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.
AX500 Motor Controller User’s Manual Version 1.9b.
Revision History Revision History Date Version Changes June 1, 2007 1.
AX500 Motor Controller User’s Manual Version 1.9b.
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 Connecting the R/C Radio 16 16 Powering On the Controller 17
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 Battery Current vs.
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 7
Reception Watchdog 87 R/C Transmitter/Receiver Quality Considerations Joystick Deadband Programming Command Control Curves 88 88 89 Left/Right Tuning Adjustment 90 Joystick Calibration 90 SECTION 11 Data Logging in R/C Mode 91 Analog Control and Operation 93 Mode Description 93 Connector I/O Pin Assignment (Analog Mode) 94 Connecting to a Voltage Source Connecting a Potentiometer 95 95 Selecting the Potentiometer Value 96 Analog Deadband Adjustment Power-On Safety 97 98 Under Voltage Saf
Query Digital Inputs 111 Reset Controller 111 Accessing & Changing Configuration Parameter in Flash 112 Apply Parameter Changes 112 Flash Configuration Parameters List 113 Input Control Mode 114 Motor Control Mode 114 Amps Limit 115 Acceleration 116 Input Switches Function 116 RC Joystick or Analog Deadband 117 Exponentiation on Channel 1 and Channel 2 117 Left/Right Adjust 118 Default PID Gains 118 Joystick Min, Max and Center Values 119 Reading & Changing Operating Parameters at Runtime Operating Modes Re
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 SECTION 14 Mechanical Specifications Mechanical Dimensions 147 149 149 Mounting Considerations 150 Thermal Considerations 150 Attaching the Controller Directly to a Chassis Precautions to observe 152 151 Wire Dimensions 153 Weight 10 153 AX500 Motor Controller User’s Manual Version 1.9b.
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.
Important Safety Warnings 12 AX500 Motor Controller User’s Manual Version 1.9b.
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.
AX500 Quick Start 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. Connector to Receiver/ Controls and sensors Status LED FIGURE 1. AX500 Controller Front View 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.
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 + Power on/off switch + Fuse VMot M1+ M1VCon GND GND GND M2M2+ VMot Motor1 Controller 12V to 24V Motor Battery Notes: - The Battery Power connection are doubled in order to provide the maximum current to the controller.
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.
Powering On the Controller Channel 3 Channel 2 3: 4: 6: 7: 8: Channel 1 Channel 1 Command Pulses Channel 2 Command Pulses Radio battery (-) Ground Radio battery (+) Channel 3 Command Pulses 8 9 Pin 1 Wire loop bringing power from controller to RC radio 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.
AX500 Quick Start The status LED will start flashing a pattern to indicate the mode in which the controller is in: RC Mode RS232 Mode No Watchdog RS232 Mode with Watchdog Analog Mode 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.
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.
AX500 Quick Start 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.
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.
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 • • • • • • • 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
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 24 • 13 internal parameters, including battery voltage, captured R/C command, temperature and Amps accessible via RS232 port • • • • • Data may be logged in a PC, PDA or microcomputer Efficient heat sinking.
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.
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. VCon VMot M2+ M2- 3 x Gnd M1- Motor 2 M1+ VMot 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.
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.
Connecting Power and Motors to the Controller 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.
Single Channel Operation 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.
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.
Wire Length Limits Fuses are typically slow to blow and will thus allow temporary excess current to flow through them for a time (the higher the excess current, the faster the fuse will blow). This characteristic is desirable in most cases, as it will allow motors to draw surges during acceleration and braking. However, it also means that the fuse may not be able to protect the controller.
Connecting Power and Motors to the Controller It is therefore essential that the AX500 be connected to rechargeable batteries. If a power supply is used instead, the current will attempt to flow back in the power supply during regeneration, potentially damaging it and/or the controller. Regeneration can also cause potential problems if the battery is disconnected while the motors are still spinning.
Using the Controller with a Power Supply 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 regeneration. As discussed in “Power Regeneration Considerations” on page 31, if the supply is not able to absorb and dissipate regenerated current, the voltage will increase until the overvoltage protection circuit cuts off the motors.
Connecting Power and Motors to the Controller 34 AX500 Motor Controller User’s Manual Version 1.9b.
Basic Operation General Operation SECTION 5 This section discusses the controller’s normal operation in all its supported operating modes.
General Operation Selecting the Motor Control Modes For each motor, the AX500 supports multiple motion control modes. The controller’s factory default mode is Open Loop Speed control for each motor. The mode can be changed using any of the methods described in “Loading, Changing Controller Parameters” on page 134. Open Loop, Separate Speed Control In this mode, the controller delivers an amount of power proportional to the command information. The actual motor speed is not measured.
Selecting the Motor Control Modes Controller FIGURE 14. Effect of commands to motors examples in mixed mode Closed Loop Speed Control In this mode, illustrated in Figure 16, an analog tachometer 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.
General Operation Position Feedback Position Sensor Gear box FIGURE 16. Motor with potentiometer assembly for Position operation User Selected Current Limit Settings The AX500 has current sensors at each of its two output stages. Every 16 ms, this current is measured and a correction to the output power level is applied if higher than the user preset value. The current limit may be set using the supplied PC utility. Using the PC utility is it possible to set the limit with a 0.125A granularity from 1.
