedback (Ax2850 Only)
Closed Loop Speed Mode Using Optical Encoder for Speed Feedback (AX2850 only) Digital Optical Encoders may be used to capture accurate motor speed. This capability is only available on controllers fitted with the optional encoder module. Detailed information on how to install and wire optical encoders is provided at “Installing, Connecting and Using the Encoder Module”...
Page 99: Speed Sensor And Motor Polarity
Speed Sensor and Motor Polarity Connecting the tachometer to the controller is as simple as shown in the diagram below. 1kOhm Zero Adjust 100 Ohm pot 1kOhm FIGURE 63. Tachometer wiring diagram Speed Sensor and Motor Polarity The tachometer or encoder polarity (i.e. which rotation direction produces a positive of negative speed information) is related to the motor’s rotation speed and the direction the motor turns when power is applied to it.
Page 100: Adjust Offset And Max Speed
Closed Loop Speed Mode Adjust Offset and Max Speed For proper operation, the controller must see a 0 analog speed value (2.5V voltage on the analog input). To adjust the 0 value when the motors are stopped, use the Roborun utility to view the analog input value while the tachometer is not turning.
Page 101 Control Loop Description ence measured between the desired speed (set by the user) and the actual position (cap- tured by the tachometer). Figure 64 shows a representation of the PID algorithm. Every 16 milliseconds, the control- ler measures the actual motor speed and subtracts it from the desired position to compute the speed error.
Page 102: Pid Tuning In Speed Mode
Closed Loop Speed Mode PID tuning in Speed Mode As discussed above, three parameters - Proportional Gain, Integral Gain, and Differential Gain - can be adjusted to tune the Closed Loop Speed control algorithm. The ultimate goal in a well tuned PID is a motor that reaches the desired speed quickly without overshoot or oscillation.
Page 103: Fault Condition Led Messages
Use of the LED Display Normal and SECTION 10 Fault Condition LED Messages This section discusses the meaning of the various messages and codes that may be dis- played on the LED display during normal operation and fault conditions. Use of the LED Display The AX2550 uses a single 7-segment LED display to report a number of operating or fault conditions.
Page 104: Motor Direction Status
Normal and Fault Condition LED Messages Motor Direction Status When the controller is running, two pairs of LED segments are directly related to com- mand informations to the Power Output stage. The position and meaning of the segments are shown in the figure below. Motor 2 Direction FIGURE 65.
Page 105: Fault Messages
Fault Messages TABLE 18. Motor Commands and resulting display Possible Display Motor 1 Forward Reversed MOSFET Transistors are Motors are freewheeling Rapidly Flashing MOSFET Transistors are Motors are freewheeling Fault Messages The AX2550 uses the LED display to report fault conditions. When these messages are displayed, the motors are normally stopped.
Page 106: Temporary Faults
Normal and Fault Condition LED Messages FIGURE 66. No Radio signal scrolling message Temporary Faults Temporary Faults are condition that cause the controller’s Power Output stage to turn Off and remain off for as long as the fault is present. Temporary Faults are indicated with the LED displaying a solid “8”...
Page 107 Self-Test Display = Software version 1.9b FIGURE 67 . Example of Software revision number display AX2550 Motor Controller User’s Manual...
Page 108 Normal and Fault Condition LED Messages AX2550 Motor Controller User’s Manual Version 1.9b. June 1, 2007...
Page 109: Section 11 R/C Operation
Mode Description R/C Operation SECTION 11 This section describes the controller’s wiring and functions specific to the R/C radio control mode. Mode Description The AX2550 can be directly connected to an R/C receiver. In this mode, the speed or posi- tion information is contained in pulses whose width varies proportionally with the joysticks’...
Page 110: Connector I/O Pin Assignment (R/C Mode)
R/C Operation Selecting the R/C Input Mode The R/C Input Mode is the factory default setting. If the controller has been previously set to a different Input Mode, it will be necessary to reset it to the R/C mode using one of the following methods: Connector I/O Pin Assignment (R/C Mode) FIGURE 69.
