Festo Электроцилиндр - Manual (Page 24)

2 Overview
24 Festo – GDCP-CMMO-ST-EA-SY-EN – 1301a – English
In all cases the reference point is either at the switch-off point or on the following index
pulse (dependent on the homing method selected).
For the last case: If a switch is not found in the reverse direction before a stop is
reached, the homing run is aborted with an error message.
If no switch is found at all and no stop is available, the homing run will never be com-
pleted, i.e. the drive will run continuously at the parameterised search speed.
For a homing run with index search: If no index pulse is found during the index search
over more than one motor rotation, the homing run is aborted with an error message.
For open-loop operation ( section 2.2.4):
The homing run in open-loop operation is generally executed in the same way as in closed-loop opera-
tion. However, the following special features apply:
– Stops are not detected
– An index search is not possible
– If a switch has not been found after a certain period of time, the homing run is aborted with an
error message. This timeout time can be set in FCT (“Homing” panel, “Settings” tab). The drive
therefore must always be positioned before the start of a homing run so that it can find the switch.
2.7.4 Homing method “current position”
The current position becomes the reference position. Apart from an optional movement to zero
( section 2.7.6), no positioning motion is executed.
In open-loop operation ( section 2.2.4) without a reference switch, this is the only possible homing
method.
2.7.5 Automatic homing (valve profile)
An “automatic homing run“ can be parameterised in the valve profile (FCT: “Homing” panel,
“Settings” tab).
This is executed automatically if the drive is not referenced at the start of a position record. The
started position record is then executed.
The automatic homing run is aborted if the position record input is reset again before the automatic
homing run has been executed completely.