Battery Current vs. Motor Current The numbers in the table are the max Amps allowed by the controller at a given temperature point. If the Amps limit is manually set to a lower value, then the controller will limit the current to the lowest of the manual and temperature-adjusted max values. This capability ensures that the controller will be able to work safely with practically all motor types and will adjust itself automatically for the various load and environmental conditions.
General Operation Vbat Off Motor On FIGURE 17. Current flow during operation On Off I mot Avg I bat Avg FIGURE 18. Instant and average current waveforms The relation between Battery Current and Motor current is given in the formula below: Motor Current = Battery Current / PWM Ratio Example: If the controller reports 10A of battery current while at 10% PWM, the current in the motor is 10 / 0.1 = 100A. Important Warning Do not connect a motor that is rated at a higher current than the controller.
Programmable Acceleration When using the serial port, acceleration can be one of 24 possible values, selectable using the Roborun utility or entering directly a value in the MCU’s configuration EEPROM. Table 4 shows the corresponding acceleration for all Switch and RS232 settings. Numerically speaking, each acceleration value corresponds to a fixed percentage speed increment, applied every 16 milliseconds. The value for each setting is shown in the table below. TABLE 4.
General Operation an equally large, or possibly larger, regeneration current surge. Always experiment with the lowest acceleration value first and settle for the slowest acceptable value. Command Control Curves The AX500 can also be set to translate the joystick or RS232 motor commands so that the motors respond differently whether or not the joystick is near the center or near the extremes. The controller can be configured to use one of 5 different curves independently set for each channel.
Left / Right Tuning Adjustment % Forward (Motor Output) 100 80 Logarithmic Strong Logarithmic Weak 60 Linear (default) Exponential Weak Exponential Strong 100 80 60 20 0 40 - 20 - 40 - 60 20 - 80 - 100 40 % Command Input 20 Deadband 40 60 80 100 % Reverse FIGURE 19. Exponentiation curves The AX500 is delivered with the “linear” curves selected for both joystick channels.
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 20 100 80 60 60 40 40 20 40 40 60 60 80 5.25% 3% 100 % Reverse 0% % Forward (Motor Output) 100 80 0 20 60 % Command Input - 20 - 40 - 60 20 - 80 - 100 100 80 60 20 0 40 - 20 - 40 - 60 - 80 20 40 80 - 100 % Forward (Motor Output) 0% -3% -5.
Activating Brake Release or Separate Motor Excitation TABLE 6. Left/Right Adjustment Parameter selection Parameter Value Speed Adjustment Parameter Value Speed Adjustment 5 -1.5% 12 4.5% 6 -0.75% 14 5.25% 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. This feature is typically used to activate the mechanical brake release sometimes found on motors for personal mobility systems.
General Operation Special Use of Accessory Digital Inputs The AX500 includes two general purpose digital inputs identified as Input E and Input F. The location of these inputs on the DB15 connector can be found in the section “I/O List and Pin Assignment” on page 50, while the electrical signal needed to activate them is shown on “Connecting Switches or Devices to Input F” on page 52. By default, these inputs are ignored by the controller.
AX500 Connections SECTION 6 Connecting 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. AX500 Connections The AX500 uses a set of power wires (located on the back of the unit) and a DB15 connector for all necessary connections. The diagram on the figure below shows a typical wiring diagram of a mobile robot using the AX500 controller.
Connecting Sensors and Actuators to Input/Outputs 2 4 1 3 3 6 5 7 9 8 1- DC Motors 6- 2- Optional sensors: - Tachometers (Closed loop Speed mode) - Potentiometers (Servo mode) R/C Radio Receiver, microcomputer, or wireless modem 7- Command: RS-232, R/C Pulse 8- Miscellaneous I/O 9- Running Inverted, or emergency stop switch 3- Motor Power supply wires 4- Logic Power supply wire (connected optionally)5- Controller FIGURE 21.
AX500’s Inputs and Outputs When the controller operates in modes that do not use these I/O, these signals become available for user application. Below is a summary of the available signals and the modes in which they are used by the controller or available to the user. TABLE 7.
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 AX500. 9 15 Pin1 8 FIGURE 22. Controller’s DB15 connector pin numbering TABLE 8.
Connecting devices to Output C TABLE 8.
Connecting Sensors and Actuators to Input/Outputs Important warning: This output is unprotected. If your load draws more than 100mA, permanent damage will occur to the power transistor inside the controller. Overvoltage spikes induced by switching inductive loads, such as solenoids or relays, will destroy the transistor unless a protection diode is used. Connecting Switches or Devices to Input E Input E is a general purpose, digital input. This input is only available when in the RS232 and Analog modes.
Connecting Switches or Devices to EStop/Invert Input +5V Out 14 +5V Out 14 +5V In 7 10kOhm Input F 4 10kOhm 10kOhm Input F 4 +5V In 7 Internal Buffer GND In 6 Internal Buffer 10kOhm GND In 6 GND Out 5 GND Out 5 FIGURE 25. Switch wiring to Input F The status of Input F can be read in the RS232 mode with the ?i command string. The controller will respond with three sets of 2 digit numbers.
