LAD-1 SmartDriver user manual
Contents
1. ES a nee Be ee E een cn sta 8 2 2 TORQUE MODE 8 2 3 SWITCHING MODES 2 2 nca rene 8 ZA xelyadB cL 9 3 ENTERING COMMANDS 3 tratti get etage te n IR MEI en tien s een CE 10 3 1 DOWNLOADING COMMANDS erae t tenant ao ne te rU tn Eee neret dopo exea nn casa exa one ml nee eg deb eeu kun 11 ERAN NIME 11 4 APPENDIX A LAD 1 ERROR CODE 8 4422 4 4424 18 5 APPENDIX B SUMMARY OF LAD 1 8 44 4 42224 221 19 6 APPENDIX C LAD 1 CONNECTOR PIN DEFINITIONS sise 20 SMAC LAD 1 Technical Reference Manual 1 Introduction The LAD 1 is a device capable of allowing a motion controller with only step and direction or count up count down type signals to control a brush type DC servomotor or voice coil actuator thereby allowing those to be used in applications formerly assigned to stepping motors The LAD 1 implements a mnemonic type command instruction set via a standard RS 232 serial communications interface These commands are used to set various operating parameters which are then stored in non volatile memory for automatic retrieval at power up The LAD 1 interfaces to the real world via an onboard PWM DC motor driver a quadrature type encoder interface 8 dedicated optoisolate2. 1 The Output Limit parameters allow the user to specify two output duty cycle limits of which one of these at a time is used as determined by the Output Limit input The Initial Integrator Term and Initial Command parameters are used as pre loads to the current loop error integrator when switching to Torque Mode QM SMAC LAD 1 Technical Reference Manual The Current Gain Threshold parameter is used a comparator value for the In Position signal when the INP Mode input is turned on When the output current as reported by the TC command is at a value equal to or greater than this parameter the In Position output will turn on The Current Gain parameter sets the current loop error gain used when operating in Torque Mode This allows the response of the current error integrator to be adjusted to suit different applications A low value will provide slow response to load changes while a high value will provide quick response If the value is set too low then inadequate control may occur If the value is too high then the system may be unstable A good general value is about 5000 to 8000 Related Commands Command FRn Set Derivative Sampling Period Argument 0 lt n lt 127 Default 0 This command allows for the adjustment of the derivative sampling interval for the servo The period of this interval can be calculated by the following T 1 0 000100 where T is the period in seconds and n is th
3. by the LAD 1 However if commands are downloaded to the LAD 1 from a host computer the ability for line comments can make setup documentation possible and desirable SMAC LAD 1 Technical Reference Manual 3 1 Downloading Commands In many cases such as programming multiple units with the same values it is more convenient to enter commands using a text editor on a host computer and then download that text file to the LAD 1 using a communications program such as ProComm the Microsofts Windows Terminal program Whatever communications software is used it must have the ability to provide a short delay approx 100 mS after transmitting each line to give the LAD 1 time to interpret and store the commands that were just sent 3 2 Commands Command DM Decimal Mode Default Decimal Mode This command causes all numerical input and output to be interpreted as decimal or base 10 Numbers will be output with a leading if they are less than zero Related Commands HM Command DP Define Parameter PIO 0 lt n lt 32767 PI1 0 lt n lt 32767 2 Reserved Reserved Argument Output Limit 0 PIO Initial Integral Term 5 0 lt n lt 32767 x Output Limit 1 Initial Command 1023 lt n lt 1023 Current Threshold PI6 0 lt n lt 1023 Current Gain PI7 0 lt n lt 32767 Default This command allows the user to adjust a number of operating parameters of the LAD
