RoboteQ AX3500 user manual Selecting the Potentiometer Value, Important Notice

Page 130

Selecting the Potentiometer Value

Analog Control and Operation

		+5V	14

								Internal Resistors
		Analog						and Converter
			10					47kOhm

		Input 1
		Input 1
		2	11							A/D

		3	12
		3	12					10kOhm
	10kOhm	or 4	8					10kOhm
	10kOhm	or 4	8					47kOhm
			13					47kOhm
			13

		Ground

FIGURE 86. 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.

Important Notice

The controller will not activate and will display the “no ctrl” message after power up or reset until the analog inputs are at 2.5V

FIGURE 87. The “no control” message indicates that joystick is not centered at power up

Selecting the Potentiometer Value

The potentiometer can be of almost any value. Undesirable effects occur, however, if the value is too low or too high.

If the value is low, an unnecessarily high and potentially damaging current will flow through the potentiometer. The amount of current is computed as the voltage divided by the poten- tiometer’s resistance at its two extremes. For a 1K potentiometer, the current is:

I = U/R = 5V / 1000 Ohms = 0.005A = 5mA

For all practical purposes, a 1K potentiometer is a good minimal value.

If the value of the potentiometer is high, then the two 47K resistors built into the controller will distort the reading. The effect is minimal on a 10K potentiometer but is significant on a

