SMAC Actuator User Manual
Contents
1. MAGNET HOUSING THERMISTOR MAIN CONNECTOR BOARD i LIMIT SWITCHES TI p JUR COARSE HOME SENSOR ENCODER READER 1 HEAD es EA E x e GLASS SCALE EE i Se ee ete HH Enid Maxim Peer eas He MOUNTING 5 1 RIBBON CABLE SHAFT DC ROTARY MOTOR O RING SEALS COARSE HOME FLAG GEARBOX VACUUM TUBE Fig 1 Actuator Components LAR30 15 shown SMAC equipment required to run a system Linear Actuator only Linear Rotary Actuator LAL series actuator LAR series actuator LAC 1 Controller LAC 25 controller LAH LO D 03 Cable LAH RT D 03 cable Other equipment required RS232 cable and connector appendix page 1 Laptop PC or text editor to construct program see setup instructions 26 pin I O connector for Input Output channels Either 24 Volt D C 4 Amp Power supply 30 37 50 series Or 48 Volt D C 4 Amp Power supply 90 300 series Installation Guide Note Customers manufacturing their own cables please refer to page 7 of this manual for advice on shielding and grounding The actuator must be mounted using the tapped mounting holes provided and users must ensure that mounting surfaces are flat in order to prevent any distorting of the body when the unit is tightened down see Figure 22. 18 LINEAR ENCODER I 19 COIL 20 COIL 21 ROTARY ENCODER A 22 COARSE HOME SENSOR 23 LINEAR ENCODER I 24 ROTARY ENCODER I 25 ROTARY ENCODER I T UNLESS STATED SMAC EUROPE LIMITED X 4 0 5 UNIT 6 CITY BUSINESS CENTRE BRIGHTON ROAD HORSHAM RH13 5 XX 01 TEL 44 1403 276488 FAX 44 1403 256266 X XX 4 0 05 MATERIAL PART NAME DRAWN BY P MARKS par 24 02 99 SCALE TIT ACTUATOR CONNECTOR 17 SMAC The ability to do work and verify its accuracy Actuators User Manual Part 2 Programming Instructions SMAC 5807 Van Allen Way Carlsbad California 92008 USA SMAC Europe Limited Tel 01403 276488 Fax 01403 256266 P Marks 08 00 Revision 1 5 Configuring your Computer To communicate with SMAC controllers any text editor can be used Normally a laptop running Windows 3 1 or Windows 95 NT is used Windows 3 1 1 In program manager select accessories window double click on Terminal 2 If previously configured open SMAC trm and jump to step 8 3 Otherwise select settings from the pull down menu and click on communications 4 Setup as follows Baud Rate 9600 Data Bits 8 Stop Bits 1 Parity None Flow control Xon Xoff Connector COMI Click OK 5 Select settings from the pull down menu and click on Text Transfers 6 Setup as follows Flow control Line at a time Delay between lines 2 10 sec 7 Save SMAC trm 8
3. RAISED MOUNTING SURFACE TAPPED HOLES AND DOWEL POINTS RAISED MOUNTING SURFACE TAPPED HOLES AND DOWEL POINTS Fig 2 Actuator Mounting Points If attaching anything to the rod of the actuator using the threaded part of the rod use the spanner flats provided to prevent the rod rotating Do this with the rotary motor powered off as damage may be caused to the gearbox if it is overloaded turned with the power on 2x FLATS Fig 3 Use spanner flats The actuator housing and controller housing should both be connected to the same grounding point Earth This is usually the case when the units are screwed directly onto a machine chassis If they are not screw mounted then a ground wire should be attached to each of the units and this should be connected to Earth As these are anodized it may be necessary to attach the wire to one of the steel screws or to put a small scratch on the housing to ensure a good connection It is possible to connect the components to different ground points but they must be at the same voltage level Failure to do this may cause a current to flow from one point to another and this may result in noise AC power usually generates the operating voltage e g 24v which is DC and is isolated not connected to earth The power supply has two terminals 24v and Ov This operating voltage is used to generate a 5v DC reference voltage This also has two terminals 5v and Ov These
4. With power to the controller pressing the esc key should give a greater than sign gt indicating the unit is communicating properly Windows 95 or NT 1 Select programs accessories then Hyperterminal Double click on Hypertrm icon If SMAC trm has previously been setup click this icon and jump to step 8 2 Enter name for program e g SMAC trm and choose an icon click OK 3 Phone number window will appear In connect using window choose Direct to COMI click OK 4 COMI properties will appear set as follows Bits per second 9600 Data Bits 8 Parity None Stop Bits 1 Flow Control Xon Xoff Click OK 5 Select file from pull down menu select properties choose settings in properties window 6 Click on ASCII setup set line delay to 250ms click on wrap lines that exceed terminal width Click 7 Select file from pull down menu and save 8 With RS232 connected and power to the SMAC unit pressing the esc key should display a greater than sign gt ann Set up instructions Equipment needed to program and run an actuator is as follows An LAC 1 or LAC 25 controller SMAC cable for connection between controller and actuator SMAC actuator 24v or 48v DC power supply Personal Computer running windows or other text editor RS232 cable for connection between PC and controller The SMAC cable consists of a D sub connector usually 25 pin at the actu
