Elmo HARmonica, HARSFEN0602 software manual 158, Parameters of The PT Motion Mode

HARSFEN0602ElmoHARmonicaSoftwareManual PRELIMINARYDRAFT

PT motion must start with initial programming of the PT arrays. First set

MP[1] = First valid line in the PT table MP[2] = Last valid array in the PT table MP[3] = 1 for cyclical mode.

MP[4] = the ration between the length of the PT time interval and the sampling time of the position controller

MP[5] = Number yet unused QP[N] elements when a “PT queue low” emergency object is sent. Set to zero if no “PT queue low” warning is desired.

MP[6]=the write pointer. This is the next position in the QP[N] vector to be written by the CANopen object 0x2002.

Set the QP[N] for at least the first two points in the PT motion. This is since the PT algorithm requires at least two time points to interpolate a motion trajectory. Set at least 3 points if the speed at the second point is to be continuous.

Set (if not already set) UM=4 or UM=5, and MO=1

Set PT=N, where QP[N] and QP[N+1] and preferably QP[N+2] are all programmed to valid values.

Then use the CAN PT/Auto increment command for the rest of the PT motion.

Keep informed how the PT motion advances, either by receiving the read and the write PT table pointers continuously, mapped to a synchronous PDO, or by using the queue low emergency signal to signal the need for more data. The queue low emergency message includes the present location of the read pointer and the write pointer. It is safe to send more PT data PDOs until the write pointer is one location before the read- pointer specified by the queue low emergency message.

The host is well aware to the location of the write pointer, since it can count its own messages. A data message may be, however, rejected since the queue is full, or since a message is lost. In that case, the Amplifier will issue an emergency object to the host. After receiving the emergency object the true location of the write pointer may be unclear. The host may then set MP[6] to the possibly rejected table row and continue the writing from there.

12.1.7.9The Parameters of The PT Motion Mode

The following parameters apply to PT motion

What	How	Comment
Unit Mode (UM)	Unit modes 3,4 or 5 select a
	position mode.
Stop Deceleration (SD)	The rate of deceleration in
	the case where motion is
	killed by queue underflow or
	by an exception.
	SD is also the acceleration to
	catch up with a PT motion
	started with bad initial
	conditions.
Position/ Time (PT)	Set a PT motion command	Special features are available for
		PT using CAN communication
PT table entries: QP[N]	Set values to the PT table
Motion Parameters (MP)	MP[1] = First valid row in	Configure a PT or PVT motion.
	PVT table	MP[6] and MP[5] are for the CAN
	MP[2] = Last valid row in	auto increment mode only.
	PVT table
	MP[3] = Cyclical motion (0
	non-cyclical, 1 cyclical)

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