Page 111: R/C Input Circuit Description
R/C Input Circuit Description TABLE 19. Connector pin-out in R/C mode Input or Number Output Signal Digital In R/C: Ch 3 / Ana In 4 Analog in Ana in 2 Analog in Ana in 1 Analog in Ana in 3 Power Out Input Input EStop/Inv...
Page 112: Powering The Radio From The Controller
R/C Operation FIGURE 71. RC Cable wiring diagram FIGURE 72. RC connection cable Powering the Radio from the controller The 5V power and ground signals that are available on the controller’s connector may be used to power the R/C radio. The wire loop is used to bring the controller’s power to the the radio as well as for powering the optocoupler stage.
Page 113: Important Warning
Powering the Radio from the controller Channel 2 Channel 1 FIGURE 73. Wiring for powering R/C radio from controller R/C Radio Power R/C Radio FIGURE 74. R/C Radio powered by controller electrical diagram Important Warning Do not connect a battery to the radio when in this mode. The battery voltage will flow directly into the controller and cause permanent damage if its voltage is higher than 5.5V.
Page 114: Connecting To A Separately Powered Radio
R/C Operation Connecting to a Separately Powered Radio This wiring option must be used when the controller is used with a RC receiver that is powered by its own separate battery. The red wire in the loop must be cut so that the 5V out from the controller does not flow to the radio, and so that the battery that is connected to the controller does not inject power into the controller.
Page 115: Reception Watchdog
Reception Watchdog ond indicates the minimum joystick position and 2.0 milliseconds indicates the maximum joystick position. When the joystick is in the center position, the pulse should be 1.5ms. Note that the real pulse-length to joystick-position numbers that are generated by your R/C radio may be different than the ideal 1.0ms to 2.0ms discussed above.
Page 116: R/C Transmitter/Receiver Quality Considerations
R/C Operation If no pulses are present, the motors are disabled, and the controller’s display will scroll alternatively the letters “no ctrl” as shown in Figure 78 below. FIGURE 78. “No control” message will scroll when no valid radio signal is present After powering on the R/C radio receiver and transmitter, and if the wiring is correct, the controller will start receiving pulses.
Page 117: Joystick Deadband Programming
Joystick Deadband Programming noise is generated. Section “Electrical Noise Reduction Techniques” on page 37 provides a few suggestions for reducing the amount of electrical noise generated in your robot. Joystick Deadband Programming In order to avoid undesired motor activity while the joysticks are centered, the AX2550 supports a programmable deadband feature.
Page 118: Left/Right Tuning Adjustment
R/C Operation FIGURE 79. Effect of deadband on joystick position vs. motor speed Command Control Curves The AX2550 can also be set to translate the joystick motor commands so that the motors respond differently depending on whether the joystick is near the center or near the extremes.
Page 119: Automatic Joystick Calibration
Automatic Joystick Calibration There are two methods for calibrating the joysticks: • The automatic method is the simplest and is based on the controller “learning” the joystick’s parameters using the simple training sequence described below. • The manual method lets you enter actual timing numbers directly in the controllers flash memory using your PC running the Roborun configuration utility.
Page 120: Activating The Accessory Outputs
R/C Operation Notes: If you attempt to calibrate the joysticks while the radio is off or not connected to the con- troller, the calibration data will not change and the previously stored information will con- tinue to be used. If calibration is performed with only one R/C channel connected to the controller, then only the joystick that is active will be calibrated.
Page 121: Data Logging In R/C Mode
Data Logging in R/C Mode Output C FIGURE 81. Using Channel 3 to activate accessory outputs Data Logging in R/C Mode While in R/C Mode, the AX2550 will continuously send a string of characters on the RS232 output line. This string will contain 12 two-digit hexadecimal numbers representing the fol- lowing operating parameters.
Page 122 R/C Operation FIGURE 82. Modified R/C cable with RS232 output for data logging to a PC AX2550 Motor Controller User’s Manual DB9 Female DB15 Male To PC To Controller RX Data RS232 Data Out R/C Ch 1 R/C Ch 2 R/C GND R/C +5V Version 1.9b.
Page 123: Section 12 Analog Control And Operation
Mode Description Analog Control SECTION 12 and Operation This section describes how the motors may be operated using analog voltage commands. Mode Description The AX2550 can be configured to use a 0 to 5V analog voltage, typically produced using a potentiometer, to control each of its two motor channels.