Connecting Sensors and Actuators to Input/Outputs +5V 14 AX2500 Internal Buffer and Resistor 10kOhm Input EStop/Inv 15 Ground 5 FIGURE 26. Emergency Stop / Invert switch wiring The status of the EStop/Inv can be read at all times in the RS232 mode with the ?i command 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.
Connecting Tachometer to Analog Inputs Connecting the potentiometer to the controller is as simple as shown in the diagram on Figure 28. +5V 14 Ana 1: Ana 2: Ana 3: Ana 4: 11 10 12 8 Internal Resistors and Converter 47kOhm A/D 10kOhm 10kOhm 47kOhm Ground 5 FIGURE 28. 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. The potentiometer axle must be firmly connected to the gear box output shaft.
Connecting Sensors and Actuators to Input/Outputs Since the controller only accepts a 0 to 5V positive voltage as its input, the circuit shown in Figure 29 must be used between the controller and the tachometer: a 10kOhm potentiometer is used to scale the tachometer output voltage to -2.5V (max reverse speed) and +2.5V (max forward speed). The two 1kOhm resistors form a voltage divider that sets the idle voltage at mid-point (2.5V), which is interpreted as the zero position by the controller.
Connecting External Thermistor to Analog Inputs Connecting External Thermistor to Analog Inputs Using external thermistors, the AX500 can be made to supervise the motor’s temperature and adjust the power output in case of overheating. Connecting thermistors is done according to the diagram show in Figure 30. The AX500 is calibrated using a 10kOhm Negative Coefficient Thermistor (NTC) with the temperature/resistance characteristics shown in the table below. TABLE 11.
Connecting Sensors and Actuators to Input/Outputs 100 Analog Input Reading 50 0 -50 -100 11 0 10 0 90 80 70 60 50 40 30 20 10 0 -1 0 -2 0 -150 Temperature in Degrees C FIGURE 31. Signed binary reading by controller vs. NTC temperature To read the temperature, use the ?p command to have the controller return the A/D converter’s value. The value is a signed 8-bit hexadecimal value. Use the chart data to convert the raw reading into a temperature value.
Connecting User Devices to Analog Inputs Measured volts = ((controller reading + 128) * 0.255) -5 Note: The A/D converter’s reading is returned by the ?p command and is a signed 8-bit hexadecimal value. You must add 128 to bring its range from -127/+127 to 0/255. Connecting User Devices to Analog Inputs The two analog inputs can be used for any other purpose. The equivalent circuit for each input is shown in Figure 33.
Connecting Sensors and Actuators to Input/Outputs using the ?m query, or during data logging (see “Analog and R/C Modes Data Logging String Format” on page 126) The analog value that is reported will range from 0 (warmest) to 255 (coldest). Because of the non-linear characteristics of NTC thermistors, the conversion from measured value to temperature must be done using the correction curve below.
Internal Heatsink Temperature Sensors HiTemp = LoTemp + 5; lobound = TempTable[i]; hibound = TempTable[i+1]; temp = LoTemp + (5 * ((AnaValue - lobound)*100/ (hibound - lobound)))/100; return temp; } } AX500 Motor Controller User’s Manual 61
Connecting Sensors and Actuators to Input/Outputs 62 AX500 Motor Controller User’s Manual Version 1.9b.
Mode Description Closed Loop Position Mode SECTION 7 This section describes the AX500 Position mode, how to wire the motor and position sensor 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. The controller will move the motor so that it reaches this position.
Closed Loop Position Mode Position Sensor Selection The AX500 may be used with the following kind of sensors: • • Potentiometers Hall effect angular 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. Sensor Mounting Proper mounting of the sensor is critical for an effective and accurate position mode operation. Figure 35 shows a typical motor, gear box, and sensor assembly.
Feedback Potentiometer wiring manner that will allow it to turn throughout much of its range, when the mechanical assembly travels from the minimum to maximum position. Important Notice: Potentiometers are mechanical devices subject to wear. Use better quality potentiometers and make sure that they are protected from the elements. Consider using a solid state hall position sensor in the most critical applications.
Closed Loop Position Mode Roborun will detect the new hardware revision and display Rev B on the screen. 14 2k 2k 2k - 10k +5V 2k - 10k Command 1 Command 2 Feedback 1 Feedback 2 5 Ground 11 Ana1 10 Ana2 12 Ana3* 8 Ana4* FIGURE 37. Pot wiring for Analog Command and Analog Feedback Analog inputs 3 and 4 have different characteristics than inputs 1 and 2, and so require a lower resistance potentiometer in order to guarantee accuracy.
Sensor and Motor Polarity Feedback Wiring in Analog Mode on Single Channel Controllers When the controller is configured in Analog mode, the analog input 1 is used for commands while the analog input 4 is used for feedback. 14 2k 2k - 10k Command Feedback +5V 5 Ground 11 Ana1 10 Ana2 12 Ana3* 8 Ana4* FIGURE 39.
Closed Loop Position Mode 3. Loosen the sensor’s axle from the motor assembly. 4. Launch the Roborun utility and click on the Run tab. Click the “Start” button to begin communication with the controller. The sensor values will be displayed in the Ana1 and Ana2 boxes. 5. Move the sensor manually to the middle position until a value of “0” is measured using Roborun utility 6. Verify that the motor sliders are in the “0” (Stop) position.
