Trapezoidal Position Profiles - Related TML Instructions and Data

Trapezoidal Position Profiles – Related TML Instructions and Data

Parameters

CPOS	Command position – desired position (absolute or relative) for the load. Measured in position units.

CSPD	Command speed – desired slew speed for the load. The command speed can have only positive values. Measured in speed units.

CACC	Command acceleration – desired acceleration / deceleration for the load. The command acceleration can have only positive values. Measured in acceleration units

ACR Auxiliary Control Register – includes several TML programming options

Variables

TPOS	Target load position – position reference computed by the reference generator at each slow loop sampling period. Measured in position units

TSPD	Target load speed – speed reference computed by the reference generator at each slow loop sampling period. Measured in speed units

TACC	Target load acceleration – acceleration/deceleration reference computed by the reference generator at each slow loop sampling period. Measured in acceleration units

APOS_LD Actual load position. Measured in position units. Alternate name: APOS

ASPD_LD Actual load speed – measured in speed units

APOS_MT Actual motor position. Measured in motor position units

ASPD_MT

Actual motor speed. Measured in motor speed units Alternate name: ASPD

Instructions

CPR Command position is relative

CPA Command position is absolute

MODE PP Set position profile mode

TUM1	Target Update Mode 1 (TUM1). Generates new trajectory starting from the actual values of position and speed reference (i.e. don’t update the reference values with load/motor position and speed)

TUM0	Target Update Mode 0 (TUM0). Generates new trajectory starting from the actual values of load/motor position and speed (i.e. update the reference values with load/motor position and speed)

UPD Update motion parameters and start new motion mode

STOP Stop the motion

SRB Set/reset bits from a TML data

Remarks:

•	CSPD and CACC must be positive. Negative values are taken in modulus

•	The difference between CPOS and TPOS values in modulus must be maximum 231-1.

•	The sum between CSPD and CACC values must be maximum 32767.99998 (0x7FFF.FFFF) i.e. the maximum value for fixed number

•	Once a position profile is started, you can find when the motion is completed, by setting an event on motion complete and waiting until this event occurs.

•

In order to activate the TUM1 mode, execute the TML instruction TUM1 AFTER the MODE PP command and BEFORE the UPD command. When MODE PP is executed, it automatically sets TUM0 mode. However, as the new motion mode becomes effective only after the UPD command, a TUM1 command will overwrite the TUM0 mode

•	Under TUM0 mode, at the UPD command TPOS=APOS_LD and TSPD=ASPD_LD. In open loop control of steppers, TUM0 is ignored as there is no position and/or speed feedback

•	In setup configurations where there is no transmission ratio between the motor and the load, it is supposed that these are directly connected. In these cases: APOS_MT=APOS_LD and ASPD_MT=ASPD_LD

Programming Example

// Position profile. Position feedback: 500 lines incremental

// encoder (2000 counts/rev)

CACC = 0.3183; //acceleration rate = 1000[rad/s^2]

CSPD = 33.3333; //slew speed = 1000[rpm]

CPOS = 6000; //position command = 3[rot]

CPR; //position command is relative

SRB ACR 0xFFFF, 0x800; // and additive

MODE PP; // set trapezoidal position profile mode

TUM1; //set Target Update Mode 1

UPD; //execute immediate

!MC; WAIT!; //wait for completion