Page 124: Connector I/O Pin Assignment (Analog Mode)
Analog Control and Operation Connector I/O Pin Assignment (Analog Mode) When used in the Analog mode, the pins on the controller’s DB15 connector are mapped as described in the table below TABLE 21. DB15 Connector pin assignment in Analog mode Number Signal Output C...
Page 125: Connecting To A Voltage Source
Connecting to a Voltage Source Connecting to a Voltage Source The analog inputs expect a DC voltage of 0 to 5V which can be sourced by any custom cir- cuitry (potentiometer, Digital to Analog converter). The controller considers 2.5V to be the zero position (Motor Off). 0V is the maximum reverse command and +5V is the maximum forward command.
Page 126: Selecting The Potentiometer Value
Analog Control and Operation FIGURE 84. Potentiometer connection wiring diagram The controller includes two 47K ohm resistors pulling the input to a mid-voltage point of 2.5V. When configured in the Analog Input mode, this will cause the motors to be at the Off state if the controller is powered with nothing connected to its analog inputs.
Page 127: Analog Deadband Adjustment
Analog Deadband Adjustment 100K or higher potentiometer. Figure 86 shows how the output voltage varies at the vari- ous potentiometer positions for three typical potentiometer values. Note that the effect is an exponentiation that will cause the motors to start moving slowly and accelerate faster as the potentiometer reaches either end.
Page 128: Data Logging In Analog Mode
Analog Control and Operation TABLE 22. Analog deadband parameters and their effects Parameter Value 3 (default) Important Notice Some analog joysticks do not cause the potentiometer to reach either extreme. This may cause the analog voltage range to be above 0V and below 5V when the stick is moved to the extreme, and therefore the controller will not be able to deliver full for- ward or reverse power.
Page 129 • Internal 12V voltage • Encoder Speed or Position (AX2850) The entire string is repeated every 213 milliseconds with the latest internal parameter val- ues. This information can be logged using the Roborun Utility (see “Viewing and Logging Data in Analog and R/C Modes” on page 192). It may also be stored in a PDA that can be placed in the mobile robot.
Page 130 Analog Control and Operation AX2550 Motor Controller User’s Manual Version 1.9b. June 1, 2007...
Page 131: Section 13 Serial (Rs-232) Controls And Operation
Use and benefits of RS232 Serial (RS-232) SECTION 13 Controls and Operation This section describes the communication settings and the commands accepted by the AX2550 in the RS232 mode of operations. This information is useful if you plan to write your own controlling software on a PC or microcomputer.
Page 132: Connector I/O Pin Assignment (Rs232 Mode)
Serial (RS-232) Controls and Operation Connector I/O Pin Assignment (RS232 Mode) FIGURE 1. Pin locations on the controller’s 15-pin connector When used in the RS232 mode, the pins on the controller’s DB15 connector are mapped as described in the table below TABLE 23.
Page 133: Extending The Rs232 Cable
Cable configuration Cable configuration The RS232 connection requires the special cabling as described in the figure below. The 9- pin female connector plugs into the PC (or other microcontroller). The 15-pin male connec- tor plugs into the AX2550. It is critical that you do not confuse the connector’s pin numbering. The pin numbers on the drawing are based on viewing the connectors from the front (facing the sockets or pins).
Page 134: Establishing Manual Communication With A Pc
To save time and avoid errors, a hyperterm configuration file is automatically installed in your PC’s Start button menu when the Roboteq’s Roborun utility is installed (See “Down- loading and Installing the Utility” on page 177). The configuration file is set to use the AX2550 Motor Controller User’s Manual...
Page 135: Rs232 Communication With The Encoder Module
In all cases, immediately after reset or power up, the controller will output a short identity message followed by a software revision number and software revision date as follows: Roboteq v1.9b 06/01/07 The letter below the prompt message is a code that provides information on the hardware and can be ignored.
Page 136: Data Logging String In R/C Or Analog Mode
Serial (RS-232) Controls and Operation FIGURE 92. Hyperterm session showing power up messages from both MCUs After this information is sent, the Encoder’s MCU will “listen” for approximately 100ms and will enter the In System Programming mode (ISP) if the letter “Z” is sent to it. While in the ISP mode, new software can be loaded into the Encoder’s MCU via the controller’s main serial port.