4. input is turned off the In Position output will be turned on when the position following error the TF command is less than or equal to the value set by the Set Error SE command When the INP Mode input is turned on the In Position output will then be turned on when the output current value exceeds the value set by system parameter Current Threshold see Pl and DP commands The Output Limit input is used to limit the maximum output duty cycle of the LAD 1 to one of two levels Output Limit Use Output Limit O Use Output Limit 1 The Parameter Index PI and Define Parameter DP commands are used together to set the values for these different levels see Pl and DP commands The default values for these settings are 10096 duty cycle and 7596 duty cycle The logic state on any of these inputs should be maintained for at least 200 us before changing to guarantee that the input state is recognized 5V Figure 2 Other Inputs 1 2 3 Dedicated Digital Outputs The dedicated outputs include Over Temperature Overflow In Position and Ready Figure shows a circuit example of these outputs The Over Temperature output will turn on when the temperature of the power driver of the LAD 1 exceeds 140 C In this case the output of the LAD 1 will go inactive and will remain that way until the temperature of the driver falls below the 140 C threshold The Overflow signal will turn on when the deviation betwee
5. specified out of the permissible numerical range 2 INVALID COMMAND This error indicates that an invalid or unrecognized command was specified in the command line SMAC LAD 1 Technical Reference Manual 5 Appendix B Summary of LAD 1 Commands DM Decimal Mode DP Define Parameter FR Derivative Sampling Frequency HM Hexadecimal Mode IL Integration Limit PH Phase Parameter Index PL Parameter Load PS Parameter Store Sampling Rate of Integral RT Reset SD Set Derivative Gain SE SetError SG Set Proportional Gain SI Set Integral Gain TC Tell Current TD Tell Derivative Gain TF Tell Following Error TG Tell Position Gain Tell Integral Gain TK Tell K Constants TL Tell Integration Limit TO Tell Optimal Position TP Tell Real Position TQ Tell Torque TS Tell Status VE Tell Version ZZ Dump Memory SMAC LAD 1 Technical Reference Manual 6 Appendix C LAD 1 Connector Pin Definitions SERVO INTERFACE POWER INTERFACE 4 14 gt J1 Power Interface 4 Pin 5 08mm Centers Terminal Block Mating Connector OnShore EDZ95004 Digi Key ED1719 1 Main power return 2 Main V power input 3 Motor output 4 Motor output J2 Servo Interface 15 Pin Female D Sub Mating Connector Digi Key 215M Encoder phase A Encoder phase B Encoder Index 5 VDC 5 VDC Reserved do not use Reserved
6. the frequency and rate of change of command pulses will ultimately determine the velocity profile Unlike a normal open loop stepping motor if command pulses are given at a rate faster than the servomotor can respond the LAD 1 will not lose count The motor will simply lag behind until it is able to catch up 2 2 Torque Mode The LAD 1 is capable of operating in a constant current output mode known as Torque Mode When Torque mode is entered the LAD 1 will no longer operate in a position holding mode Instead it will operate in a constant current output mode with the commanded current being set by the command pulses from the motion controller The maximum usable range of commanded current is from 0 to 1023 counts representing from 0 to 5 Amps of output current although the count is tracked to a command of up to 32767 counts to prevent overflows As with any current source the actual achievable output current will depend upon the load impedance and power supply voltage 2 3 Switching Modes When the PM QM input is turned on the LAD 1 will switch from Position mode PM to Torque mode QM of operation When this occurs the LAD 1 assumes an initial command of zero Also because the constant current loop error integrator is unknown it is set to zero This can present a problem in some applications in the form of a time lag in the output while the command is stepped to its required level and the error integrator ramps up sufficiently to cre
7. SMAC The ability to do work and verify its accuracy SMAC LAD 1 Technical Reference Manual SMAC 5807 Van Allen Way Carlsbad California 92008 USA SMAC Europe Limited Tel 01403 276488 Fax 01403 256266 S M A C 5807 VAN ALLEN WAY CARLSBAD CA 92008 PHONE 1 760 929 7575 FAx 1 760 929 7588 FOR TECHNICAL ASSISTANCE CALL 1 760 929 7575 COPYRIGHT AUTOMATION MODULES INC 2002 SMAC LAD 1 Technical Reference Manual 1 INTRODUCTION 3 2 Ne dr en end end hes 4 1 1 6 2240 4 1 2 DEDICATED DIGITAL S 5 1 2 1 Command Pulse InpUuts carnet Ici otc crederent reete ce ku ron itte 5 1 2 2 Additional Inp ts nei erret ec Ce Ee eoe EE Pre e CAR sites 5 1 2 3 Dedicated Digital Outputs eese 6 1 3 INCREMENTAL ENCODER nnan ness sanis annt 7 1 4 OUTPUT DRIVER INTEREAGCE 2222 tirar ute nnnc nent ange ee RES X Rn ae EROR RR a Kain inan aa din RA SEa siikaa Enae 7 1 5 RS 232 SERIAL N IJ Yd de E 7 2 MODES OF OPERATION ie iret rs ehe oet mener re ire teen 8 2 1 POSITION MODE rennen
