Delta RMC151 - Manual (Page 96)

RMC70/150 and RMCTools User Manual
If the halt was caused by an Auto Stop, you should first make sure the error condition
that caused it has been resolved before continuing. Once it has been fixed, you can clear
the External Halt status bit by issuing the Clear Faults (4) command. Issuing a valid
motion command will also clear the External Halt status bit, if the underlying error
condition has gone away.
3.4.3. Closed Loop Halt
The Closed Loop Halt is one of the four types of RMC Halts. Use the Closed Loop Halt to halt
the axis while remaining in closed loop control.
Tip:
The Halts do more than just stop the axis. If you simply wish to stop the motion in closed loop
control, use the Stop (Closed Loop) (6) command instead. If you wish to stop the motion in
open loop control, use the Stop (Open Loop) (22) or Open Loop Rate (10) commands.
When a Closed Loop Halt occurs, it takes the following steps:
• The axis stays in closed loop and stops the axis at the rate specified by the Closed
Loop Halt Deceleration axis parameter. If the axis is in Open Loop when this halt
occurs, this halt will start an Open Loop Halt instead.
See the Stopping Details section below for details on how the stop behaves for
various control modes.
Note:
It is the Target Velocity that is ramped down. If the Actual Position is lagging behind
the Target Position, it will not stop until it reaches the Target Position. If you need the
Actual Position to stop immediately, use an Open Loop Halt or Stop (Open Loop) (22)
command instead.
Note:
The deceleration specified by the Closed Loop Halt Deceleration is the average
deceleration. The instantaneous deceleration may exceed this value.
Note:
The Command Position is not affected by a Closed Loop Halt.
• The Halted status bit is set and the axis is said to be in the halted state.
• If the axis is part of a Halt Group, it starts a Closed Loop Halt on all axes in the group.
Pressure/Force Control
The Closed Loop Halt will keep the axis in pressure or force control, and will stop the
target.
Pressure/Force Limit
The Closed Loop Halt will keep the axis in pressure or force limit, and will not stop the
target.
Stopping Details
This command ramps the current velocity or rate to zero in closed loop. The behavior of
this command depends on the type of axis control:
• Position PID
The velocity will ramp down from the current velocity to zero at the rate specified by
the Closed Loop Halt Deceleration parameter, while remaining in position control.
• Position I-PD
If the last motion command was Move Absolute (I-PD) (28) or Move Relative (I-PD)
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