1、User C Programs in Power PMACMay 2011Priorities for C Programs in Power PMAC pare interrupt: Fast updating to/from PMAC3 ICPhase interrupt: “User-written phase” functionTypically for specialized commutation and current-loop algorithmsFor mutation tasks, use extra motorServo interrupt: “User-written

2、servo” functionTypically for specialized feedback and feedforward algorithmsFor non-servo tasks, use extra motorReal-time interrupt: “Real-time C PLC” functionEquivalent of Turbo PMAC PLCC0Each background scan: “Background C PLC” functionsCalled between each scan of one background Script PLC32 separ

3、ate programs (0 31), separately enabledGeneral-purpose operating system: C programs (applications)Run as programs (not called functions) on standard computerLinux GPOS allocates CPU time (when free from interrupt tasks)Creating C Routines and ProgramsPower PMAC IDE provides tool set for implementing

4、 C routinesProject manager to organize all C and Script softwareSmart text editor for writing software (or pasting in from other source)GNU C piler automatically invoked on project “build”In Project Managers “Solution Explorer”, expand “C language” branchFor user-written servo and/or phase, expand “

5、Realtime Routines”, then select “usrcode.c” for editing (multiple routines can be in this file)For RTI CPLC, expand “CPLCs” and “rticplc”, then select “rticplc.c” for editingFor background CPLCs, click on “CPLCs” and select program number (nn = 0 to 31) in resulting window, creating “bgcplcnn” subfo

6、lder and “bgcplcnn.c” file for editingFor background applications, expand “Background Programs”, and add your own files for editingTo compile and download code, right-click on project name, then select “Build and Download All Programs”IDE Support for C ProgrammingAccessing Shared Memory and Structur

7、esAll files with C code must start with “#include ”Header file provides access to shared-memory structuresAccess for both “real time” (interrupt-driven) and “general-purpose” (background) codeFunctions called by Power PMAC control code (user-written phase and servo, RTI and background CPLCs) automat

8、ically have access to several pre-defined pointerspshm: Pointer to SHM shared-memory data structurepiom: Pointer to I/O memory spacepushm: Pointer to user-defined buffer memory spaceIndependent background programs must declare variables for these pointersStructure elements are basically the same as

9、in the Script environmentCase-sensitive names in C (not in Script)No write-protection in C (but no access to many “internal” elements)Only full-word elements in I/O structuresC User-Written Servo RoutinesEach servo update period, every active motor calls its specified servo routine (built-in or user

10、-written) as functionEach motor can have its own routineCan provide own name(s) for user-written routine(s)Routine must return a “double” value for servo command outputMust be in range of +/-32,768.0Power PMAC will copy to output or use for commutationRoutine must accept a “MotorData” pointer as arg

11、umentPower PMAC will automatically pass pointer to present motors structurePermits same algorithm to be used unchanged for different motorsProvides access to several useful automatically computed floating-point valuesDesPos: Net desired position (trajectory + master)ActPos: Net actual position (incl

12、uding corrections)PosError: Following errorDesVel: Net desired velocityActVel: Net actual velocityC User-Written Servo Routines (cont.)Declare in form: “double MyServoAlg(struct MotorData *Mptr)”IDE creates declaration automatically from user-entered routine nameUser IDE Project Manager to tell whic

13、h motor(s) use this routineIn Solution Explorer, right-click on “Realtime Routines” under “C Language”Select “User Servo Setup” to get window to assign routines to motorsSets Motorx.Ctrl to UserAlgo.ServoCtrlAddriMultiple-motor servo algorithms can be implementedPermits sophisticated handling of dyn

14、amic cross-coupling effectsAlgorithm to be executed for lowest-numbered of consecutively-numbered motorsSet Motorx.ExtraMotors to number of additional motors handled hereCan access elements for additional motors in two ways:Relative addressing: Mptr2 = Mptr + 1Absolute addressing: pshm-Motor7Example

15、 User-Written Servo RoutineVery simple PID control algorithmUses Delta Tau-defined gain elements Kp, Kvfb, Kidouble user_pid_ctrl(struct MotorData *Mptr) double ctrl_effort; if (Mptr-ClosedLoop) / Servo active in closed loop? ctrl_effort = Mptr-Servo.Kp * Mptr-PosError - Mptr-Servo.Kvfb * Mptr-ActVe

16、l; / PD terms Mptr-Servo.Integrator += Mptr-PosError * Mptr-Servo.Ki;/ I term ctrl_effort += Mptr-Servo.Integrator;/ Combine return ctrl_effort;/ Return value for automatic handling else / Open loop mode Mptr-Servo.Integrator = 0.0;/ Clear integrator return 0.0;/ Zero output C User-Written Phase Rou

