ElmoMC SimplIQ Software Manual User Manual
Page 196
SimplIQ
Software Manual
MAN-SIMSW (Ver. 1.4)
13-1
Chapter 13: Limits, Protections, Faults
and Diagnosis
This chapter describes the limits and protections implemented by
SimplIQ
drives. Limits
are software restrictions that prevent
SimplIQ
drives from running into dangerous
situations. For example:
Limits set for the torque command prevent the motor or
SimplIQ
drive from burning.
Reaction to limit switches stops the motor before it accidentally hits something out of
its expected motion range.
Protections prevent the motor from starting, or shut down an active motor due to
abnormal situations. For example:
Bad or inconsistent setup data prevents the motor from starting.
An unexpectedly high motor current can endanger the
SimplIQ
drive and the motor.
Such a high current is abnormal because the command to the current (torque)
amplifier is limited. If the current controller seems to be functioning poorly, the drive
is immediately shut down.
The drive is too hot.
When the drive shuts down due to a protection, the motor continues to run on its own
inertia unless brakes are used (see
section
). In order to avoid spurious motor
shutdowns, always:
Leave enough space between the limits and the protection. For example, HL[2]
specifies the over-speed limit. A protection is activated when VX > HL[2]. VH[2]
specifies the legal command to the speed controller. Speed commands over VH[2] are
clipped to VH[2]. The protection HL[2] must be greater than the limit VL[2].
Moreover, the distance HL[2] -VH[2] must leave enough space for the expected speed
overshoot.
When safety is a concern, always use brakes.
SimplIQ
drives can program one of their
digital outputs to activate a brake immediately upon motor shutdown.
If an exception stops the motor or prevents the motor from starting, the
SimplIQ
drive, in
most cases, can identify the cause of the event. If a real-time exception reaction is desired,
a #@AUTO_ER routine can be added to the user program (see
).
The following commands are used with limits and protections:
Command Description
BP[N] Brake
parameters.
CD
Dumps the process status of the
SimplIQ
drive and reports database
inconsistencies.
CL[N[
Continuous current limit and “Motor not moving” protection.
EC
Error code describing why previous command returned an error.