130

AX3500 Motor Controller User’s Manual

Version 1.9b. June 1, 2007

Image 130

Contents AX3500 Dual Channel High Power Digital Motor ControllerUser’s Manual AX3500 Motor Controller User’s Manual Version 1.9b. June 1Date Revision HistoryRevision History VersionAX3500 Motor Controller User’s Manual Revision History General Operation SECTION SECTIONSECTION SECTION SECTION SECTION Programming using built-in Switches and Display AX3500 Motor Controller User’s Manual Do not Connect to a RC Radio with a Battery Attached Important SafetyAvoid Shorts when Mounting Board against Chassis WarningsImportant Safety Warnings Quick Start Locating the Switches and ConnectorsAX3500 What you will needAX3500 Quick Start Connecting to the Batteries and Motors Connecting to the Batteries and MotorsSignal Connecting to the 15-pin ConnectorImportant Warning RC ModePowering On the Controller Connecting the R/C RadioConnecting the R/C Radio Prog and Set button status Button OperationFunction Default Values Default Controller ConfigurationDefault Controller Configuration ParameterConnecting the controller to your PC using Roborun Obtaining the Controller’s Software Revision Number Obtaining the Controller’s Software Revision NumberExploring further = Software version 1.9bSECTION 3AX3500 Motor Controller Overview Product DescriptionAutomatic Joystick Command Corrections Technical featuresMultiple Command Modes AX3500 Motor Controller OverviewHigh Efficiency Motor Power Outputs Technical featuresLow Power Consumption Optical Encoder InputsData Logging Capabilities Advanced Safety FeaturesCompact Open Frame PCB Design Power Connections Connecting Power and Motors to the ControllerPower Connections Controller Power Connecting Power and Motors to the ControllerAnd Main Battery Controller PowerPower Control input is mended Off ConfigurationController Powering Schemes Powering the Controller from a single BatteryPowering the Controller Using a Main and Backup Battery Controller Powering SchemesConnecting the Motors Converting the AX3500 to Single Channel Single Channel OperationSingle Channel Operation Power Fuses Electrical Noise Reduction Techniques Wire Length LimitsPower Regeneration Considerations Wire Length LimitsOvervoltage Protection Undervoltage ProtectionUsing the Controller with a Power Supply Using the Controller with a Power SupplyAX3500 Motor Controller User’s Manual Basic Operation Input Command ModesGeneral Operation Basic OperationOpen Loop, Mixed Speed Control Selecting the Motor Control ModesOpen Loop, Separate Speed Control General OperationClose Loop Position Control Closed Loop Speed ControlSelecting the Motor Control Modes Position Feedback Position Sensor Gear box User Selected Current Limit SettingsTemperature-Based Current Limitation SettingMotor Current = Battery Current / PWM ratio Battery Current vs. Motor CurrentBattery Current vs. Motor Current TemperatureRegeneration Current Limiting Motor Current = Battery Current / PWM RatioSwitches Programmable AccelerationSetting Using Programmable Acceleration17.97% Command Control Curves15 Hex 0.089 secondExponentiation Parameter Value Left / Right Tuning AdjustmentLeft / Right Tuning Adjustment Selected CurveSpeed Adjustment Parameter ValueActivating Brake Release or Separate Motor Excitation Emergency Shut Down Using Controller SwitchesEmergency Stop using External Switch Activating Brake Release or Separate Motor ExcitationUsing the Inputs to turn Off/On the Power MOSFET transistors Special Use of Accessory Digital InputsUsing the Inputs to Activate the Buffered Output Inverted OperationSelf-Test Mode Self-Test ModeEncoder Speed or Position AX3500 Connections Connecting Sensors and Actuators to Input/OutputsAX3500 Connections AX3500’s Inputs and Outputs Connecting Sensors and Actuators to Input/OutputsI/O type AX3500’s Inputs and OutputsActivated Signal depending Pin1I/O List and Pin Assignment Input orConnecting devices to Output C Connecting devices to Output CConnecting Switches or Devices to Input F Important warningConnecting Switches or Devices to EStop/Invert Input Connecting Switches or Devices to EStop/Invert InputConnecting Position Potentiometers to Analog Inputs Analog InputsAna2 Connecting Tachometer to Analog InputsConnecting Tachometer to Analog Inputs Operating ModeAna 3 p12 Ana 1 p11Ana2 p10 Ana 4 p8Temp oC Connecting External Thermistor to Analog InputsConnecting External Thermistor to Analog Inputs Resistance kOhmUsing the Analog Inputs to Monitor External Voltages Internal Heatsink Temperature Sensors Connecting User Devices to Analog InputsInternal Voltage Monitoring Sensors Connecting User Devices to Analog InputsValue Temperature Conversion C Source CodeAnalog LoTemp = i * 5 Internal Heatsink Temperature Sensorselse HiTemp = LoTemp + 5 lobound = TempTablei hibound = TempTablei+1AX3500 Motor Controller User’s Manual RC Pulse Output Overview RC Pulses OutputRC Pulse Output Overview Servo Connection to RevA Controllers Connector Location and PinoutConnecting Servos to Controllers RC Pulses OutputServo Connection to RevB Controllers Connecting to Slave ControllersConnecting to Slave Controllers Pulse Width 1.00ms Pulse Timing InformationCommand Value 1.50msRC