ElmoMC SimplIQ Digital Servo Drives-Bell Command Reference - Manual (Page 237)

Chapter 6: The Position Reference
Generator
The position reference signal is generated by the following components
Software reference generator
External position reference generator
Stop manager
The contents of this chapter apply to:
- Closed loop position control (UM=4, UM=5)
- Open loop stepper control (UM=3)
6.1. Software Reference Generator
The SimplIQ drive supports five modes of software referencing:
Idle: motor standing in place
This is the default mode after setting motor on, and after an interpolated motion is
complete.
PTP: point-to-point
The user specifies the position in which the motor is to stand, and the limits subject to
which the trajectory to the target should be designed. The
SimplIQ drive automatically
designs a minimum-time trajectory and executes it.
Jog
The user specifies the speed at which the motor should steadily move and the
acceleration limits to implement towards that speed. The
SimplIQ drive automatically
designs a minimum-time trajectory and executes it.
PT: position/time
The user specifies a set of points to be visited at fixed points of time. The SimplIQ drive
interpolates a third-order polynomial between the user’s points. The speeds at the user
points are selected in order to form a smooth motion trajectory. Using PT, complex
motions are easily designed. PT data may be transferred to the drive online using an
efficient CAN PDO protocol, so that infinite PT motions are possible.
PVT: position/velocity/time
The user specifies a set of motion points, each of which includes a position and the speed
and time at which the position should be visited. The user points are interpolated using
third-order polynomials. PVT mode allows absolute time specification so that several
drives may compose a fully-synchronized motion. PVT data can be transferred to the
drive online using an efficient CAN PDO protocol, so that infinite PVT motions are
possible.
In order to initiate a software motion, its parameters must be initialized and a mode
command issued. The next BG (software, hardware or timed) will start the motion. The
following are the mode commands:
SimplIQ for Steppers Application Note The Position Reference Generator
MAN-STECR (Ver. 1.1)
38