Page 137: Commands Acknowledge And Error Messages
Commands Acknowledge and Error Messages RS232 Mode if default If the controller is configured in RS232 mode, it will automatically be in the RS232 mode upon reset or power up. In this case, the “OK” message is sent automatically, indicating that the controller is ready to accept commands through its serial port.
Page 138: Controller Commands And Queries
Serial (RS-232) Controls and Operation RS-232 Watchdog For applications demanding the highest operating safety, the controller may be configured to automatically stop the motors (but otherwise remain fully active) if it fails to receive a character on its RS232 port for more than 1 seconds. The controller will also send a “W”...
Page 139: Set Motor Command Value
Controller Commands and Queries TABLE 24. Controller’s basic Commands and Queries Command Type Description ?m or ?M Query Read Heatsink Temperature ?e or ?E Query Read Battery and Internal Voltage ?i or ?I Query Read Digital Inputs ?k or ?K Query Quick read of Encoder Speed or Position if present Set Motor Command Value...
Page 140: Query Amps From Battery To Each Motor Channel
Serial (RS-232) Controls and Operation Query Power Applied to Motors Description: This query will cause the controller to return the actual amount of power that is being applied to the motors at that time. The number is a hexadecimal number ranging from 0 to +127 (0 to 7F in Hexadecimal).
Page 141: Query Heatsink Temperatures
Figure 39 on page 69 shows this correlation. Sample conversion software code is available from Roboteq upon request. The values are unsigned Hexadecimal numbers ranging from 0 to 255. The lowest read value represents the highest temperature.
Page 142: Query Digital Inputs
Syntax: Reply: Where: Examples: Note: the Input E value is not meaningful on the AX2850 or on the AX2550 with Encoder module and should be discarded. Reset Controller Description: This command allows the controller to be reset in the same manner as if the reset button were pressed.
Page 143: Accessing & Changing Configuration Parameter In Flash
Accessing & Changing Configuration Parameter in Flash Accessing & Changing Configuration Parameter in Flash It is possible to use RS232 commands to examine and change the controller’s parameters stored in Flash. These commands will appear cryptic and difficult to use for manual param- eter setting.
Page 144: Flash Configuration Parameters List
Serial (RS-232) Controls and Operation Reply: Table 25 below lists the complete set of configuration parameters that may be accessed and changed using RS232 commands. Flash Configuration Parameters List TABLE 25. Configuration parameters in Flash Location AX2550 Motor Controller User’s Manual + Success, changed parameters are now active - if error Description...
Page 145: Input Control Mode
Accessing & Changing Configuration Parameter in Flash TABLE 25. Configuration parameters in Flash Location Description Joystick Max 2 LS Amps Calibration Parameter 1 Amps Calibration Parameter 2 These parameters are stored in the controller’s Flash memory and are not intended to be changed at runtime.
Page 146: Amps Limit
Serial (RS-232) Controls and Operation This parameters selects the various open loop and closed loop operating modes as well as the feedback method. Definition Motor Control Mode Reserved Ch1 Feedback type Ch2 Feedback type Amps Limit Address: Access: Effective: This parameter configures the controller’s Amps limit. Note that this limits the amps flow- ing out of the power supply.
Page 147: Input Switches Function
Accessing & Changing Configuration Parameter in Flash Acceleration Address: Access: Read/Write Effective: After Reset or ^FF This parameter configures the rate at which the controller internally changes the command value from the one it was to the one just received. Definition 0 = very slow 1 = slow...
Page 148: Exponentiation On Channel 1 And Channel 2
Serial (RS-232) Controls and Operation Definition Input E Input F RC Joystick or Analog Deadband Address: Access: Effective: This parameter configures the amount of joystick or potentiometer motion can take place around the center position without power being applied to the motors. Definition Values are for Joystick deadband 0 = no deadband...