Adding Safety Limit Switches in an attempt to reach a fictitious position. In many applications, this may lead to serious mechanical damage. To limit the risk of such breakage, it is recommended to add limit switches that will cause the motors to stop if unsafe positions have been reached independent of the potentiometer reading. If the controller is equipped with and Encoder module, the simplest solution is to implement limit switches as shown in “Wiring Optional Limit Switches” on page 78.
Closed Loop Position Mode The principal restriction of this technique is that it depends on the controller to be fully functioning, and that once a switch is activated, the controller will remain inactive until the switch is released. In most situations, this will require manual intervention. Another limitation is that both channels will be disabled even if only one channel caused the fault. Manual Emergency Stop Switch SW1 SW2 Motor Ground Controller Emergency Stop Input FIGURE 41.
PID tuning in Position Mode tance between the current and desired positions: when far apart, high power is applied, with the power being gradually reduced and stopped as the motor moves to the final position. The Proportional feedback is the most important component of the PID in 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.
Closed Loop Position Mode Because many mechanical parameters such as motor power, gear ratio, load and inertia are difficult to model, tuning the PID is essentially a manual process that takes experimentation. The Roborun PC utility makes this experimentation easy by providing one screen for changing the Proportional, Integral and Differential gains and another screen for running and monitoring the motors.
Mode Description Closed Loop Speed Mode SECTION 8 This section discusses the AX500 Close Loop Speed mode. Mode Description In this mode, an analog speed sensor measures the actual motor speed and compares it to the desired 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.
Closed Loop Speed Mode Tachometer or Encoder Mounting Proper mounting of the speed sensor is critical for an effective and accurate speed mode operation. Figure 1 shows a typical motor and tachometer or encoder assembly. Analog Tachometer Speed feedback FIGURE 43.
Adjust Offset and Max Speed Important Warning: If there is a polarity mismatch, the motor will turn in the wrong direction and the speed will never be reached. The motor will turn continuously at full speed with no way of stopping it other than cutting the power or hitting the Emergency Stop buttons. Determining the right polarity is best done experimentally using the Roborun utility (see “Using the Roborun Configuration Utility” on page 131) and following these steps: 1.
Closed Loop Speed Mode To set the potentiometer, use the Roborun utility to run the motors at the desired maximum speed while in Open Loop mode (no speed feedback). While the tachometer is spinning, adjust the potentiometer until the analog speed value read is reaching 126. Note: The maximum desired speed should be lower than the maximum speed that the motors can spin at maximum power and no load.
PID tuning in Speed Mode Proportional Gain x E= Error Desired Speed Tachometer dE dt x Σ Output A/D Measured Speed or Integral Gain Optical Encoder dE dt x Differential Gain FIGURE 45. PID algorithm used in 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.
Closed Loop Speed Mode 78 AX500 Motor Controller User’s Manual Version 1.9b.
Diagnostic LED Normal and Fault Condition LED Messages SECTION 9 This section discusses the meaning of the various messages and codes that may be displayed on the LED display during normal operation and fault conditions. Diagnostic LED The AX500 features a single diagnostic LED which helps determine the controller’s operating mode and signal a few fault conditions. The LED is located near the edge of the board, next to he 15-pin connector.
Normal and Fault Condition LED Messages Output Off / Fault Condition The controller LED will tun On solid to signal that the output stage is off as a result of a any of the recoverable conditions listed below. Temporary Fault Permanent Error FIGURE 47. Status LED Flashing pattern during faults or other exceptions • • • • Over temperature Over Voltage Under Voltage “Dead man” switch activation (See “Using the Inputs to turn Off/On the Power MOSFET transistors” on page 46.
Mode Description SECTION 10 R/C Operation This section describes the controller’s wiring and functions specific to the R/C radio control mode. Mode Description The AX500 can be directly connected to an R/C receiver. In this mode, the speed or position information is contained in pulses whose width varies proportionally with the joysticks’ positions. The AX500 mode is compatible with all popular brands of R/C transmitters.
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 the serial port and the PC utility. See “Using the Roborun Configuration Utility” on page 131, and “Accessing & Changing Configuration Parameter in Flash” on page 112 Connector I/O Pin Assignment (R/C Mode) 9 15 Pin1 8 FIGURE 49.
R/C Input Circuit Description R/C Input Circuit Description The AX500 R/C inputs are directly connected to the MCU logic. Figure 50 shows an electrical representation of the R/C input circuit. +5V Output R/C Channel 1 R/C Channel 2 R/C Channel 3 14 Controller Power 3 4 MCU 8 5-13 Controller Ground FIGURE 50. AX500 R/C Input equivalent circuit Supplied Cable Description The AX500 is delivered with a custom cable with the following wiring diagram: 1 2 3 1 8 9 15 FIGURE 51.
R/C Operation 3 2 1 . FIGURE 52. 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. Figure 53 below shows the connector wiring necessary to do this. Figure 54 shows the equivalent electrical diagram.
Connecting to a Separately Powered Radio 14 Controller Power R/C Radio Power 7 R/C Radio R/C Channel 1 3 R/C Channel 2 4 R/C Channel 3 8 R/C Radio Ground 6 5-13 MCU Controller Ground FIGURE 54. 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.