5. this provides the driving force for the system Position of the actuator piston is continually fed back by the linear encoder this is monitored by the controller When the actuator is commanded to make a move through software a trajectory is calculated for the move The position of the actuator piston is monitored over time by the controller and the force output is controlled to match the actual movement to the required movement The difference between the actual position and required position is known as the position error The controller will try to reduce the position error to zero at any time It is also possible to use the actuator without this feedback facility the unit can run loop ignoring the encoder feedback The controller will generate a current through the coil which produces a constant force on the end of the rod If there is no resistance to movement the rod will accelerate due to the applied force Refer to the Actuator User Manual for details of setting up system hardware Programming modes There are three methods with which the actuator can be commanded to move force mode velocity mode and position mode As follows Force Mode Force mode is open loop using no feedback from the encoder Actual position is still monitored but has no effect on the output The commands that are used are as follows MD100 MN QM0 SQ32767 MN motor on QM force mode SQ set force The range of val
6. Connecting inhibit pin 12 to ground pin24 will inhibit the output from the amplifier 13 25 13 10v command signal 25 Ov reference for signal Other pins Not used If a 24V fail safe limit signal is required Active limit OV the following circuit can be used 5V 5 1k i 51k 10 9 8 LIMIT RTN LIMIT LIMIT REED RELAY 5v RS PART NUMBER REED RELAY 5v 291 9675 TOP VIEW RS PART NUMBER 291 9675 TOP VIEW PLC INPUT INPUT OV 424 V 1904 N Limit Switch signal to 24V SMAC The ability to do work and verify its accuracy Appendix 1 Diagrams LAA 5 AMPLIFIER ACTUATOR CONNECTOR FEMALE OUTPUT TO ACTUATOR PIN NO x o a ee N gt Nn NNNNNNYE DESCRIPTION 5 VOLT 5 VOLT RETURN PHASE A PHASE B INDEX OVER TEMPERATURE OVER TEMPERATURE RETURN LIMIT LIMIT RETRACT LIMIT RETURN FAULT INHIBIT I 5 VOLTS TO ACTUATOR FROM CONTROLLER I PASS THROUGH AMPLIFIER PASS THROUGH FROM ACTUATOR I PASS THROUGH FROM ACTUATOR OUTPUT SHUTDOWN BIT OPEN COLLECTOR OPTO AMP ENABLE BIT LED OF OPTO MOTOR POWER TO ACTUATOR COIL PHASE A PHASE B INDEX NOT USED NOT USED NOT
7. two Ov terminals are connected together but still isolated from earth The system will work if these are not connected to earth but problems may arise when the RS232 is connected The RS232 ground is connected to the Ov connection in the controller When it is connected to a PC the ground wire is then connected to earth If this causes problems the following actions will help Plug the power supply to the same AC outlet as the PC Connect the Ov terminal to Earth Note the 0 volt terminal of the controller is connected to the metal shield of the connector As this is screwed into the controller housing the 0 volt is then effectively connected to Earth when the controller housing is grounded Therefore it is not usual to see a problem when connecting a PC to the controller RS232 CONTROLLER P C ACTUATOR OUTLET POWER REY SUPPLY 24V Fig 3 Grounding layout Notes for installation and operation If the actuator is in a vertical plane without a return spring fitted the rod will drop if power to the unit is lost Users must be aware of this as it may damage the end effector being used and also will affect Emergency Stop procedures and re set sequences All units must be operated with a 40 maximum duty cycle this can be calculated as follows of max force applied x of cycle time itis app
8. 0 5000 lu Grippers 40 40 500 5000 Su LAL300 70 300 1500 2000 Rotary Standard LAR 30 37 50 150 200 1500 5000 INm LAR90 20 200 300 1500 It will also be necessary to program the following values These values are nominal and can be changed to suit the motion profile as required during the program Command Mnemonic Value Derivative Sampling Frequency FR 1 Integration Limit IL 5000 Phase PH 0 Sampling rate of integral RI 1 Set Acceleration SA 1000 Set Velocity SV 30000 Set torque SQ 32767 Set Servo speed SS 2 Set following error SE 16383 These values can be displayed at any time by typing the TK tell constants command Note that changing the SS command will alter the SV and SA values produced as these are dependent on the clock speed Registers Part of the non volatile memory NVRAM of the controller is used to create a 256 by 32 bit register space This means that variables can be stored updated and retrieved during execution of a program It is possible to store 32 bit numbers in any of the 255 registers Register 0 is referred to as the accumulator this is regarded as a temporary store for variables The code required to store a number is as follows AL10000 AR220 Accumulator Load value 10000 Accumulator to Register 220 This will store a value of 10000 to register number 220 Typing the command TR220 Tell Register 220 will display 10000 the contents of re