8. al Gain Maximum Following Phase and Sense Settings utput Limit 0 E utput Limit 1 PIL utput Limit 2 PI2 utput Limit 3 PI3 nitial Integral Term 4 nitial Command PIS urrent Threshold PI6 rameter Values tegral Gain rivative Gain tegral Limit EEO tegral Sample Rat rivative Sample A 0 x lt UUAA VNHUVNA E UPD DODO 2 rye YS YS YS YH YH YS HS YS YH YH YS YS LHS rrent Gain rmware Revision Related Commands VE Command TL Tell Integration Limit 5000 1 03 Mod516 This command reports the integration limit value of the PID digital filter for the servo Related Commands TG TI TD 16 SMAC LAD 1 Technical Reference Manual Command TS Tell Status This command reports the value of the status word variable whose bit are defined by the following table 0 Reserved Reseved 7 6 Reserved Reseved 8 Enabled Output enabled state 1 enabled 9 NewReset Reset input state 1 on Command VE Tell Version This command reports the firmware revision level Related Commands TK SMAC LAD 1 Technical Reference Manual 4 Appendix LAD 1 Error Code Definitions 1 ARGUMENT ERROR This error indicates that command argument was not given or was
9. ate the necessary output In order to reduce this output lag time in applications that require it two system parameters are available to the user Initial Integral Term PI4 and Initial Command When the LAD 1 switches to QM instead of assuming an initial output of zero the command counter is loaded with the Initial Command Init C parameter This allows the user to preset an output when switching modes In a like manner the error integrator is loaded with the Initial Integrator Term Init I parameter This value is previously arrived at through empirical testing The InitC Mode input allows a further degree of flexibility by substituting the measured value of the actual output current for the Init C parameter when the unit enters QM This allows the unit to automatically keep suppling the same output force when switching from PM to QM Because the command counter is used differently in Torque mode when switching back to position mode by turning off the PM QM input the LAD 1 will have lost its command reference Therefore the command counter is loaded with the current value of the encoder counter and all PID loop SMAC LAD 1 Technical Reference Manual related variables are reset i e following error derivative term etc The motor actuator will need to be homed after operating in Torque mode 2 4 Output Limiting By using the Output Limit input the maximum output duty cycle of the LAD 1 can be set to one of two d
10. d digital inputs and 4 dedicated optoisolated digital outputs and an RS 232 serial communications link 1 1 Specifications Description Filter Algorithm Command Pulse Count 1 Million Quadrature Counts per Second count and or direction state Rate must remain unchanged for 500 nS minimum Dedicated Digital Outputs Ready Over Temp Overflow In Position all optoisolated Communication Interface RS 232 Serial Interface 9600 Baud 8 Bits 1 Stop Bit No Parity XON XOFF Handshake Dedicated Digital Inputs Reset Clear Output_Limit Mode x3 Count Up Step 5VDC only Count Down Direction 5VDC only all optoisolated Table 1 Specifications SMAC LAD 1 Technical Reference Manual 1 2 Dedicated Digital Inputs 1 2 1 Command Pulse Inputs The LAD 1 provides several digital inputs to enhance its operation and to allow for more versatile modes of operation The first of these are the Count Up Step and Count Down Direction inputs Figure 1 shows a circuit example of these inputs Command pulses are accepted from the host motion controller via these inputs Depending on the mode of operation set by the Phase PH command the command pulse inputs will function as either independent Count Up and Count Down or paired as Step and Direction In any case the actual count will take place at the on to off transition of the optoisolated input The state of any Command Pulse input must remain the same for at least 500 ns b