R/C Operation to the controller does not inject power into the controller. The figure below show the cable with the loop cut. Figure 56 shows the equivalent electrical diagram. Channel 3: Channel 2 3: 4: 6: 7: 8: Channel 1 Channel 1 Command Pulses Channel 2 Command Pulses Radio battery (-) Ground Radio battery (+) Channel 3 Command Pulses 8 9 Pin 1 Cut red loop 15 FIGURE 55.
Reception Watchdog the controller captures the full joystick movement, the AX500 defaults to the timing values shown in Figure 57. These vales can be changed and stored as new defaults. joystick position: min center max 1.05ms 0.45ms R/C pulse timing: 0.9ms FIGURE 57. Joystick position vs. pulse duration default values The AX500 has a very accurate pulse capture input and is capable of detecting changes in joystick position (and therefore pulse width) as small as 0.4%.
R/C Operation Note: the Accessory Outputs C will be turned Off when radio is lost. Important Notice about PCM Radios PCM radios have their own watchdog circuitry and will output a signal (normally a “safe condition” value) when radio communication is lost. This signal will be interpreted by the AX500 as a valid command and the controller will remain active. To benefit from the AX500’s radio detection function, you will need to disable the PCM radio watchdog.
Command Control Curves The deadband is measured as a percentage of total normal joystick travel. For example, a 16% deadband means that the first 16% of joystick motion in either direction will have no effect on the motors. TABLE 13.
R/C Operation Left/Right Tuning Adjustment When operating in mixed mode with one motor on each side of the robot, it may happen that one motor is spinning faster than the other one at identically applied power, causing the vehicle to pull to the left or to the right. To compensate for this, the AX500 can be made to give one side up to 10% more power than the other at the same settings.
Data Logging in R/C Mode Data Logging in R/C Mode Output C OFF Output C OFF Output C ON FIGURE 60. Using Channel 3 to activate accessory outputs While in R/C Mode, the AX500 will continuously send a string of characters on the RS232 output line. This string will contain 12 two-digit hexadecimal numbers representing the following operating parameters.
R/C Operation DB9 Female To PC DB15 Male To Controller 1 1 RX Data 6 9 7 10 8 11 9 12 2 2 RS232 Data Out 3 R/C Ch 1 3 4 R/C Ch 2 4 GND 5 5 13 14 15 GND 6 7 R/C GND R/C +5V 8 FIGURE 61. Modified R/C cable with RS232 output for data logging to a PC 92 AX500 Motor Controller User’s Manual Version 1.9b.
Mode Description Analog Control and Operation SECTION 11 This section describes how the motors may be operated using analog voltage commands. Mode Description The AX500 can be configured to use a 0 to 5V analog voltage, typically produced using a potentiometer, to control each of its two motor channels. The voltage is converted into a digital value of -127 at 0V, 0 at 2.5V and +127 at 5V. This value, in turn, becomes the command input used by the controller.
Analog Control and Operation Connector I/O Pin Assignment (Analog Mode) 9 15 Pin1 8 When used in the Analog mode, the pins on the controller’s DB15 connector are mapped as described in the table below TABLE 14.
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 circuitry (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. The inputs’ equivalent circuit is show in Figure 62 below. +5V 14 Internal Resistors and Converter Analog In1: pin 11 In2: pin 10 47kOhm A/D 0V = Min 2.
Analog Control and Operation +5V 14 Internal Resistors and Converter Analog Input 1 2 3 or 4 10kOhm 10 11 12 8 47kOhm A/D 10kOhm 47kOhm 13 Ground FIGURE 63. 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.
Analog Deadband Adjustment Voltage at Input 5V 1K Pot 4V 3V 10K Pot 100K Pot 2V 1V 0V Min Center Max Potentiometer Position FIGURE 64. Effect of the controller’s internal resistors on various potentiometers Analog Deadband Adjustment The controller may be configured so that some amount of potentiometer or joystick travel off its center position is required before the motors activate. The deadband parameter can be one of 8 values, ranging from 0 to 7, which translate into a deadband of 0% to 16%.
Analog Control and Operation TABLE 15. Analog deadband parameters and their effects Parameter Value Pot. Position resulting in Motor Power at 0% Pot. Position resulting in Motor Power at -/+100% 3 (default) 0% to 7.1% 2.32V to 2.68V 95% 4 0% to 9.4% 2.27V to 2.74 93% 0.18V and 4.83V 5 0% to 11.8% 2.21V to 2.80V 95% 0.13V to 4.88V 6 0% to 14.2% 2.15V to 2.86V 94% 0.15V and 4.85V 7 0% to 16.5% 2.09V to 2.91V 96% 0.10V and 4.90V 0.13V to 4.
Data Logging in Analog Mode Data in Analog and R/C Modes” on page 144). It may also be stored in a PDA that can be placed in the mobile robot. The string and data format is described in “Analog and R/C Modes Data Logging String Format” on page 126. The serial port’s output can be safely ignored if it is not required in the application.