Page 149: Default Encoder Time Base 1 And 2
Accessing & Changing Configuration Parameter in Flash This parameter configures the transfer curve that is applied the input command. Definition (0) = Linear (no exponentiation - default) 1 = strong exponential 2 = normal exponential 3 = normal logarithmic 4 = strong logarithmic Left/Right Adjust Address: Access:...
Page 150: Default Encoder Distance Divider
Serial (RS-232) Controls and Operation Default Encoder Distance Divider Address: Access: Effective: This parameters is the Encoder’s Distance Divider that is loaded after the controller is reset or powered on. The Encoder Distance Divider can be changed at Runtime using separate commands (see page 152).
Page 151: Reading & Changing Operating Parameters At Runtime
Reading & Changing Operating Parameters at Runtime ^1C - Joystick Max 2 MS ^1D - Joystick Max 2 LS Effective: Instantly These parameters are the Gains values that are loaded after the controller is reset or pow- ered on. These Gains apply to both channels. Gains can be changed at Runtime, and values can be different for each channel using separate commands (see page 152).
Page 152: Operating Modes Registers
Serial (RS-232) Controls and Operation TABLE 26. Runtime R/W Parameters list Location Important Notice: Do not write in the locations marked as Read Only. Doing so my cause Controller malfunction. Operating Modes Registers Address: Access: Effective: Modifying the bits in the Operating Mode registers will change the controller’s operating modes on-the fly.
Page 153: Controller Status Register
Reading & Changing Operating Parameters at Runtime ^86 - I2 ^87 - D2 Access: Read/Write Effective: Instantly The Proportional, Integral and Derivative gain for each channel can be read and changed on- the-fly. This function also provides a mean for setting different PID values for each channel. Actual Gain value is the value contained in the register divided by 8.
Page 154: Controller Identification Register
Serial (RS-232) Controls and Operation TABLE 28. Controller Status Register Definition Controller Identification Register Address: Access: Effective: This register may be used to query the Controller’s model and some of its optional hard- ware configurations. TABLE 29. Controller Identification Register Definition Current Amps Limit Registers Address: Access:...
Page 155: Set/Reset Encoder Counters And Destination Registers
RS232 Encoder Command Set RS232 Encoder Command Set When present, the Encoder module responds to a dedicated set of commands and que- ries. The serial port setting and basic command format is identical to this for all other functions of the controller as described in “Serial (RS-232) Controls and Operation” on page 131. Read Encoder Counter Description: Read the value of the Encoder counter(s).
Page 156: Read Speed
While resetting is a single step command, setting the counters to a non-zero value requires two steps: 1- load a 4 byte buffer (32-bit) with the desired value. 2- Transfer the buffer’s content to the counter(s). Loading the buffer can be done using the commands described in “Read / Modify Encoder Module Registers and Parameters”...
Page 157: Read Encoder Limit Switch Status
RS232 Encoder Command Set Read Distance Description: This query will cause the controller to return the distance between the current position and the value in the destination register. The values are signed Hexadecimal numbers ranging from -127 to +127 . The -127 value represents the relative distance according to the formu- las described in “Using the Encoder to Track Position”...
Page 158: Read / Modify Encoder Module Registers And Parameters
Reply: Where: The relationship between the value of n and the switch status is shown in the table below. Extracting the status of a given switch from this number is easily accomplished in software using masking. TABLE 30. Reported value and switch status relationship n Value Note that the 0 and 1 levels represent a Closed Switch and Open Switch status, respec- tively.
Page 159 RS232 Encoder Command Set Example: Read value of parameter at address hex 84 Controller replies, value is 01 Modify parameter Syntax: *mm nn Reply: + if command was executed successfully - if error Where mm= parameter address nn= new parameter value Examples: *84 03 Store 03 into parameter at address hex 84...
Page 160: Register Description
Encoder Hardware ID code Address: Returns a 4-bit number identifying the encoder module hardware version and the status of two on-board jumpers. For Roboteq use only. Switch Status Address: Returns a 4 bit number (4 least significant bits of the byte), each representing the state of one of the limit switches when installed.
Page 161: Destination Register 1 And 2
Register Description These two registers contain either the measured speed or the measured distance. Whether speed or distance information is returned depends on the settings contained in the Mode register described at. This information is returned using the ?p query (see “Query Analog Inputs”...