Channel Testing Using the PC Utility RC Channel Testing Using the PC UtilityAX3500 Motor Controller User’s Manual Optical Incremental Encoders Overview Connecting and Using the Encoder FunctionOptical Incremental Encoders Overview Recommended Encoder Types Connecting and Using the Encoder FunctionConnecting the Encoder Connecting the EncoderPulse Frequency in Hz = RPM / 60 * PPR Name Cable Length and Noise ConsiderationsMotor - Encoder Polarity Matching Cable ColorVoltage Levels, Thresholds and Limit Switches Voltage Levels, Thresholds and Limit SwitchesWiring Optional Limit Switches Wiring Limit Switches Without Encoders Wiring Limit Switches Without EncodersEffect of Limit Switches Motor 1 FwdMotor 2 Fwd Using the Encoder Module to Measure DistanceUsing the Encoder to Measure Speed Motor 2 RevImportant Notice Using the Encoder to Track PositionUsing the Encoder to Track Position The actual formula is as follows Distance = Destination - Counter value / DividerRS232 Communication with the Encoder Module Encoder Testing and Setting Using the PC UtilityRS232 Communication with the Encoder Module AX3500 Motor Controller User’s Manual Selecting the Position Mode Closed Loop Position ModeMode Description Mode DescriptionPosition Feedback Position Sensor Gear box Position Sensor SelectionSensor Mounting Closed Loop Position ModeFeedback Potentiometer wiring in RC or RS232 Mode Feedback Potentiometer wiringFeedback Potentiometer wiring Feedback Potentiometer wiring in Analog Mode Analog Feedback on Single Channel Controllers Feedback Wiring in RC or RS232 Mode on Single Channel ControllersFeedback Wiring in Analog Mode on Single Channel Controllers Analog Feedback on Single Channel ControllersUsing Optical Encoders in Position Mode Sensor and Motor PolarityAdding Safety Limit Switches Important Safety WarningEncoder Error Detection and Protection Encoder Error Detection and ProtectionFIGURE 62. Safety limit switches interrupting power to motors Control Loop Description Using Current Limiting as ProtectionUsing Current Limiting as Protection PID tuning in Position Mode PID tuning in Position Mode Applied Power = Command Value - Actual Position * Proportional GainAX3500 Motor Controller User’s Manual Closed Loop Speed Mode Selecting the Speed ModeTachometer or Encoder Mounting Using Optical Encoder for Speed FeedbackDigital Optical EncodTachometer wiring Closed Loop Speed ModeSpeed Sensor and Motor Polarity Speed Sensor and Motor PolarityAdjust Offset and Max Speed PID tuning in Speed Mode PID tuning in Speed ModeIn Speed Mode, the Integral component of the PID is the most important and must be set first. The Proportional and Differential component will help improve the response time and loop stability Use of the LED Display Normal and Fault Condition LED MessagesUse of the LED Display Possible Display Motor Direction StatusNormal and Fault Condition LED Messages MotorFault Messages Fault MessagesNo Control Rapidly FlashingPermanent Faults Temporary FaultsSelf-Test Display = Software version 1.9b Self-Test DisplayAX3500 Motor Controller User’s Manual SECTION 12 R/C Operation Pin1 Connector I/O Pin Assignment R/C ModeSelecting the R/C Input Mode R/C OperationSupplied Cable Description R/C Input Circuit DescriptionR/C Input Circuit Description FIGURE 74. RC Cable wiring diagram Powering the Radio from the controllerFIGURE 75. RC connection cable Powering the Radio from the controller Connecting to a Separately Powered Radio Operating the Controller in R/C modeReception Watchdog Reception WatchdogImportant Notice about PCM Radios R/C Transmitter/Receiver Quality ConsiderationsDeadband Parameter Value Joystick Deadband ProgrammingJoystick Deadband Programming Deadband as Percent of full Joystick TravelLeft/Right Tuning Adjustment Joystick CalibrationAutomatic Joystick Calibration Automatic Joystick CalibrationData Logging in R/C Mode On before entering joystick calibrationDB15 Male Data Logging in R/C ModeTo Controller AX3500 Motor Controller User’s Manual Analog Control and Operation Connector I/O Pin Assignment Analog Mode Analog Control and OperationConnecting a Potentiometer Connecting to a Voltage SourceConnecting to a Voltage Source Selecting the Potentiometer Value Analog Deadband Adjustment Data Logging in Analog Mode Power-On SafetyUnder Voltage Safety Motor Power at 0%Data Logging in Analog Mode AX3500 Motor Controller User’s Manual Use and benefits of RS232 Serial RS-232 Controls and OperationUse and benefits of RS232 Connector I/O Pin Assignment RS232 Mode Serial RS-232 Controls and OperationExtending the RS232 Cable Cable configurationCable configuration 9600 bits/s, 7-bit data, 1 Start bit, 1 Stop bit, Even Parity Communication SettingsEstablishing Manual Communication with a PC Establishing Manual Communication with a PC RS232 Communication with the Encoder ModuleRoboteq v1.9b 06/01/07 s Entering RS232 from R/C or Analog mode Data Logging String in R/C or Analog modeCommand Acknowledgement Commands Acknowledge and Error MessagesRS232 Mode if default Command ErrorCommand Controller Commands and QueriesRS-232 Watchdog TypeQuery Power Applied to Motors Set Motor Command ValueSet Accessory Output Controller Commands and