Elmo HARSFEN0602, HARmonica software manual 145, Motion Management

HARSFEN0602ElmoHARmonicaSoftwareManual		PRELIMINARYDRAFT
The speeds in the table	limited to +/- 223	counts/second.
The times in the table	in the range [1,255] msec.

If the position feedback sensor counts modulo, the PVT data must be so that the range of the interpolated data is [-XM...XM-1] (Set YM instead of XM here and in the next sentences if UM=4). Interpolated results in the ranges [-XM...-XM/2-1] or [XM/2...XM-1] will be folded modulo XM to the sensor range of [- XM/2...XM/2-1]. Interpolated points out of the range [-XM...XM-1] will be clipped by the Stop-Manager, refer the section on the "Stop management".

12.1.6.3Motion Management

In the PVT mode, the Amplifier manages a “read pointer” for the PVT table.

When the read pointer is N, the present motion segment starts at the coordinates written at the Nth row of the table, and ends at the coordinates of the (N+1) row4.

When the time period specified by QT[N] elapses, the N segment is done, the Amplifier increments the read pointer to N+1, and reads the N+2 PVT table row to calculate the parameters of the next motion segment.

The user does not have to use the entire PVT table for a given motion.

The use of the PVT table is defined by the following parameters:

Parameter	Use
MP[1]	The lowest valid row of the PVT table
MP[2]	The highest valid row of the PVT table
MP[3]	A bit field.
	Bit 0 is:
	0: Motion is to stop if the read pointer reaches MP[2]
	1: Motion is to continue when the read pointer reaches MP[2]. The next
	row of the table is MP[1].
	Bit 1 is:
	0: PVT motion not expected to terminate. Issue an exception if PVT
	motion terminates.
	1: PVT motion expected to terminate. When all the data in the PVT table
	has been used, exit the PVT mode to the Idle mode without issuing an
	Emergency object.
	Table 12-7 – PVT Motion Parameters

145

The flow chart of the basic PVT mode is depicted below. The flow chart assumes that the commands PV=N;BG; were entered, with 1 N 64 .

4The PVT mode may be cyclical, according to MP[3] – please refer the explanations below. In that case N+1 must be interpreted in the modulo sense.