11. do not use Reserved do not use Encoder phase A 10 Encoder phase B 11 Encoder Index 12 Common 13 Common 14 Reserved do not use 15 Reserved do not use J5 RS 232 Comm Interface 6 Pin Modular Jack Mating Connector Digi Key A9093 1 Handshake output 2 Handshake input 3 Receive data input 4 Transmit data output 5 Common 6 5 VDC 20 J6 USER I O User I O Interface 37 Pin Female D Sub Mating Connector Digi Key 237M Over temp output Overflow output In Position output Ready output Reset input return Clear input return Count Up Step input Count Down Dir input return Reserved do not use Reserved do not use Reserved do not use Encoder Index output Encoder phase B output Encoder phase A output Common INP Mode input PM QM Mode input Output Limit input InitC Mode input Over temp output return Overflow output return In Position output return Ready output return Reset input Clear input Count Up Step input return Count Down Dir input Reserved do not use Reserved do not use Encoder Index output Encoder phase B output Encoder phase A output 5V INP_Mode input return PM QM Mode input return Output Limit input return InitC Mode input r
12. e FR command argument For example if the value set by the FR command were 9 then the derivative sample period would be 9 1 0 000100 001000 S or 1 mS This command is useful in tuning the PID servo loop to the inertial properties of the system Related Commands RI Command HM Hexadecimal Mode Default Decimal Mode This command causes all numerical input and output to be interpreted as hexadecimal or base 16 Numbers will be output as 2 4 or 8 digits with leading 0 s if they are positive and leading F s if they are negative Related Commands DM Command ILn Set Integration Limit Argument 0 lt n lt 16 383 Default 0 This command clamps the level of influence that the PID digital filter integral term can use to reduce static position error thereby reducing integral wind up When properly adjusted this can enhance loop stability and operation The Integral Limit IL and Set Integral Gain SI must both be set to a non zero value in order for the integral term to have any effect Related Commands RI SI 12 SMAC LAD 1 Technical Reference Manual Command PL Parameter Load This command causes all set parameters to be restored from non volatile memory Related Commands PS Command PHn Set Servo Phasing Argument 0 lt lt 15 Default 0 This command is used to set the output polarity the encoder phasing and the command counter mode and phasing The polarity of the outpu
13. efore changing in order to be recognized by the LAD 1 Please note that the command pulse inputs are designed l to accept 5VDC signal levels only 390 DHMS ET VW MEE gt ZA CMD_DN DIR 3 8 gt amp Jer o lt 2 CMD_UP STEP 3 gt 7 390 DHMS lt a M Figure 1 Command Inputs 1 2 2 Additional Inputs Additional dedicated inputs include Reset Clear PM QM InitC Mode INP Mode and Output Limit Figure 2 shows a circuit example of these inputs The Reset input is used to reset the device and clear any errors When the Reset input is held on the output will be disabled As Reset is turned off the encoder position as well as the commanded position are both set to zero The Clear input is used to place the LAD 1 in a known state When the Clear input is turned on and then back off the command counter the encoder counter and all values associated with the PID loop are cleared to zero When turned on the PM QM input is used to put the LAD 1 into a constant current output mode of operation known as Torque Mode or QM When this input is then turned off the unit will again return to the Position Mode of operation PM The InitC Mode input determines how the switch to QM will be initialized see section 2 4 Switching Modes SMAC LAD 1 Technical Reference Manual The INP Mode input is used to control the function of the In Position output When this
14. erval for the servo The period of this interval can be calculated by the following T 1 0 000100 where T is the period in seconds and n is the RI command argument For example if the value set by the RI command is 1 then the integral sample period will be 1 1 0 000100 000200 5 or 200 uS This command is useful in tuning the PID servo loop to the inertial properties of the system Related Commands FR Command SDn Set Derivative Gain Argument 0 lt n lt 32 767 Default 0 This command sets the derivative gain term of the PID digital filter loop for the servo Related Commands SG SI IL Command SEn Set Maximum Following Error Argument 0 lt n lt 16 383 Default 16 383 This command is used to set the maximum deviation of the encoder position from the commanded position for the servo that will allow activation of the In Position output signal If the deviation exceeds the programmed value the Position output will be turned off Related Commands TF Command SGn Set Proportional Gain Argument 0 lt n lt 32 767 Default 0 This command sets the proportional gain term of the PID digital filter loop for the servo Related Commands SI SD IL SMAC LAD 1 Technical Reference Manual Command Sin Set Integral Gain Argument 0 lt lt 32 767 Default 0 This command sets the integral gain term of the PID digital filter loop for the servo The Set In