9. 0 SQ0 DH MN SQ10000 WA5 MD6 RL494 IG10 MF MJ7 RA3 AA1 AR3 IG10 MF MJ30 MJ6 MD7 MG ENCODER CHECKED OK MD30 MG ENCODER INOPERATIVE OR ACTUATOR CANNOT MOVE ENCODER TESTING ROUTINE The controller ignores anything after the semi colon Comments etc can be placed here MF RM Motor off reset macros clears the memory MD0 MF PM SQ32767 CF0 CF1 CF2 CF3 CF4 CF5 CF6 CF7 DH AL1 AR3 Motor off enter position mode reset force limit to maximum turn off all channels define home Initialize a counter in register 3 and set it to 1 at the start MD1 AL254 LV27 EV27 Load value 254 into vector 27 overtemp Enable vector 27 MD2 FR1 SG 5 SI 6 SD 7 1L5000 SC2000 RI1 This sets up the PID constants The gain integral and derivative are in registers 5 6 and 7 These values will need to be loaded before the program is run MD3 QM MN SQ 10000 WA5 Select torque mode set force to one third maximum negative value wait 5ms MD4 RL494 1B 10 MF MJ7 RA3 AA1 AR3 IG10 MF MJ5 MJ4 Read axis 1 current position if below 10 counts i e the rod has moved more than 10 counts in a negative direction as expected turn motor off and jump to macro 7 Else read register 3 value add 1 to it store it back into register 3 If this is greater than 10 turn motor off and jump to MDS else jump to the start of macro 4 MD5 AL1 AR3 WA200 SQ0 DH MN SQ10000 WAS5 The program jumps here if it cannot retract the rod Re
10. Either the glass scale of the optical encoder or the reader head is carried by the piston As the piston moves the detector head reads the distance traveled An index line on the glass scale is used as a home location The actuator rod exits the body through the bearing to maintain alignment A Powers linear motion Guides linear motion Adjustable end stops End of stroke sensors Detects overheating Carries coil rod and DC motor Mounted to linear bearing Guides rod through body Measures distance travelled by piston Optical encoder scale Reads the optical scale Locates a fixed position on the scale Rotates the rod Connects motor to rod Measures angular distance traveled Locates a fixed position on the scale Proximity switch to detect rotary home thermistor is present in the actuator to signal an overheating condition Rotary Motion LAR series only The piston to rotate the rod carries an assembly comprising a rotary DC motor magnetic encoder and gearbox The rod is mounted to the piston in a rotary bearing The rod and gearbox shaft are connected using a flexible coupling To locate a home position for the rotary axis the actuator rod carries a flag This flag is sensed by a reflective proximity switch and is identified as the coarse index 25 PIN D CONNECTOR MOVING COIL
11. R PASS THROUGH FROM ACTUATOR TOLERANCES UNLESS STATED X 4 0 5 01 0 05 SMAC EUROPE LIMITED SUITE GA BISHOPS WEALD HOUSE ALBION WAY HORSHAM RH12 AH TEL 44 1403 276488 FAX 44 1403 256266 MATERIAL PART NAME eem BY PMARKS DATE 24 02 99 TITLE SCALE CONTROLLER CONNECTOR 15 ENIRY FOR DATA PATCH CORD GREY WAY RJ11 PLUGS RS PART 446 664 ORANGE o o BLACK BROWN 2 5 Ll Oe i Ww gt 1 amp LAC 25 RS CABLE USING KIT RJ11 TO 9 WAY D SOCKET ADAPTOI RS PART 447 639 SMAC EUROPE LIMITED X 0 5 UNIT 6 CITY BUSINESS CENTRE BRIGHTON ROAD HORSHAM RH13 5BA XX 4 01 TEL 44 1403 276488 FAX 44 1403 256266 4 0 05 MATERIAL PART NAME PRAWN EY D MARKS DATE TITLE SCALE RS 232 CONNECTION 7 D 0000000000000 000000000000 25 WAY ACTUATOR CONNECTOR PIN NO DESCRIPTION 1 5 VOLTS 2 5 VOLTS RETURN 3 AXIS 2 MOTOR 4 LINEAR ENCODER A 5 OVERTEMP 6 COARSE HOME OVERTEMP LIMIT RTN 7 COIL 8 COIL 9 LINEAR ENCODER B 10 AXIS 2 MOTOR 11 LIMIT 12 LIMIT 13 ROTARY ENCODER B 14 LINEAR ENCODER A 15 ROTARY ENCODER A 16 LINEAR ENCODER B 17 ROTARY ENCODER B
12. SMAC The ability to do work and verify its accuracy SMAC Actuator User Manual SMAC 5807 Van Allen Way Carlsbad California 92008 USA SMAC Europe Limited Tel 01403 276488 Fax 01403 256266 P Marks 08 00 Revision 1 5 Contents Description Actuator Working Principals Installation Guide Notes for operation Precautions Grounding and Shielding Advice Using SMAC Amplifiers Appendix Part 2 Configuring your computer Setup instructions Controller Parameters PID values Registers Programmers Notes Sample program Input Output Channels 10 13 22 23 24 25 26 27 32 38 Actuator Working Principles Actuator Components Moving Linear guide Bumpers Limit Switch Thermistor Piston 545022 Bearing Bushing Optical encoder Glass Scale Encoder detector head Index line Rotary encoder Rotary index Rotary Coarse Index Method of operation Linear Motion The piston rides on a linear bearing carriage which slides on the linear guide rail A copper coil is mounted on the piston This coil rides inside a magnet assembly When current flows in the coil a reaction force is produced causing the piston to slide along the guide Bumpers are set at each end of the travel to cushion any impact force that may occur Flags carried by the piston activate limit switches before the end of travel is reached
13. USED NOT USED NOT USED ROTARY COARSE HOME FAULT RETURN INHIBIT RETURN POWER RETURN FORM COIL I PASS THROUGH FROM ACTUATOR TOLERANCES UNLESS STATED X 0 5 4 01 0 05 SMAC EUROPE LIMITED UNIT 6 CITY BUSINESS CENTRE BRIGHTON ROAD HORSHAM RH13 SBA TEL 441403 276488 FAX 44 1403 256266 MATERIAL PART NAME DRAWN BY P MARKS DATE 24 02 99 TITLE SCALE ACTUATOR CONNECTOR LAA 5 AMPLIFIER CONTROLLER CONNECTOR MALE INPUT FROM CONTROLLER PIN NO o DESCRIPTION 5 VOLT 5 VOLT RETURN PHASE A PHASE B INDEX OVER TEMPERATURE 5 VOLTS FROM CONTROLLER PASS THROUGH AMPLIFIER PASS THROUGH FROM ACTUATOR 000000000000 3 o ee a 12 13 14 15 16 17 18 19 20 21 22 23 24 25 PIN 11 ISOLATED OUTPUT MAX CURRENT IC 50mA PIN 12 ISOLATED INTPUT MAX CURRENT 80mA X XX OVER TEMPERATURE RETURN LIMIT LIMIT RETRACT LIMIT RETURN FAULT INHIBIT V SERVO COMMAND PHASE A PHASE B INDEX NOT USED NOT USED NOT USED NOT USED NOT USED ROTARY COARSE HOME FAULT RETURN INHIBIT RETURN V RETURN SERVO COMMAND PASS THROUGH FROM ACTUATOR OUTPUT SHUTDOWN BIT OPEN COLLECTOR OPTO AMP ENABLE BIT LED OF OPTO 10 VOLT COMMAND FROM CONTROLLE
