Lenze 931W - Manual (Page 64)

Software implementation and parameter setting
Reference menu
Reference type
5

64 HB 13.0001-EN 3.0
ƒ During the reference run, the limit switches can additionally be evaluated. This is
recommended, as in many applications at the start of referencing it is not known in
which direction the reference switch is positioned. For activating the evaluation of
the limit switches, the ”Software limit switch” function on the ”System” tab has to
be selected.
– With software limit switch: limit switches are also evaluated
– Without software limit switch: limit switches are not evaluated
If a limit switch is reached in the case of an active monitoring process of the limits switches
during a reference run before the reference switch has been recognised, the reference
speed is reversed, and the search for the reference switch is continued in the opposite
direction.
If the software limit switches are used, the entered limit values (left / right) are irrelevant.
Solely the numerical values have to plausible in themselves (e.g. left limit switch < right
limit switch at positive clockwise direction of rotation).
If no limit switches are evaluated, the drive is traversed at the set reference speed if the
drive is not positioned in the area of the reference switch (see Fig. 4 example 1 and
example 2) at the start of the reference run. If the drive is positioned in the area of the
reference switch, referencing at first is carried out at negatived reference speed until the
area of the reference switch is left. Then the edge of the reference switch is traversed at the
reference speed selected, and the home position is set.
If the limit switches are evaluated, the reference run always is started at negatived
reference speed. It is only reversed when a reference switch is left (see Fig. 4 example 4) or
when a limit switch is reached (see Fig. 4 example 3). This procedure ensures that the drive
is braked and has to be accelerated in the opposite direction only once during a reference
run.
The reference run to a reference switch as well as the above settings is illustrated by means
of examples. They are shown in the Fig. 4.
For example 1, a positively set reference speed is selected, and referencing is carried out to
the edge to the high signal level. The limit switches at first are not evaluated. The drive -
as it is not positioned in the area of the reference switch at the start - traverses at the set
reference speed until the reference switch is recognised via the rising edge of the digital
input. Here, the 0 position is set. Then the drive is stopped. Example 2 shows a similar
process at negative speed.
Inexamples3 and4, thelimit switchesare evaluated.Inbothcases, thedrives aretherefore
started at the negatived reference speed. In example 4, the reference switch is recognised
and traversed. After the reference switch has been traversed, the drive is stopped and
afterwards accelerated to the defined reference speed. When the area of the reference
switch is re-entered, the 0 position is set, and afterwards the drive is stopped. In the case
of example 3, first the limit switch is reached. Here the drive reverses its direction of
rotation and traverses at the defined reference speed until the rising edge of the reference
switch is recognised.