Drive Application Software Application Set Application Set Title Drive Product File Name for (AS) Date – Firmware Rev. Position_Follower PowerFlex 700S Phase II Drive AS_PF700SII_PositionFollower_A.dno 02/06/06 3.01 Attention: This document and related file(s) are designed to supplement configuration of the listed drive product. The information provided does not replace the drive products user manual and is intended for qualified personnel only. Description: Position Follower application is designed to “follow” the encoder feedback from another machine section (the master). The speed loop and position loop in the PowerFlex 700S Phase II drive will be used to synchronize the speed feedback encoder of the follower PowerFlex 700S Phase II motor to the master encoder. Electronic gearing can be used to match the speed of (2) machines with different gear ratios or electronic gearing can be used to make the (2) machines run at different ratios. Limitations: Requires that the motors connected to each PowerFlex 700S Phase II drive have encoders. Options & Notes: Default configuration for 3Wire Control through digital inputs may be changed to 2Wire Control or for operation through 20-COMM-x module. After downloading *.dno file, the Fdbk Config, Pwr Circuit Diag, Direction Test, Motor Tests, and Inertia Measure parts of the Startup routine should be performed to auto-tune the Power Flex 700S Phase II drive to the motor. Drive Input & Output Connections: Inputs Function DI 1 DI 2 DI 3 Jog 1 DI 4 DI 5 DI 6 AI 1 AI 2 AI 3 Encoder 0 (Primary) Encoder 1 (Secondary) Outputs DO 1 DO 2 DO 3 AO 1 AO 2 AO 3 Description This Option is used to independently jog the PF700S2 follower drive when the drive is not operating as a position follower. Start Stop PF700S Motor Feedback Feedback from master Function AS_PF700SII_PositionFollower_A.doc Form Revision – A Page 1 of 4 Encoder Input 0 is wired to the quadrature encoder on the PF700S2 Motor. Encoder Input 1 is wired to the master encoder. Description Drive Application Software Application Set Parameter Configurations Changes from Default Parameter Settings Par Name Value 10 Speed Ref 1 11 Speed Ref 1 Div 29 Jog Speed 1 32 Accel Time 1 33 Decel Time 1 90 Spd Ref BW 10 151 Logic Command 232 242 Encoder0 PPR Encoder1 PPR 1024 1024 740 Position Control b01 = 1 742 Posit Ref Sel 743 [Aux Posit Ref] 745 PositRef EGR Mul 1 746 PositRef EGR Div 1 753 Posit Offset 1 0 755 Posit Offset Spd 175 RPM 768 PositRef P Gain 4 775 Xreg Spd LoLim -175 RPM 776 Xreg Spd HiLim 175 RPM 146 FW Task Time Sel AS_PF700SII_PositionFollower_A.doc Form Revision – A Page 2 of 4 Link 241 1 100 RPM b13 = 1 1AuxPosit Ref 240 2 Description Speed feedback from Encdr1 (master) becomes the speed reference for the PF700S2. Sets the ratio between the master speed reference and the PF700S2 follower. See notes on setting the gear ratio and speed reference scaling. Set per application requirements. Set to a value lower than the master accel. Or the speed ramp can be disabled by turning on bit 0 in p151 [Logic Command]. Set to a value lower than the master decel. Or the speed ramp can be disabled by turning on bit 0 in p151 [Logic Command]. Gain of the speed loop. The speed loop should be tuned before enabling the position loop. See the PowerFlex700S Reference Manual for tuning tips. Bit 13 can be turned on/off to enable/disable the position loop. Sets the PPR for the motor feedback. Sets the PPR for the master encoder. Bit 1 is turned on to send the output of the position loop to the speed regulator. Sets the position loop to follow the auxiliary position reference, which in this case will be Encdr1 Position. Encoder counts from Encdr1 (master) becomes the position reference. This sets the multiplier for the position reference electronic gear ratio. The settable range is -2000000 to +2000000. See notes on setting the gear ratio. This sets the divider for the position reference electronic gear ratio. The settable range is 1 to 2000000. See notes on setting the gear ratio. This sets a position offset to advance or retard the follower if necessary. This can be set from a PLC and can be a positive or negative value. See notes on using the position offset. Sets the speed change used to advance or retard the follower when a value set in p753. Set per application requirements. Sets the proportional gain for the position loop. Set to 1/5th (20%) of p90 after tuning the speed loop. Sets the negative speed limit for the output of the position loop. This should be set the same as the negative value of p755 [Position Offset Spd]. Sets the positive speed limit for the output of the position loop. This should be set the same as the positive value of p755 [Position Offset Spd]. Selects the regulators task time. Drive Application Software Application Set Par 147 Name FW Functions En Value b16=1 827 DigIn3 Sel Jog 1 828 829 DigIn4 Sel DigIn5 Sel Start Normal Stop Link