14. VM motor on MN and sets constants force SQ acceleration SA and velocity SV Direction 0 DIO commands the rod to move in a direction which increases the encoder count WA20 allows any initial error to disappear before the program starts checking position error MD101 RW538 1G20 MG FOUND MJ105 RL494 IG5000 MG TOO FAR MJ110 RP The position error is checked RW538 if it is greater than 20 encoder counts display message and jump to MD105 Else read actual position RL494 if greater than 5000 counts display message and jump to MD110 MD105 ST MG POSITION N TP MJ110 Stop motion display message N means no carriage return after message Tell Position then jump to MD110 MD110 PM MN SA5000 SV500000 GH WA50 SQ32767 WS100 MJ100 Enter position mode set acceleration and force higher Issue the go home GH command but wait 50ms before ramping force up to maximum This is needed because if the force is increased immediately then any position error will be taken up possibly deforming the measured component Wait after stop 100ms then jump back to MD100 Notes If the actuator is in vertical orientation it will not be possible to land with a force less than the moving mass of the actuator with the above code This is because when the controller sees a position error it will ramp up to the maximum allowable force in order to overcome that error SQ5000 in this case To overcome this situation it would be desirable to
15. al signal though older units will be single ended Consult SMAC to confirm specification of your unit Single ended signals will consist of encoder Channels A B I 20 Differential signals will have additional channels A A Be Be SU There are two dedicated input and output signals The overtemperature output from the amplifier signals an overheat condition inside the actuator These pins are wired straight through the amplifier from the electronic thermistor circuit inside the actuator and will switch a 5v signal which should be applied across pins 6 4 5v and 7 0v There is also a fault signal that becomes active if the amplifier is overheated This channel is capable of switching between 5 and 30 V at 10 mA across the fault pin 11 and fault return 23 FAUL A 5193 PSesol 1 Amplifier fault Circuit An inhibit input to the Amplifier from the controller will shut off power to the actuator The output from the inhibit signal is 9 V Placing a ground between pins 12 inhibit and 24 inhibit return will cause the amplifier to shutdown output goes to zero 9V 1 12 4 INHIBIT Eva S
16. ator end and either a 15 pin LAC 1 or 26 pin LAC 25 D sub connector at the controller end There is also a green plastic Phoenix power connector ensure this is connected in the correct orientation The RS232 cable consists of a 9 pin D sub connector at one end and a 6 pin telephone type connector at the other To start the system 1 Connect 26 or 15 pin and green power connector to the controller Connect the 24v supply to the controller Refer to the controller manual for the pin assignments Connect the RS232 between the computer and the controller Refer to appendix for wiring diagram for this cable 4 Select appropriate communication on PC Terminal Hyperterminal 5 Check all connections when satisfied all is OK turn on the power 6 Press the esc key the prompt gt sign should appear Type MF to ensure the motor is 10 11 off If using a LAC 25 type 0MF Note typing OMF on a LAC 1 controller will cause the controller to hang up Re power if this occurs Connect the 25 pin to the actuator Select Transfer menu and Send Text File select program to send Type TM 2 Tell Macros to list program Type MSO Macro Sequence to run the program Press the esc key to stop the program MF may need to be typed to turn the motor off if the program is stopped in mid sequence nn Setting the Controller Parameters A PID control algorithm is used to ensure optimum
17. e PS2501 1 4 Inhibit Circuit Diagram Limit switch signals are present on pins 8 extend and pin 9 retract The return pin for both of these is pin 10 They are normally open circuit When the limit switch is activated the resistance across these pins will go to 7kQ This be used to switch a 24V signal A pull up resistor may be necessary across the supply to these pins measuring across the resistor will show the voltage going to zero when the limit is active The case of the amplifier should be connected to a ground point to reduce the effect of any electrical noise that may be present in the system Diagrams of pin assignments for wiring the amplifier can be found in Appendix 1 Pin Number Description of connections 1 2 1 5v 2 5v 5v input from controller often 5v from PC is used 5 1v 0 1v 3 4 5 14 15 16 3 4 5 A B I encoder signals 14 15 16 A B I signals Encoder signals from actuator pass through amplifier to the controller Max operating current 2 140mA 6 7 6 overtemp 7 overtemp rtn A 5v 10mA current limited signal can be switched across pin 6 5v and pin 7 Ov 8 9 10 8 limit 9 limit 10 limit Pull up resistor required 5 Applying a voltage and measuring across the resistor will show Ov when limit is active 11 23 11 fault 23 fault rtn Can switch up to 30V 10mA signal when active 12 24 12 inhibit 24 inhibit rtn
18. e do if command will be executed otherwise it will be ignored n