Page 162: Encoder Threshold
These two 32-bit (4-bytes) registers are used to store the desired destination when the controller is used in position mode. These registers should always be set using the mailbox mechanism described above. See “Using the Encoder to Track Position” on page 81 for a complete description of the position mode.
Page 163: Encoder Testing And Setting Using The Pc Utility
Counter Read Data Format Counter Read Data Format When receiving a counter read query, the encoder module will output the value of its 32-bit counter. If all 32-bit are sent, this would require 8 ASCII digits to represent the value. A 32-bit counter can store over 2 billion counts in each direction.
Page 164 AX2550 Motor Controller User’s Manual Version 1.9b. June 1, 2007...
Page 165: Automatic Switching From Rs232 To Rc Mode
Automatic Switching from RS232 to RC Mode Automatic Switching from RS232 to RC Mode In many computer controlled applications, it may be useful to allow the controller to switch back to the RC mode. This would typically allow a user to take over the control of a robotic vehicle upon computer problem.
Page 166: Analog And R/C Modes Data Logging String Format
The hexadecimal values and format for each parameter is the same as the response to RS232 queries described in page 138. The Encoder Speed/Position parameter is output only on the AX2850 or the AX2550 with Encoder module. Characters are sent by the controller at the rate of one every 8ms. A complete string is sent in 213ms or 224ms.
Page 167: Decimal To Hexadecimal Conversion Table
Decimal to Hexadecimal Conversion Table logging purposes. This cable has a 15-pin male connector and 3 15-pin connectors. The Front View FIGURE 95. ASCII string sent by the controller while in R/C or Analog mode male connector plugs into the controller. The application cable that would normally plug into the controller may now be plugged into one of the adapter’s female connector 2.
Page 168 TABLE 33. 0 to +127 signed or unsigned decimal to hexadecimal conversion table TABLE 34. +128 to 255 unsigned and -1 to -128 signed decimal to hexadecimal conversion table UDec -128 -127 -126 -125 -124 -123 -122 AX2550 Motor Controller User’s Manual UDec UDec UDec...
Page 169 Decimal to Hexadecimal Conversion Table TABLE 34. +128 to 255 unsigned and -1 to -128 signed decimal to hexadecimal conversion table UDec UDec -121 -120 -119 -118 -117 -116 -115 -114 -113 -112 -111 -110 -109 -108 -107 -106 -105 -104 -103 -102...
Page 170 AX2550 Motor Controller User’s Manual Version 1.9b. June 1, 2007...
Page 171: Section 14 Configuring The Controller Using The Switches
Configuring the SECTION 14 Controller using the Switches The AX2550 Speed Controller can be programmed to operate in many modes using a simple set-up procedure. Two buttons and a 7-segment LED display allow the user to examine and change these settings. Alternatively, the controller may be pro- grammed using a PC connected to the AX2550 controller through the RS232 serial communication port.
Page 172: Entering Programming Mode
Configuring the Controller using the Switches 1- Press and hold for 10 sec- onds while resetting or powering up to enter Pro- gram mode 4- Press once to record value change (if any) and move to next parameter Press and hold Program and Set buttons together for 10 second while resetting or powering on to restore factory defaults FIGURE 96.
Page 173: The Special Case Of Joystick Calibration
Programming using built-in Switches and Display Be careful not to confuse the Set and Program button when entering the Program- ming Mode. Pressing and holding the Set button alone for 10 seconds after reset will cause the controller to enter in self-test mode. This will cause the motors to be turned On and Off according the test sequence described in the Self Test section of this manual.
Page 174: Exiting The Parameter Setting Mode
This manual is for software version 1.9b If the controller has a more current software revision, please download an updated version of this manual from the Roboteq web site at www.Roboteq.com. AX2550 Motor Controller User’s Manual Version 1.9b. June 1, 2007...
Page 175 Programmable Parameters List This table shows only the parameters that can be programmed using the switches and display. Other less commonly used parameters exist and are only accessible and pro- grammable using the Configuration Utility (page 177) or the RS232 commands (page 143). TABLE 35.