17、tinesEach phase update period, every motor with PhaseCtrl 0 calls its specified phase routine (built-in or user-written) as functionEach motor can have its own routineCan provide own name(s) for user-written routine(s)Routine must accept a “MotorData” pointer as argumentPower PMAC will automatically

18、 pass pointer to present motors structurePermits same algorithm to be used unchanged for different motorsCan use saved setup elements as for standard algorithmMust directly access I/O registersNo automatic pre/post-processing as for servoMust explicitly convert between fixed-point I/O and ( mended)

19、floating-point computationsHave access to Power PMACs floating-point math library, even though executing in the real-time kernelC User-Written Phase Routines (cont.)Must be declared in form: “void MyPhaseAlg(struct MotorData *Mptr)”IDE creates declaration automatically from user-entered routine name

20、Routine must write command values directly to output registersCan use address set by Motorx.pDac, as built-in routine does, e.g.:Mptr-pDac0 = PhaseACmd;Mptr-pDac1 = PhaseBCmd;User IDE Project Manager to tell which motor(s) use this routineIn Solution Explorer, right-click on “Realtime Routines” unde

21、r “C Language”Select “User Servo Setup” to get window to assign routines to motorsExample User-Written Phase RoutineSimple sine output commutation routine:void user_phase(struct MotorData *Mptr) int PresentEnc, PhaseTableOffset; float *SineTable; double DeltaEnc, PhasePos, IqVolts, IaVolts, IbVolts;

22、 PresentEnc = *Mptr-pPhaseEnc;/ Read new rotor position DeltaEnc = (double) (PresentEnc - Mptr-PrevPhaseEnc);/ Compute change and convert to floating-point Mptr-PrevPhaseEnc = PresentEnc;/ Store new rotor position for next cycle PhasePos = Mptr-PhasePos + Mptr-PhasePosSf * DeltaEnc;/ Scale change to

23、 sine table increments and accumulate if (PhasePos = 2048.0) PhasePos -= 2048.0;/ Positive rollover? PhaseTableOffset = (int) PhasePos;/ Table entry index Mptr-PhasePos = PhasePos;/ Store in structure for next cycle IqVolts = Mptr-IqCmd;/ Get torque (quadrature) command from servo output SineTable =

24、 Mptr-pVoltSineTable;/ Start address of lookup table IaVolts = IqVolts * SineTable(PhaseTableOffset + 512) & 2047;/ Compute Phase A command IbVolts = IqVolts * SineTable(PhaseTableOffset + Mptr-PhaseOffset + 512) & 2047;/ Compute Phase B command Mptr-pDac0 = (int) (IaVolts * 65536);/ Scale, fix, and

25、 output Phase A Mptr-pDac1 = (int) (IbVolts * 65536);/ Scale, fix, and output Phase BUsing Matlab/SimulinkTM for Servo DesignDesign algorithm graphically in SimulinkSimulate performance with plant model and excitation blockUse “scopes” to analysze performanceDebug and refine until ready to testUsing

26、 Matlab/SimulinkTM for Servo Design (cont.)Replace excitation block(s) and plant model with provided Power PMAC I/O blocks(One-time) installation of “DELTATAU PPMAC Library” in Simulink Library Browser(One-time) load of preset “Configuration Parameters”Invoke Real-Time WorkshopTM “Build Model” actio

27、nBring resulting “.c” and “.h” files into IDE, compile, and downloadSelecting User-Written Phase and ServoReal-Time Interrupt C PLC RoutineEach real-time interrupt (Sys.RtIntPeriod+1 servo interrupts), Power PMAC calls “realtimeinterrupt_plcc” routine if UserAlgo.RtiCplc = 1Note that if tasks from p

28、revious RTI are not finished, can “skip a beat”Routine must be in file rticplc.c in folder rticplc under CPLCs and C Language in projectRoutine must be declared as “void realtimeinterrupt_plcc()”Do not put within indefinite loop Power PMAC causes repeated execution by repeated callsUse a “sleep” fun

29、ction instead to suspendBackground C PLC RoutinesAfter each scan of one background Script PLC, Power PMAC calls each background C PLC routine n as function if its UserAlgo.BgCplcn = 1Up to 32 background C PLC routines (n = 0 to 31)Routine for C PLC n must be in file bgcplcnn.c in folder bgcplcnn und

30、er CPLCs and C Language in projectEach routine must be declared as “void user_plcc()” (routines are distinguished by file name and folder)These background C PLC routines are equivalent to background compiled PLC programs in Turbo PMACNext background Script PLC will not run until C PLCs are finished,

31、 or 100 sec later, whichever is lessDo not put within indefinite loop Power PMAC causes repeated execution by repeated callsUse a “sleep” function instead to suspendExample C PLC RoutineSample program to alternate outputs on UMAC I/O Card#include #include #include #define IoCard0Out0_7*(piom + 0 xA0000C/4)#define IoCard0Out8_15*(piom + 0 xA00010/4)#define IoCard0Out1