19. e shield must therefore cover the whole distance between actuator and controller For the shields to work they must be connected to a noise free connection the closer this is to the input the better This means that for the encoder signal cable the shield should be connected to the Ov terminal of the operating voltage at the controller connector The power cable shield should be connected to the actuator ground Earth Drawings are available on request from SMAC Use of SMAC Amplifiers The SMAC amplifier is intended for use in conjunction with generic servo controllers The amplifier runs from an 11 50 Volt DC power supply dependent on the actuator being used In order to achieve maximum power from the largest units LAL90 LAL300 a 48V 5Amp DC supply is required otherwise 24V 5 Amp DC is used The amplifier takes a 10 V signal from the servo controller which is used to generate a 3 Amp output to the actuator This input is connected to pins 13 10V and pin 25 OV reference Encoder pulses pass through the amplifier directly to the controller which must be able to interpret these signals The controller should then adjust its 10 V output to maintain the required trajectory The encoder is powered from the 5v input from the servo card or PC This signal should be 5 1V 0 1V and free of electrical noise The encoder signals are square wave 3 channel TTL level quadrature outputs Most actuators use a differenti
20. em to overshoot the desired condition Large values of derivative gain will cause a slower response but may allow a higher proportional gain to be used without the system oscillating The SMAC controller allows the Proportional SG command Integral SI command and Derivative SD command values to be programmed It is also possible to program associated values to enhance performance Derivative Gain Sample Frequency FR Sample Rate of Integral Gain RI Integral Limit IL The values tabulated overleaf should be used to setup the system initially These may have to be adjusted to suit differing loading conditions actuator orientations etc PID values for SMAC Actuators Note These are starting values only they may need to be adjusted for different load values or actuator orientations Values should work with both LAC 25 and LAC 1 For 0 54 and 0 1 reduce all values by a factor of 5 e g SG25 becomes 565 Linear Actuator Proportional Integral Derivative Integral Encoder SG SI SD Limit IL lu LAS24 20 20 400 5000 Su LAS24 50 50 600 5000 lu LAL30 LAR30 25 50 350 5000 5 LAL30 LAR30 125 130 700 5000 lu LAL37 LAR37 30 50 400 5000 5u LAL37 LAR37 120 200 1200 5000 lu LAL50 LAR50 30 150 400 5000 5 LALS50 LAR50 120 300 1600 5000 lu LAL90 LAR90 30 50 400 5000 5 LAL90 LAR90 60 400 1200 5000 lu LAL90 50 25 50 300 5000 5u LAL90 50 60 100 60
21. follows Assume moves are defined on MD120 MD130 MD120 PM MN MA2000 GO WS100 MC245 MG AT POSITION MJ130 MD130 GH WS100 MC245 MG AT HOME MJ120 MD245 RW538 1G20 MG ERROR MJ246 IB 20 MG ERROR MJ246 RC MD246 MF EP Note PID tuning may influence settling time at position Payload may cause steady state error at position These factors should be taken into account when choosing the amount of error to check for and the time after the move before the check is carried out Low Force at Home If the unit is at rest and the rod is disturbed by an external force either another part of the system or manually by an operator this will also cause a position error to be present To avoid any damage it is useful to reduce the holding force at this rest position therefore bringing the actuator to within its 40 duty cycle The code is as follows MD120 PM MN MA2000 GO WS100 MC245 MG AT POSITION SQ10000 MJ130 MD130 GH WS100 MC245 MG AT HOME SQ10000 MJ120 MD245 RW538 1G20 MG ERROR MJ246 IB 20 MG ERROR MJ246 RC MD246 MF EP Thats Vector interrupts There are some points to note when using interrupts The main point is that the interrupts are only sampled when the program is executing commands It is therefore wise to avoid absolute delays in the program It is often the case that the unit is at a start position waiting for an input channel from a PLC or push button for example to start the program running This co
22. gister 220 on the screen The command MA 220 GO would now be the same as typing MA10000 GO the symbol shows that a register value is to be used Registers could for example be used to set up a counter to record the number of cycles carried out by the actuator We would increase the value in a register by one each time a cycle is completed RA50 AA1 AR50 Register to Accumulator 50 Accumulator Add 1 Accumulator to Register 50 If we execute these commands each time we complete a cycle the value in register 50 will be increased by one each time Preset Variables There are areas in memory allocated to preset internal variables It is possible to access these values at any time during execution of a program This is important during such routines as a soft land measure routine homing routine and for safety or damage checks during the cycle We can access such variables as position error position input values For example to access the current position of axis 1 type RL494 Read Long word at address 494 to accumulator this will transfer the current real position into the accumulator The command TRO Tell Register 0 i e the accumulator will display this value on the screen There is a comprehensive explanation of all these functions along with a list of preset variables on pages 44 51 of the LAC 25 manual or pages 41 48 of the LAC 1 manual Programmers Notes The controllers supplied by SMAC use a program
