ElmoMC SimplIQ Software Manual - Manual (Page 200)

SimplIQ Software Manual Limits, Protections, Faults and Diagnosis
MAN-SIMSW (Ver. 1.4)
13-5
In order to avoid spurious motor shutdowns, always:
ƒ
Specify the largest ER[2] that can be tolerated.
ƒ Leave large enough space between VH[2] and HL[2], and between VL[2] and LL[2],
to allow for speed overshoots.
13.3 Position Protection
SimplIQ drives provides two forms of position protections:
ƒ Position-following-error protection (ER[3])
ƒ Out-of-position-range protection (HL[3]/LL[3])
The first protection detects an error of too large a position. The ER[3] parameter specifies
the limit for the position error. If the absolute value of the tracking error PE exceeds
ER[3], the
SimplIQ drive issues the exception MF=0x100 and the motor is shut down
automatically.
The second protection detects a motor position that is out of range. If the position
feedback (PX in UM=4 and PY in UM=5) is greater than HL[3], or less than LL[3], the
SimplIQ drive issues the exception MF=0x400,000 and the motor is shut down
automatically.
Position reference and feedback limits should not be placed too close to position counter
limits because there, the relations “greater than” and “smaller than” are not well defined
(see
section 12.1 ).
ER[3] is limited to the modulo counting range (described fully in the ER[3], XM[N]
and YM[N] command sections in the SimplIQ Command Reference Manual).
The following table lists the effects of the position limits on the different unit modes:
Unit Mode Results
UM=1 No position limiting
UM=2 No position limiting
UM=3 No position limiting
UM=4 Position control by an auxiliary sensor
UM=5 Position control by a main sensor
Table 13-1: Effects of Position Limits on Unit Modes
The position command and feedback limits are illustrated in the following figure.
The drive normally operates in the area marked “Within command and feedback limits.”
However, it may momentarily visit the areas marked “Overshoot area” due to an
overshoot, which is acceptable. If the position feedback reaches the “Abort area” the
drive will issue an out-of-position-range exception and automatically shut down.