Page 176 Configuring the Controller using the Switches TABLE 35. Parameters accessible using the controller’s switches and display Order Letter *The coast function is not implemented in this revision of the software. The controller will only operate in brake mode. ** Values are in hexadecimal numbers where the decimal values 10, 11, 12... 15 are repre- sented with the letters A, B, C...
Page 177: Section 15 Using The Roborun Configuration Utility
Configuration Utility A PC-based Configuration Utility is available, free of charge, from Roboteq. This pro- gram makes configuring and operating the AX2550 much more intuitive by using pull-down menus, buttons and sliders. The utility can also be used to update the controller’s software in the field as described in “Updating the Controller’s Soft-...
Page 178: Connecting The Controller To The Pc
RS232 mode. AX2550 Motor Controller User’s Manual • after the installation is complete, run the program from your Start Menu > Programs > Roboteq • to read the current parameters stored in the controller and display them on the computer •...
Page 179: Roborun Frame, Tab And Menu Descriptions
1- Program Revision Number This is the revision and date of the Roborun utility. It is recommended that you always ver- ify that you have the latest revision of the utility from Roboteq’s web site at www.roboteq.com 2- Controller and Communication Link Information This frame will automatically be updated with an indication that a free communication port was found and opened by the utility.
Page 180: Getting On-Screen Help
Using the Roborun Configuration Utility featuring the additional Analog Inputs 3 and 4 are automatically identified as Rev. B in this area of the screen. 3- Parameter Selection and Setting and Special Functions This is the program’s main frame and includes several types of tabs, each of which has sev- eral buttons, menus and other User Interface objects.
Page 181: Loading, Changing Controller Parameters
Loading, Changing Controller Parameters Loading, Changing Controller Parameters The first set of tabs allows you to view and change the controller’s parameters. These tabs are grouped according to the general type of parameters (Controls, Power Setting, and R/C Settings). When starting Roborun, this screen is filled with the default values. If the controller is con- nected to your PC, Roborun will automatically detect it and ask you if you wish to read its settings.
Page 182: Power Settings
Using the Roborun Configuration Utility This pull down menu is used to choose whether the controller will operate in Separate or Mixed mode. For more information on these modes, see “Selecting the Motor Control Modes” on page 42. 3- Input Command Adjustment These pull down menus will let you select one of five conversion curves on each of the input command values.
Page 183: Analog Or R/C Specific Settings
Loading, Changing Controller Parameters 2- Left/Right Adjust This slider will let you configure the controller so that it applies more power to the motors in one direction than in the other. See “Left / Right Tuning Adjustment” on page 49. 3- Acceleration Setting This slider will let you select one of seven preset acceleration values.
Page 184: Encoder Setting And Testing
Using the Roborun Configuration Utility These fields are enabled only if the R/C mode is selected. These number areas will let you read and modify the R/C pulse timing information used by the controller. New values can be entered manually to create different capture characteristics. They are also useful for viewing the stored values after an automatic joystick calibration sequence.
Page 185: Encoder Module Parameters Setting
Encoder Setting and Testing FIGURE 104. Encoder setup and test screen on Roborun With this utility, the following actions can be accomplished: • Set and program the Encoder module’s parameters in EEPROM • Activate the motors in each direction at variable speed •...
Page 186: Exercising The Motors
Using the Roborun Configuration Utility The Time Base parameter is used to compute the speed measured by the module. The measured speed is a relative number ranging from 0 to +/-127 . The relationship between this relative speed number and the actual RPM is based on the Time Base value and the Encoder’s Pulses Per Revolution (PPR) value (see “Using the Encoder to Measure Speed”...
Page 187 Running the Motors FIGURE 105. Motor exercising and monitoring screen 1- Run/Stop Button This button will cause the PC to send the run commands to the controller and will update the screen with measurements received from the controller. When the program is running, the button’s caption changes to “Stop” . Pressing it again will stop the motors and halt the exchange of data between the PC and the controller.
Page 188 Using the Roborun Configuration Utility case the power level will be the one needed to keep the Amps within the limit. Note that the display value is not signed and thus does not provide rotation direction information. The Ana fields contain the analog input values that are measured and reported by the con- troller.