15. eturn
16. ifferent levels The value for the two levels is set by using the Parameter Index and Define Parameter DP commands The proper method for doing this is to first use the Pl command to set the parameter index pointed to the desired system parameter then to use the DP command to set the new value For example PIO DP32767 PI1 DP24576 0 max DC 1 max DC 100 75 L Input L Input OO SMAC LAD 1 Technical Reference Manual 3 Entering Commands Immediately after power up the LAD 1 is ready to accept commands To verify this you can hit the ESC key If everything is working properly this should cause a greater than sign gt prompt to appear on your display If not you need to verify that the power and communications connections are correct and verify the compatibility of the communications protocol Commands are entered via a dumb terminal or host computer such as a PC compatible Commands sent to the LAD 1 should consist of standard ASCII characters and the command lines should be followed by a carriage return Linefeeds are not necessary since they are used for formatting and therefore they are ignored As characters are entered at the keyboard they should be echoed on your display If your display echoes its own transmitted characters you will want to issue the Echo Off EF command otherwise the Echo On EN command which is the default mode should be issued If you enter an invalid command the LAD 1
17. n the commanded input pulse count and the servo motor encoder pulse count exceeds 2047 counts When this occurs the output of the LAD 1 will be disabled The In Position output will be turned on when the deviation between the commanded input pulse count and the servo motor encoder pulse count is less then the value programmed by the Set Error SE command Otherwise this output will be turned off SMAC LAD 1 Technical Reference Manual The Ready output is turned on when the LAD 1 is capable of normal operation In the event of an Over Temperature or Overflow condition the Ready output will be turned off Turning the Reset input on will also cause the Ready output to turn off 5V Figure 3 Dedicated Output 1 3 Incremental Encoder Interface The LAD 1 has a quadrature type encoder interface and the ability to supply 5 VDC at a minimum of 50 mA The phase A phase B and Index inputs are pulled up to 5 VDC with 2 7K resistors The phase A phase B and Index inputs are biased at 2 5 VDC with 2 7K resistors This arrangement will accommodate both open collector and totem pole single ended output encoders or line driver output encoders The phasing of the channels as interpreted by the LAD 1 can be changed via program command The encoder signals are received by a 2632 type line receiver These signals are then passed through the LAD 1 to a 2631 type line driver for optional use by the hosting moti
18. on controller The phasing command will have no effect on these signals 1 4 Output Driver Interface The LAD 1 onboard output driver is a PWM switching amplifier capable of supplying 3 Amps continuous and 6 Amps peak for 200 mS minimum at a switching frequency of approximately 19 531 KHz This driver is intended for driving DC brush type motors or voice coil actuators The driver uses the main power supply input and the peak voltage output to the motor will be nearly that of what is supplied The output phasing of the driver can be changed via the Phase PH command The output driver includes an over temperature sensor If this sensor determines that the driver temperature is greater than 140 C the driver will then be disabled the Over Temperature output will be turned on and the Ready output will be turned off 1 5 RS 232 Serial Interface The LAD 1 communicates with a host computer or a dumb terminal via an RS 232 serial interface The baud rate is fixed at 9600 baud Characters are fixed at 8 bits in length with 1 stop bit and no parity Software XON XOFF handshaking is supported Hardware handshaking is not supported SMAC LAD 1 Technical Reference Manual 2 Modes of Operation 2 1 Position Mode In normal operation the LAD 1 will accept command pulses from the host motion controller For each command pulse the commanded position of the servo motor is either incremented or decremented The LAD 1 does no trajectory planning as