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Use and benefits of RS232 Serial (RS-232) Controls and Operation SECTION 12 This section describes the communication settings and the commands accepted by the AX500 in the RS232 mode of operations. This information is useful if you plan to write your own controlling software on a PC or microcomputer. These commands will also allow you to send commands manually using a terminal emulation program.
Serial (RS-232) Controls and Operation Connector I/O Pin Assignment (RS232 Mode) 9 15 Pin1 8 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 16.
Cable configuration Cable configuration The RS232 connection requires the special cabling as described in the figure below. The 9pin female connector plugs into the PC (or other microcontroller). The 15-pin male connector plugs into the AX500. 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). Most connectors have pin numbers molded on the plastic.
Serial (RS-232) Controls and Operation DB9 Female DB9 Male 1 1 RX Data TX Data 6 6 7 7 8 8 9 9 2 3 Data Out 3 Data In 4 4 GND 2 5 5 GND FIGURE 68. RS232 extension cable/connector wiring diagram Communication Settings The AX500 serial communication port is set as follows: 9600 bits/s, 7-bit data, 1 Start bit, 1 Stop bit, Even Parity Communication is done without flow control, meaning that the controller is always ready to receive data and can send data at any time.
Establishing Manual Communication with a PC COM1port. You can easily change this setting to a different port from the program’s menus. Note that starting with version 1.9, the Roborun PC utility also includes a Terminal Emulation Console for communicating with the controller using raw data. See “Using the Console” on page 142.
Serial (RS-232) Controls and Operation This information can be safely ignored and the controller will still be able to switch to RS232 mode upon receiving 10 continuous Carriage Returns as described above. The format of the data logging string and it content is described in Figure , “Analog and R/C Modes Data Logging String Format,” on page 126 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.
RS-232 Watchdog Watchdog time-out If the RS232 watchdog is enabled, the controller will stop the motors and issue a “W” character if it has not received a valid character from the PC or microcontroller within the past 1 seconds. 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.
Serial (RS-232) Controls and Operation TABLE 17.
Controller Commands and Queries !C !c turn C output off turn C output on 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). In most cases, this value is directly related to the command value, except in the conditions described in the notes below.
Serial (RS-232) Controls and Operation Important Notice On the AX500, the number returned by the ?a command must be divided by eight to obtain the actual Amps value Query Analog Inputs Description: This query will cause the controller to return the values of the signals present at its two analog inputs. If the controller is used in close-loop speed mode with analog feedback, the values represent the actual speed measured by the tachometer.
Controller Commands and Queries Query Battery Voltages Description: This query will cause the controller to return values based on two internally measured voltages: the first is the Main Battery voltage present at the thick red and black wires. The second is the internal 12V supply needed for the controller’s microcomputer and MOSFET drivers. The values are unsigned Hexadecimal numbers ranging from 0 to 255.
Serial (RS-232) Controls and Operation Reply: None. Controller will reset and display prompt message 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 parameter setting. It is recommended to use the Graphical configuration utility described in “Using the Roborun Configuration Utility” on page 131.
Accessing & Changing Configuration Parameter in Flash Syntax: ^FF Reply: + Success, changed parameters are now active - if error Table 18 below lists the complete set of configuration parameters that may be accessed and changed using RS232 commands. Flash Configuration Parameters List TABLE 18.
Serial (RS-232) Controls and Operation TABLE 18. Configuration parameters in Flash Location Description Active after ^1B Joystick Max 1 LS Instant ^1C Joystick Max 2 MS Instant ^1D Joystick Max 2 LS Instant ^F0 Amps Calibration Parameter 1 Reset ^F1 Amps Calibration Parameter 2 Reset These parameters are stored in the controller’s Flash memory and are not intended to be changed at runtime. Important Notice The above parameters are stored in the MCU’s configuration flash.
Accessing & Changing Configuration Parameter in Flash This parameters selects the various open loop and closed loop operating modes as well as the feedback method.
Serial (RS-232) Controls and Operation Acceleration Address: Access: Effective: ^03 Read/Write 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.
Accessing & Changing Configuration Parameter in Flash Bit 5:4 Definition See pages Input E Unavailable when Encoder Module is present page 46 page 46 (00) = No action (default) 01 = Cut FET power when Input E is Low 10 = Activate output C 11 = Cut FET when Input E is High 7:6 Input F (00) = No action (default) page 46 01 = Cut FET power when Input E is Low page 46 10 = Activate output C 11 = Cut FET when Input E is High RC Joystick or Analog Deadband Address: Access: Effective: ^06 Read/Write
Serial (RS-232) Controls and Operation This parameter configures the transfer curve that is applied the input command. Bit 7:0 Definition See pages (0) = Linear (no exponentiation - default) page 89 1 = strong exponential 2 = normal exponential 3 = normal logarithmic 4 = strong logarithmic Left/Right Adjust Address: Access: Effective: ^0B Read/Write After Reset or ^FF This parameter configures the compensation curve when motors are spinning in one direction vs. the other.