Page 189: Logging Data To Disk
Running the Motors three digital inputs present on the controller. Black represents a “0”level. Green repre- sents a “1” level. 7- Data Logging and Timer A timer is provided to keep track of time while running the motors. An additional set of but- tons and displays are provided to operate a data logger.
Page 190: Connecting A Joystick
Using the Roborun Configuration Utility line of the save file contains the Header names. Each following line contains a complete set of parameters. The Header name, order and parameter definition is shown in Table 36: TABLE 36. Logged parameters order, type and definition Parameter Header Seconds Command1...
Page 191: Using The Console
Using the Console A joystick test program name “Joytest” is automatically installed in the Start menu when installing the Roborun utility. This program may be used to further verify that the joystick is properly installed in the PC and is fully operational. Using the Console The console screen allows you to communicate with the controller using raw ASCII data.
Page 192: Viewing And Logging Data In Analog And R/C Modes
Using the Roborun Configuration Utility ries. See “RS232 Encoder Command Set” on page 155 for the list of Encoder related commands and queries. 3- Keep Watchdog Alive If the controller is in the RS232 mode with the watchdog enabled, then after 1 second of inactivity motors will be stopped if they were one and a “W”...
Page 193: Operating The Ax2550 Over A Wired Or Wireless Lan
Operating the AX2550 over a Wired or Wireless LAN Operating the AX2550 over a Wired or Wireless LAN The Roborun utility supports connection and operation of the AX2550 controller over a Wired or Wireless TCP/IP network. This feature makes it easy to tele-operate and monitor the controller across a lab or across the globe via Internet.
Page 194: Updating The Controller's Software
Using the Roborun Configuration Utility FIGURE 108. Roboserver screenshot when idle Note that it is not possible to use this configuration to change the controller’s parameters or update the controller’s software. Updating the Controller’s Software The AX2550’s operating software can be easily upgraded after it has left the factory. This feature makes it possible to add new features and enhance existing ones from time to time.
Page 195: Creating Customized Object Files
It is possible to create versions of the controller’s firmware with default settings that are different than those chosen by Roboteq. This capability can be used to improve system reli- ability in the unlikely, but not impossible, occurrence of a parameter loss in the controller’s non-volatile memory.
Page 196 Select the latest official controller firmware issued by Roboteq. Select the profile file that was created and saved earlier. Select a revision letter. This letter will be added at the end of Roboteq’s own version identity number. Click on the Create button and save the new customized object file.
Page 197: Section 16 Mechanical Specifications
Mechanical Dimensions Mechanical SECTION 16 Specifications This section details the mechanical characteristics of the AX2550 controller. Mechanical Dimensions The AX2550 is built into a extruded aluminum case which also serves as a heat sink for its electronics. Figure 110 and Figure 111 show drawings of the controller and its mechanical dimensions.
Page 198: Mounting Considerations
Mechanical Specifications 1.60" (40 mm) Program Set Reset 4.00" (102 mm) 5.50" (140 mm) FIGURE 110. AX2550 front view and dimensions 5.50" (140 mm) 4.00" (101.6 mm) 3.00" (76.2 mm) FIGURE 111. AX2550 top view and dimensions Mounting Considerations AX2550 Motor Controller User’s Manual Version 1.9b.
Page 199: Attaching The Controller Directly To A Chassis
Thermal Considerations Mounting brackets on each end are provided for durable assembly of the controller onto any chassis. Optional shock mount absorbers may be added for use in the most brutal environment. Thermal Considerations The AX2550 is built into a heat-sinking aluminum extrusion. The large fin area on the side of the extrusion ensures sufficient heat dissipation for operation without a fan in most applications.
Page 200: Weight
Mechanical Specifications TABLE 37 . AX2550 wire identification and dimensions Wire Power Control or Backup Controller Battery Controller Battery- Weight Controller weight is 3.3 lbs (1500g) AX2550 Motor Controller User’s Manual Gauge Outside Diameter AWG22 0.07” (1.8mm) AWG22 0.07” (1.8mm) Color Length Yellow...

This manual is also suitable for:

Ax2550

RoboteQ AX2850 User Manual

Quick Links

Need help?

Questions and answers

Related Manuals for RoboteQ AX2850

Summary of Contents for RoboteQ AX2850