23. he rod to be moved with a given velocity acceleration force and direction The commands to use are as follows MD100 MN VM SA1000 SV100000 SQ10000 DI0 GO MN motor on VM velocity mode SA set acceleration SV set velocity SQ set force DI direction GO go The SQ range is from 0 32767 DIO direction which increases encoder count extend direction which reduces encoder count retract SA and SV are calculated as follows The controller calculates velocity in terms of encoder counts per update period For example Velocity 10mm s with 5 micron encoder update 200 us standard LAC 1 LAC 25 10mm s x 200 counts mm 2000 encoder counts second 2000 5000 update periods sec 0 4 encoder counts per update period 0 4 x 65536 internal constant 5 26214 10mm s SV26214 For example Acceleration 100 mm s 5 micron encoder update period 200 us 100 mm s 200 counts mm 20000 counts s 20000 5000 update periods s 0 0008 counts update period 0 0008 x 65536 constant SA52 2 100 mm s SA52 The most common application for using velocity mode is the soft land routine where we use the actuator to land with a controlled force onto a component The commands we use for this are as follows MD100 MN VM SA1000 S V50000 5Q5000 DI0 GO WA 50 MD101 RW538 IG50 MG LANDED MJ105 RP MD105 TP MF EP MD100 Starts the actuator moving in a positive direction with l
24. imited velocity and force MD101 Word 538 is the address for the position error if greater than 50 IG50 the next two commands are executed i e the message is displayed and the program jumps to MD105 Otherwise these commands are ignored and the RP repeat command is executed which repeats the macro MD105 Tell Position will display the current position Motor off End Program Position Mode Using position mode the actuator can be moved to various positions along the stroke It is possible to set acceleration velocity and force during the move It is possible to make absolute or relative moves or to store learned positions which can be recalled later in the program The code used for position mode moves is as follows MD100 PM MN SA1000 S V100000 SQ20000 MA1000 GO or MR1000 or MP20 PM position mode MN motor on SA set acceleration SV set velocity SQ set force MA move absolute MR move relative MP move position GO go The number following the move command are the number of encoder counts to move Move Absolute will move the rod to an absolute position from the defined zero position Move Relative will move the rod a relative distance from the current position Move Position will move the rod to a previously defined position requires a learned position LP command to store the position If moving to a number of positions in sequence it will be necessary to pause between the moves as foll
25. lied duty cycle e g 100 force x 40 ofcycletime 40 duty 60 force x 50 ofcycletime 30 duty 40 force x 100 ofcycletime 40 duty Recommendations from SMAC are that this duty cycle must not be exceeded over a one second time period NOTE Failure to observe this duty cycle recommendation will usually result in the actuator sustaining damage through overloading Overloading will overheat the coil and may cause it to deform and touch on the magnet housing If the actuator is in vertical plane with no spring return it will use a certain amount of power just to hold its position If the payload is excessive this alone could be enough to exceed the duty cycle Laws of physics state that Force Mass x Acceleration The actuator has a low moving mass therefore with constant force applied and no load a large acceleration will result This will drive the rod into the endstop on the actuator and may cause damage if it is repeatedly done The actuator is a precision piece of equipment in terms of both force and position Alignment of the linear axis components must be maintained to ensure smooth running of the rod To ensure it remains functioning in the correct manner it is advisable to follow the guidelines Precautions Handle the actuator carefully do not drop it or subject it to excessive shock loading Do not apply excessive side loads to the rod this can lead to increased friction and wea
26. limit the maximum force to a lower value SQ500 for example however it would not then be possible to control the motion of the actuator the rod would just drop under its own weight It is possible to assign values to the minimum and maximum forces used allowing the motion of the rod to be controlled but limiting the maximum force that will be applied The addresses to be used are Word 582 minimum SQ value e g 30000 and Word 534 maximum SQ value e g 0 It is necessary to write values to these words from the accumulator using the WW instruction these commands replace the SQ command To put these values into the soft land routine the code would be as follows MD100 VI PRESS ENTER TO START 99 VM MN AL 30000 WW582 AL0 WW534 SA 1000 V50000 DI0 GO WA20 Note that these values would not work if the actuator were in horizontal because there is no force available to move the rod forward c Position Error Checking The position error checking routine is used to ensure the actuator has reached its target position and has not encountered an obstruction If the unit has not reached position there will be a large position error present which will cause a large restoring force to be generated within the actuator which may exceed the 4046 duty cycle The checking routine consists of a subroutine of two lines which checks that the position error is within a certain range This can be called at any time during the program The code is as
