Elmo HARmonica, HARSFEN0602 software manual 184, Position Protection

HARSFEN0602ElmoHARmonicaSoftwareManual PRELIMINARYDRAFT

184

	LL[2]
Abort	W ithin speed feedback lim its, out of
	com m and lim its.
Area

VL[2]

Over- shoot

Area	W ithin speed com m and and
	feedback lim its

0

Figure 36: Speed command and feedback limits

HL[2]

Abort

Area

VH[2]

Over- shoot Area

!Remember that when the amplifier shuts down by exception, the motor will continue to run by its own inertia unless brakes are used (refer the section Connecting an external brake).

In order to avoid spurious motor shut downs, always:

-Specify the largest ER[2] you can tolerate

-Leave enough space between VH[2] and HL[2], to allow speed overshoots

-Leave enough space between VL[2] and LL[2], to allow speed overshoots.

14.3Position Protection

The Harmonica provides two forms of position protections.

-Over error protection.

-Out of position range protection.

The first protection detects a too big position error.

The parameter ER[3] specifies the limit for the position error.

If the absolute value of the tracking error PE exceeds ER[3], The Harmonica issues the exception MF=0x100 and the power amplifier is shut down.

The second protection detects that the motor position is out of range. If the position feedback (PX in UM=4, PY in UM=5) is greater than HL[3], or less than LL[3], The Harmonica issues the exception MF=0x400000 and the power amplifier is shut down.

The position reference and feedback limits are inactive if the position counter counts modulo, since then the relations "Greater Than" and "Smaller Than" are not well defined. The table below details the particular cases:

Case	Description
UM=1, nonzero XM	Torque control, limits taken by the main modulo feedback
UM=2, nonzero XM	Speed control by main modulo sensor.
UM=3	No feedback limits since there is no feedback
UM=4, nonzero YM	Position control by an auxiliary modulo sensor.
UM=5, nonzero XM	Position control by an main modulo sensor.

Table 14-2: Cases where feedback limits do not apply