19. t will determine whether the servo is driven in a direction that reduces or increases position error The encoder phase will determine whether the position count will increase or decrease for a valid encoder input sequence The command counter mode will determine Count Up Count Down or Step Direction The command counter phasing will determine the count direction of the command counter To determine the argument to be used with the PH command use the follow table and add the required values together Output Phase Normal 0 Output Phase Reversed Encoder Phase Normal Encoder Phase Reversed Command Mode Count Up Count Down Command Phase Normal 1 0 2 Command Mode Step Direction 0 4 0 Command Phase Reversed 8 The default phasing and sense is equivalent to issuing this command with a argument of 0 Command PI Parameter Index Argument 0 lt n lt 7 Default 0 This command sets the index pointer used by the Define Parameter DP command Whichever of eight special parameters this command is used to point to is the one the DP command will operate on Related Commands DP Command PS Parameter Store This command causes all set parameters to be saved in non volatile memory Related Commands PL SMAC LAD 1 Technical Reference Manual Command Rin Sampling Rate of Integral Argument 0 lt n lt 127 Default 0 This command allows for the adjustment of the PID digital filter integral sampling int
20. tegral Gain SI and Integral Limit IL must both be set to a non zero value in order for the integral term to have any effect Related Commands SG SD IL Command TC Tell Current Output This command reports the output current that is flowing through the load The value will be from 0 to 1023 representing a current of from 0 to 5 amps Command TD Tell Derivative Gain This command reports the derivative gain value of the PID digital filter for the servo Related Commands TG TI TL Command TF Tell Following Error This command reports the following error for the servo This value is the difference between the current command count position or that which is reported by the Tell Optimal TO command and the servo s current real position or that which is reported by the Tell Position TP command Related Commands SE Command TG Tell Proportional Gain This command reports the proportional gain value of the PID digital filter for the servo Related Commands TI TD TL Command TI Tell Integral Gain This command reports the integral gain value of the PID digital filter for the servo Related Commands TG TD IL 15 LAD 1 Technical Reference Manual SMAC Command TK Tell K Constants Argument none This command will display a number of internal settings Example display for the command TK gt TK Pa In De In In De p Proportion
21. will respond with a question mark followed by a code indicating the type of error These codes are listed on page 18 in the appendix If you make a mistake when entering a command you can backspace to correct the error If you are entering commands and change your mind hitting the ESC key will cancel the line and give a new gt prompt Once a command line has been entered and has finished executing hitting the RETURN key will cause the same command line to be re executed Command instructions are intended for use with the following syntax Command Argument CR Or Command Argument Command Argument etc The numerical range of an argument will vary depending on the command with which it is used The mathematical interpretation of the argument will depend on whether the Decimal Mode DM or Hexadecimal Mode HM was the last issued DM is the power on default Both decimal and hexadecimal numbers less than zero should be entered with a preceding minus sign If no argument is given then it will be assumed as 0 It should be noted that commands can be strung together by using commas up to a maximum line length of 127 characters If a command line contains the semicolon character i e gt SG1000 SD5000 Set filter gains lt CR gt then the and anything following it to the end of the line will be ignored This feature is not particularly useful if you are entering commands manually as comments are not retained
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