27. ming language similar in structure to assembler code The code is held in non volatile RAM in the controller The language consists of two letter commands followed by a number e g MN Motor On PM Position mode Programs are constructed using lines of code known as Macros these are numbered and the program can be commanded to execute different macros call subroutines and jump to different points dependant on conditions An example of macros might be MD10 QM MN SQ10000 MJ20 MD20 WA1000 MF MD Macro Definition QM Force mode MN Motor On SQ Set Force MJ Macro Jump WA Wait Motor off Notes Macros are started by typing MS macro sequence followed by the number of the first macro to be executed On power up of the unit the program will execute Macro 0 automatically Macros will continue to execute if they are in numerical order otherwise an MJ command is required Default values are usually 0 check controller manual for full list of defaults LAC 25 controllers need to have an axis address e g IMN Axis 1 Motor On 2MN Axis 2 Motor On OMF Axis 1 and Axis 2 Motor Off Note that with an LAC 1 controller these axis labels are not needed and will cause a fault A re power of the unit is necessary in this case Getting Started SMAC systems consist of a controller cable and actuator The controller generates movement of the actuator as commanded by the software A current is output to the coil of the actuator
28. ows MD100 PM MN SA1000 SV100000 SQ20000 MA 100 GO WS20 MA 1000 GO WS500 M A4000 GO WS50 MG FINISHED WS wait stop the value is the number of milliseconds to wait at that position It is possible to program a WSO command All SV SA and SQ values will remain at their previously programmed values it is only necessary to program them if they have to be changed from the previous value n LOOK UP TABLE FOR VELOCITY ACCELERATION VALUES USING LAC 1 LAC 25 UPDATE RATE 200 MICRON ENCODER fete ee ee VELOCITY SV VALUE 2621 13107 131072 262144 524288 1310720 2621440 5242880 ACCELERATION 10 5 50 O 262 1049 2621 10000 5243 20000 10486 a p p rss spe ACCELERATION SA VALUE 1 5 10 15 20 50 100 10 50 00 50 OJN gale RIBIS AB a gt Sample Program Testing the Encoder in a Program Before the actuator can be moved the encoder must be tested If it is not tested and a fault is present a large position error could build up This would then cause a large output signal to be generated resulting in rapid movement and crashing of the actuator into the end stops ENCODER TESTING ROUTINE MF RM MD0 MF PM SQ32767 CF0 CF1 CF2 CF3 CF4 CF5 CF6 CF7 DH AL1 AR3 MD1 AL254 LV27 EV27 MD2 FR1 SG 5 SI 6 SD 7 1L5000 SC2000 RI1 MD3 QM MN SQ 10000 WA5 MD4 RL494 IB 10 MF MJ7 RA3 AA1 AR3 IG10 MF MJ5 MJ4 MD5 AL1 AR3 WA20
29. r on the internal components a Avoid putting the actuator in hazardous environments such as wet dusty very hot gt 50 C very cold lt 0 C Consult gt C SMAC if the actuator is required to work in these environments Other points to note Use the optical index to home the actuator on a regular basis this is especially important when the actuator is being moved around on another axis or subject to vibration Avoid powering the rod into the endstops this is also related to duty cycle Get familiar with the actuator by first using it on a horizontal surface with no load and limited force Shielding and grounding advice for customers manufacturing their own cable Note Using non SMAC cables will invalidate the warranty unless an SMAC engineer checks the cable Shielding Noise from wires carrying the coil power needs to be prevented from leaking out these wires need to be twisted pairs held inside a shielded cable Encoder signals need to be shielded from noise these should also be twisted pairs held inside a separate shielded cable The shield should cover as much of the wire it is shielding as possible This means that the encoder signals shield should start as close to the encoder detector circuit as possible and terminate as close to the controller connector as possible The shield for the coil power lines should follow the same pattern Th
30. response behavior of the actuator to its input commands reducing errors in velocity acceleration and position P Proportional Gain This term determines the overall response of a system to position errors providing an output signal proportional to the error at any time A low Proportional gain provides a system which is very stable doesn t oscillate has low stiffness and possibly large position errors under load A high proportional gain provides high stiffness and small positional errors under load but may be unstable I Integral Gain This term helps the system eliminate positional errors caused by friction or loading by increasing the output to the actuator until the error reduces to zero The error is added or integrated over time and eventually the controller generates a sufficient output to reduce it A low Integral Gain may allow positional errors at rest which depend on the static or frictional loads Increasing the Integral gain will reduce these errors but if it is too high the system may hunt or oscillate at low frequency about the desired position D Derivative Gain This term provides damping and stability to the system by preventing overshoot The controller analyses the change in error over time in effect predicting what the error will be at the next time interval and adjusting the output accordingly A low value of derivative gain allows a fast response to positional errors but may also allow the syst
