5.5 Operation Sequence when OT (Overtravel Limit Switch) Signal is Input
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5.5
Operation Sequence when OT (Overtravel Limit Switch) Signal is Input
When an OT signal is input, the SERVOPACK prohibits the motor from rotating in the way spec-
ified in parameter Pn001. The motor continues to be controlled by the SERVOPACK while its
rotation is prohibited.
When an OT signal is input, use the following procedure to process the OT signal.
Procedure
Operation
1
Monitor OT signals. When an OT signal is input, send an appropriate stop command:
While an interpolation command (INTERPOLATE) is being executed: Continues execution of
the interpolation command while stopping updating of the interpolation position. Or, sends an
SMON command.
While a move command (such as POSING) other than interpolation commands is being exe-
cuted: sets CMD_CANCEL = 1.
2
Check the output completion flag DEN. If DEN = 1, the SERVOPACK completed the OT pro-
cessing.
At the same time, check the flag ZSPD. If ZSPD = 1, the motor is completely stopped. Keep
the command used in procedure 1 active until both of the above flags are set to 1.
3
Read out the current reference position (CPOS) and use it as the start position for retraction
processing.
4
Use a move command such as POSING or INTERPOLATE for retraction processing. Continue
to use this command until the retraction is finished. If the move command ends without finish-
ing the retraction, restart the move command continuously from the last target position.
•
When an OT signal is input during execution of a motion command such as ZRET, EX_FEED or
EX_POSING, the execution of the command will be cancelled.
•
During the overtravel state (P-OT = 1 or N-OT = 1), the servomotor is not positioned to the tar-
get position specified by the host controller. Check the feedback position (APOS) to confirm
that the axis is stopped at a safe position.
If the state of an OT signal varies over a short time (in a pulsing manner for example), the host
controller may not be able to monitor the variation of the OT signal properly. Take due care about
the selection of limit switches and their mounting and wiring to avoid chattering of OT signals and
malfunctioning.
Note
Important