QueriesQuery Amps from Battery to each Motor Channel Syntax?r or ?R Query Analog InputsQuery Heatsink Temperatures ?m or ?MQuery Digital Inputs Query Battery VoltagesReset Controller ExamplesAccessing & Changing Configuration Parameter in Flash Accessing & Changing Configuration Parameter in FlashApply Parameter Changes Read parameterLocation Flash Configuration Parameters ListActive after Access Input Control ModeMotor Control Mode After ResetAcceleration Amps LimitDefinition Input Switches Function Exponentiation on Channel 1 and Channel Left/Right AdjustRC Joystick or Analog Deadband 08 - Channel0B - Encoder Default Encoder Time Base 1 andDefault Encoder Distance Divider 0C - Encoder0F - Proportional Gain Default PID GainsJoystick Min, Max and Center Values 10 - Integral GainReading & Changing Operating Parameters at Runtime Reading & Changing Operating Parameters at RuntimeAccess Read/Write Effective Instantly Operating Modes RegistersRead/Change PID Values 80 - ChannelAddress Access Read/Write Effective Instantly PWM Frequency RegisterController Status Register Fault ConditionModel or Function Controller Identification RegisterCurrent Amps Limit Registers 8B - ChannelRead Encoder Counter RS232 Encoder Command SetSet/Reset Encoder Counters and Destination Registers RS232 Encoder Command Set7 Set Encoder 1 destination register with value in buffer Read Speedq or !Q n 8 Set Encoder 2 destination register with value in bufferRead Distance Read Encoder Limit Switch StatusRead Speed/Distance Switch Important NoteRead / Modify Encoder Module Registers and Parameters n ValueParameter Description SizeEncoder Hardware ID code Switch StatusRegister Description Address *84Counter 1 and Speed or Distance 1 orCounter Read/Write Mailbox Destination Register 1 andTime Base 1 and Distance 1 andSpeed 1 and Encoder ThresholdDefault Value Counter Read Data FormatRC Pulse Outputs Activation Counter Read Data Format32-bit Hex DecimalController Output Automatic Switching from RS232 to RC Mode Automatic Switching from RS232 to RC ModeAnalog and R/C Modes Data Logging String Format 00 11 22 33 44 55 66 77 88 99 AA BB CCData Logging Cables Decimal to Hexadecimal Conversion Table Decimal to Hexadecimal Conversion TableAX3500 Motor Controller User’s Manual Decimal to Hexadecimal Conversion Table AX3500 Motor Controller User’s ManualAX3500 Motor Controller User’s Manual Programming using built-in Switches and Display SECTION 15 Configuring the Controller using the SwitchesProgramming Methods Configuring the Controller using the Switches Entering Programming ModeProgram The Special Case of Joystick Calibration Changing parametersProgramming using built-in Switches and Display Programmable Parameters List Restoring factory defaultsExiting the Parameter Setting Mode This manual is for software version 1.9bcannot be selected using the switches Possible Values defaultFor safety reasons, the modes below Programmable Parameters ListOrder Downloading and Installing the Utility SECTION 16 Using the Roborun Configuration UtilitySystem Requirements Connecting the Controller to the PC Using the Roborun Configuration Utility1- Program Revision Number Roborun Frame, Tab and Menu DescriptionsRoborun Frame, Tab and Menu Descriptions 2- Controller and Communication Link Information4- File and Program Management Commands Getting On-Screen Help3- Parameter Selection and Setting and Special Functions 5- View Controller Connector PinoutLoading, Changing Controller Parameters Control SettingsLoading, Changing Controller Parameters 1- Controller Input4- Emergency Stop or Invert Switch Select Power Settings3- Input Command Adjustment 5- Effect of Digital Inputs3- Acceleration Setting Analog or R/C Specific SettingsLoading, Changing Controller Parameters 2- Left/Right Adjust 1- DeadbandEncoder Setting and Testing Closed Loop ParametersEncoder Module Parameters Setting Encoder Setting and TestingExercising the Motors RC Output TestingViewing Encoder Data Running the Motors Running the Motors1- Run/Stop Button 2- Motor Power setting3- Measurement 6- Input Status and Output Setting 4- Real-Time Strip Chart Recorder5- Transmit and Receive Data 8- Joystick Enable Logging Data to Disk7- Data Logging and Timer 4- Reset Timer buttonData type/range Connecting a JoystickParameter Header Measured Parameter2- Command Entry Using the Console1- Terminal Screen 4- Send Reset String Viewing and Logging Data in Analog and R/C ModesLoading and Saving Profiles to Disk Viewing and Logging Data in Analog and R/C ModesOperating the AX3500 over a Wired or Wireless LAN Updating the Controller’s Software Updating the Controller’s SoftwareCreating Customized Object Files Updating the Encoder SoftwareCreating Customized Object Files AX3500 Motor Controller User’s Manual Mechanical Dimensions Mechanical SpecificationsMechanical Dimensions Thermal Considerations Mounting ConsiderationsMechanical Specifications Attaching the Controller Directly to a Chassis Attaching the Controller Directly to a ChassisPrecautions to observe Weight Wire DimensionsWire Dimensions AX3500 Motor Controller User’s Manual Mechanical SpecificationsVersion 1.9b. June 1

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