Description Enables the position regulator task. Used to independently jog the PF700S2 follower when the position loop is disabled. Start input for 3Wire Control. Stop input for 3Wire Control. Notes for jogging the PowerFlex 700S Phase II follower drive independently: Command Jog 1 through a digital input or communication network. During a jog command, the position loop output of the drive is automatically disabled. Notes for controlling the position offset of the PowerFlex 700S Phase II follower drive: Before advancing or retarding the PowerFlex 700S Phase II follower drive, p755 [Posit Offset Spd] needs to be set to a value other than 0. p755 [Posit Offset Spd] sets the speed change used to advance or retard the follower. During the advance or retard operation it is added or subtracted from the speed the follower already running. p755 [Posit Offset Spd] is in units of RPM’s, and is set to a positive value. p755 [Posit Offset Spd] can remain set throughout the PowerFlex 700S Phase II follower’s normal operation. To advance or retard the follower using a relative position offset, perform the following steps: 1. Add a value (in counts) in p753 [Posit Offset 1]. For a positive move, add a positive value to p753. For a negative move, add a negative value to p753. For example, with a 1024 ppr encoder, add a value of 4096 to p753 to advance the follower forward one motor revolution. To advance or retard the follower using an absolute position offset, perform the following steps: 1. Set a value (in counts) in p753 [Posit Offset 1]. For a positive move, set p753 to a positive value. For a negative move, set p753 to a negative value. For example, with a 1024 ppr encoder, set p753 to a value of 4096 to move forward one motor revolution. 2. After the move is done, set p740 [Position Control], bit 5 “X Offset Ref” to a 1. 3. Set p753 [Posit Offset 1] = 0. 4. Set p740 [Position Control], bit 5 “X Offset Ref” to a 0. p753 [Posit Offset 1] and p740 [Position Control] can be controlled over a communication network. Notes for setting the gear ratio and speed reference scaling on the PowerFlex 700S Phase II follower drive: Example 1: Matching speeds of (2) machines with different gear ratios In this example, the encoders are mounted on the motors. There is a gear box between each motor and each machine. Each gear box has a different ratio. We want to match the speeds on the output side of the gear box (machine side). Here is the given information: PPRm =1024 PPR PPRf = 1024 PPR Inputm : Outputm = 533:236 Inputm : Outputf = 533:163 where PPRm = the PPR of the master encoder PPRf = the PPR of the follower encoder Inputm : Outputm = gear ratio of master gear box (number of input teeth : number of output teeth) Inputf : Outputf = gear ratio for follower gear box (number of input teeth : number of output teeth) p 745 PPR f • Input f •Output m 1024 • 533 • 236 = = p 746 PPR m • Input m •Output f 1024 • 533 • 163 AS_PF700SII_PositionFollower_A.doc Form Revision – A Page 3 of 4 Drive Application Software Application Set Solving for the lowest common denominator, the 1024s on the top and bottom cancel out and the 533s on the top and bottom cancel out so that: p 745 236 = p 746 163 Therefore, P745 [PositRef EGR Mul] = 236 and P745 [PositRef EGR Div] = 163. This will close the position loop and the angular velocities of the master and follower will match exactly. p11 [Speed Ref 1 Div] is calculated: p11 = Input m •Output f Input f •Output m = 533 • 163 = 0.6907 533 • 236 Notice that the encoder PPRs should not be included in the calculation for P11. This parameter is rounded to the 4th decimal place. The position loop gear ratios will be exact, so that the master and follower track exactly. Example 2: Using electronic gearing to make the (2) machines run at different ratios. In this example the encoders are mounted on the motors. The motors are directly coupled to the load and we want the follower to run at 4 times the speed of the master. PPRm =1024 PPR PPRf = 1024 PPR Ratiof : Ratiom = 4:1 where; PPRm = the PPR of the master encoder PPRf = the PPR of the follower encoder Ratiof : Ratiom = the desired ratio between the follower speed and the master speed p 745 PPR f • Ratio f 1024 • 4 = = p 746 PPR m • Ratio m 1024 • 1 Solving for the lowest common denominator, the 1024’s on the top and bottom cancel out so that: p 745 4 = p 746 1 Therefore, P745 [PositRef EGR Mul] = 4 and P745 [PositRef EGR Div] = 1. This will set up the position loop of the follower to move 4 counts for every 1 count of the master. p11 [Speed Ref 1 Div] is calculated: p11 = Ratio m 1 = = 0.25 Ratio f 4 Notice that the encoder PPR’s should not be included in the calculation for p11. This parameter is rounded to the 4th decimal place. The position loop gear ratios will be exact, so that the follower tracks at 4 times the master’s speed. AS_PF700SII_PositionFollower_A.doc Form Revision – A Page 4 of 4