Reading & Changing Operating Parameters at Runtime Joystick Min, Max and Center Values Address: ^12 - Joystick Center 1 MS ^13 - Joystick Center 1 LS ^14 - Joystick Center 2 MS ^15 - Joystick Center 2 LS ^16 - Joystick Min 1 MS ^17 - Joystick Min 1 LS ^18 - Joystick Min 2 MS ^19 - Joystick Min 2 LS ^1A - Joystick Max 1 MS ^1B - Joystick Max 1 LS ^1C - Joystick Max 2 MS ^1D - Joystick Max 2 LS Instantly Effective: These parameters are the Gains values that are loaded after the controller is reset or powe
Serial (RS-232) Controls and Operation The table below lists the available parameters TABLE 19.
Reading & Changing Operating Parameters at Runtime TABLE 20. Operating Modes Register Definition Bit 1 Function 0: Speed Mode 1: Position Mode 0 0: Analog Feedback 1: Encoder Feedback Read/Change PID Values Address: Access: Effective: ^82 - P1 ^83 - I1 ^84 - D1 ^85 - P2 ^86 - I2 ^87 - D2 Read/Write Instantly The Proportional, Integral and Derivative gain for each channel can be read and changed onthe-fly. This function also provides a mean for setting different PID values for each channel.
Serial (RS-232) Controls and Operation The Controller Status Register can be polled at any time to see if there is a pending fault condition. Any one bit set will cause the controller to turn off the Power Output stage. Conditions marked as Temporary mean that the controller will resume operation as soon as the fault condition disappears. Permanent conditions will cause the controller to remain off until it is reset either by cycling power, pressing the reset button, or sending the %rrrrrr command.
Reading & Changing Operating Parameters at Runtime These registers can be polled to view what the Amps limit is at the current time. This limit normally is the one that is preset by the user except when the controller is operating at high temperature, in which case the allowable current drops as temperature rises. See “Temperature-Based Current Limitation” on page 38. To convert the register value in Amps, divide the reading by 8.
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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. While the AX500 can operate in either RC Radio or RS232 mode, the RS232 Data Input and RC Pulse Input 1 share the same pin on the connector.
Controller is on, Radio is turned Off (or Radio On with RC ch3 Off) • • • Relay deactivates. RS232 is now connected to shared input. String of Carriage Returns now received by controller. Computer looks for OK prompt to detect that the RS232 mode is now active. Note: Wait 5 seconds for the capacitor to discharge before attempting to switch to RC mode if doing this repeatedly. Controller will not reset otherwise.
Decimal to Hexadecimal Conversion Table logging purposes. This cable has a 15-pin male connector and 3 15-pin connectors. The Front View Rear View Female to PC with RxData Only 4 1 3 2 Cut Wire Female to PC with Rx and Tx Data 1 Female to Application 1 Male to controller 1 1 FIGURE 72. ASCII string sent by the controller while in R/C or Analog mode male connector plugs into the controller.
TABLE 23.
Decimal to Hexadecimal Conversion Table TABLE 24.
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SECTION 13 Using the Roborun Configuration Utility A PC-based Configuration Utility is available, free of charge, from Roboteq. This program makes configuring and operating the AX500 much more intuitive by using pulldown 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 Software” on page 146.
Using the Roborun Configuration Utility • after the installation is complete, run the program from your Start Menu > Programs > Roboteq The controller does not need to be connected to the PC to start the Utility.
Roborun Frame, Tab and Menu Descriptions Roborun Frame, Tab and Menu Descriptions 2 1 5 4 3 FIGURE 74. Roborun screen layout The Roborun screen contains the four main set of commands and information frames described below: 1- Program Revision Number This is the revision and date of the Roborun utility. It is recommended that you always verify that you have the latest revision of the utility from Roboteq’s web site at www.roboteq.
Using the Roborun Configuration Utility This is the program’s main frame and includes several types of tabs, each of which has several buttons, menus and other User Interface objects. These tabs and the functions they contain are described in detail in the following sections. Navigate from one set of commands to another by clicking on the desired tab. 4- File and Program Management Commands This frame contains a variety of buttons needed to load and save the parameters from and to the controller or disk.
Loading, Changing Controller Parameters When starting Roborun, this screen is filled with the default values. If the controller is connected to your PC, Roborun will automatically detect it and ask you if you wish to read its settings. The controller’s setting in the PC at can be read any other time by pressing the “Load from Controller” button. After changing a parameter, you must save it to the controller manually by pressing the “Save to Controller” button. Control Settings 1 2 3 4 5 6 FIGURE 76.
Using the Roborun Configuration Utility 4- Emergency Stop or Invert Switch Select This pull down menu allows the selection of the controller’s response to changes on the optional switch input: Emergency Stop, Invert Commands, or no action. See “Emergency Stop using External Switch” on page 45 and “Inverted Operation” on page 45. 5- Effect of Digital Inputs This pull down menu allows the selection of the controller’s response to changes on either of the two digital inputs.
Loading, Changing Controller Parameters accelerate a motor from idle to maximum speed. See “Programmable Acceleration” on page 40. Analog or R/C Specific Settings 1 2 FIGURE 78. Power settings screen The screen shown in Figure 78 slightly changes in function of whether or not the Analog Input mode is selected. If the Analog Input mode is selected on the main screen, then this page is used to set the Analog Deadband value.
Using the Roborun Configuration Utility Closed Loop Parameters FIGURE 79. Closed Loop parameter setting screen The screen shown in Figure 79 is used to set the Proportional, Integral and Differential gains needed for the PID algorithm. These PID gains are loaded after reset and apply to both channels. Gains can be changed individually for each channels and on-the-fly using RS232 commands. These parameters are used in the Position mode (see page 63) and the Closed Loop speed mode (see page page 73).