31. set the counter and define home Turn motor on set force to 1 3 maximum positive and wait 5ms MD6 RL494 IG10 MF MJ7 RA3 AATL AR3 IG10 MF MJ30 M J6 As for macro 4 but try to extend rod If extended turn motor off and jump to macro 7 else increment the counter If counter value is greater than 10 motor off jump to macro 30 else jump to macro 6 MD7 MG ENCODER CHECKED OK Message if all OK MD30 MG ENCODER INOPERATIVE OR ACTUATOR CANNOT MOVE Fault message MD254 MG OVERTEMP MF Over temperature message Sample Routines Softland Routine This routine enables the actuator to land on a surface with a low force for example to measure a component This is done in velocity mode monitoring the position error as the rod is moving with a controlled force It is also possible to set a position window where the component should be located if it is not located within a certain position the rod will retract The code used is as follows MD100 VI PRESS ENTER TO START 99 VM MN SQ5000 SA 1000 S V50000 DI0 GO WA20 MD101 RW538 1G20 MG FOUND MJ105 RL494 1G5000 MG TOO FAR MJ110 RP MD105 ST MG POSITION N TP MJ110 MD110 PM MN SA5000 SV500000 GH WA50 SQ32767 WS100 MJ100 MD100 VI PRESS ENTER TO START 99 VM MN SQ5000 SA 1000 S V50000 DI0 GO WA20 This line waits for a carriage return to be entered via the RS232 port by using the variable input VI command Then the unit enters velocity mode
32. ues for the SQ command from 32767 to 32767 corresponding to maximum force in positive extending the rod or negative retracting directions This will generate an output from the PWM amplifier inside the controller The output is almost linear though towards the higher end of the scale there will be more energy lost through heat generation inside the coil effectively reducing the force generated uses PWM to generate an output to the coil QM1 is a more accurate method to generate a force using one of the Analogue Input channels to monitor the actual current running through the coil The commands for this method of programming would be as follows MD100 SC2000 MN QM1 SQ500 SC set current gain MN motor on QM force mode SQ set force Note that the SC value will need to be programmed to allow feedback to be monitored and outputs modified The range of values for the SQ command are from 1023 to 1023 corresponding to a 5 Amp output generated from the controller The maximum current that is used in the coil of the actuator is 3 Amp therefore the maximum value would be SQ 600 to SQ600 Anything above SQ600 would have no effect on the current passing through the coil This allows us to calculate the resolution of the actuator output Resolution max force 600 For a 100N unit Resolution 100N 600 0 16 N This resolution is effective whether we work in QMO or no Velocity Mode This allows t
33. uld take the form of the following code MD100 WN2 MD101 PM MN SA1000 S V100000 SQ32767 MA3000 GO WS100 GH WS100 MJ100 The Wait On command would cause the program to stop executing until that condition is true This means that the interrupts are not being sampled while the code is waiting for this condition It would be better to use the If On command with the program in a loop which would allow checks to be made while at that position also it would be advisable to add the other checks outlined in this section MD100 IN2 MJ101 NO MC245 RP MD101 PM MN SA 1000 SV100000 SQ32767 MA3000 GO WS100 MC245 GH WS100 MC245 SQ10000 MJ100 MD245 RW538 1G20 MG ERROR MJ246 IB 20 MG ERROR MJ246 RC MD246 MF EP Input Output Channels Note The method of operation of the input output channels on the LAC 1 and LAC 25 are different Please ensure that the correct instructions are followed for the controller that is being used LAC 1 This unit has 8 inputs and 8 outputs operating at 5 volt TTL levels The connector on the controller is a 26 way high density d type connector To activate an input the appropriate pin on the connector labeled input 1 input 2 etc must be connected to a common pin on the connector This is a volt free contact An output will be switched from 0 volts between output pin and common when in the off state to 5 volts when on If this has to be used to switch a 24V signal on a PLC for example a rela
34. y must be used e g RS 291 9675 Refer to LAC 1 user manual for full specification on these signals LAC 25 This unit has 4 inputs and 4 outputs operating at between 5 and 24 volts The connector on the controller is a 26 way high density d type connector To activate an input signal a voltage must be applied to the input pin with the input return connected to ground The output channels can be used to switch a voltage of between 5 and 24 volts dc With the channel in the off state no voltage will be passed With the channel in the on state a voltage will be passed The commands used for these operations are as follows Outputs CN channel on e g CN1 channel 1 on CF channel off e g CF3 channel 3 off These commands will activate de activate an output to switch an external device Inputs WN Wait on e g WN2 wait on channel 2 WF Wait off e g WF0 z wait off channel 0 These commands will cause an absolute wait in the program until the relevant channel becomes activated deactivated IN If On e g INO If on channel 0 IF If Off e g IF6 If on channel 6 These commands will act as a normal if command If the condition is true the two commands following the if statement will be executed otherwise they will be ignored DN Do if On e g DN5 Do if channel 5 on DF Do if Off e g DF7 if channel 7 off If the condition is true on or off the remainder of the command line after th
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