Running the Motors 1 7 4 3 2 6 8 5 FIGURE 80. 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.
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 controller. When the controller is in the position mode with Analog Feedback, the Ana1 and Ana2 fields will display the position sensed on the feedback potentiometer.
Running the Motors A timer is provided to keep track of time while running the motors. An additional set of buttons and displays are provided to operate a data logger. The data logger is fully described in the section that follows. 8- Joystick Enable Enable and configure a joystick. Logging Data to Disk While running the motors, it is possible to have Roborun capture all the parameters that were displayed on the various fields and charts and save them to disk.
Using the Roborun Configuration Utility TABLE 25. Logged parameters order, type and definition Parameter Header Data type/range Measured Parameter Power2 0 to 127 Same for channel 2 Ana 1, Speed 1, Pos 1 -127 to + 127 or Temp 1 -40 to +150 or Volt 1 0 to 55 Value of sensor connected on analog input 1. Data is automatically converted to the right value and format by Roborun according to the sensor that is being used.
Using the Console development as you will be able to visualize, in real-time, the robot’s Amps consumption and other vital statistics during actual operating conditions. Figure 80 shows the Console Screen and its various components. 3 1 2 4 5 FIGURE 81. Raw ASCII data exchange in Console 1- Terminal Screen This area displays the raw ASCII data as it comes out of the controller. After the controller is reset, it will output a prompt with the firmware’s revision and date.
Using the Roborun Configuration Utility Clicking this button will cause Roborun to send ten consecutive “Carriage Return” character. If the controller is configured in Analog or RC mode, the Carriage Returns will cause it to switch to RS232 mode until the controller is reset again. Viewing and Logging Data in Analog and R/C Modes When the controller is configured in R/C or Analog mode, it will automatically and continuously send a string of ASCII characters on the RS232 output.
Operating the AX500 over a Wired or Wireless LAN To operate over the network, two computers are required, as show in Figure 82 below. The top computer is connected to the controller via its COM port. Both computers are connected to a TCP/IP network. Computer running Roboserver Controller Wired or Wireless 802.11 LAN Computer running Roborun Utility FIGURE 82. Operating the controller over a LAN The computer connected to the controller must run a communication server program named Roboserver.
Using the Roborun Configuration Utility Updating the Controller’s Software The AX500’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. Important Warning Updating the controller will cause all its parameters to reset to their default conditions. You should re-enter these parameters to the desired value prior to re-installing and using the controller.
Creating Customized Object Files Do not reinstall the same firmware version as the one already installed in the encoder module. 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 reliability in the unlikely, but not impossible, occurrence of a parameter loss in the controller’s non-volatile memory.
Using the Roborun Configuration Utility 8- 148 Install the new object file in the controller using the Roborun utility. AX500 Motor Controller User’s Manual Version 1.9b.
Mechanical Dimensions Mechanical Specifications SECTION 14 This section details the mechanical characteristics of the AX500 controller. Mechanical Dimensions The AX500 is delivered as an assembled and tested Printed Circuit Board. The board includes connectors for direct connection to the Optical Encoders and to the Radio, Joystick or microcomputer on one side. On the other side can be found Fast-on tabs for highcurrent connection to the batteries and motors.
Mechanical Specifications 4.20" (106.7mm) 0.15" (3.8mm) 0.15" (3.8mm) 0.15" (3.8mm) 0.15" (3.8mm) 1.25" (31.75mm) 4.20" (106.7mm) 2.00" (50.8mm) 1.10" (74.0mm) 0.15" (3.8mm) 0.15" (3.8mm) 1.875" (47.6mm) 0.15" (3.8mm) 2.90" (73.7mm) FIGURE 86. AX500 top view and dimensions Mounting Considerations The AX500’s heatsink is located at the bottom of the board. This requires therefore that the board be mounted with spacers that are at minimum 0.6” (15mm). 0.6" (15mm) or longer spacer FIGURE 87.
Attaching the Controller Directly to a Chassis board against a vertical surface as shown in the figure below will ensure a better natural convection flow and is, therefore, recommended. FIGURE 88. Mount the controller against a vertical surface to maximize convection flow For high current applications, it is possible that the controller may heat up faster and to a higher temperature than can be dissipated by the using natural convection alone.
Mechanical Specifications Note that the back of the PCB has large copper areas exposed just under the power MOS Board Thermal Pad Metal Interposer Metal Chassis Spacer FIGURE 89. Mount the controller without heatsink against a chassis area. It is critical that the interposer either is insulated (example: anodized aluminum) or a layer of thermal conducting - but electrically insulating - pad is used. Failure to do so will cause a short among the drains of the power MOS and the board will fail.
Wire Dimensions Wire Dimensions The AX500 uses screw terminals for the power connections to the batteries and motors. These connectors are rated to support the controller’s maximum specified current. It is recommended that you use AWG 14 wire for all power connections to ground, batteries and motors. VCon wire and its return Ground may be much thinner as they will never carry current in excess of a couple of milliamperes. Weight Controller weight is 3.
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