User Manual

Motion control is easy
10.6 Operation of motion control for S7-1200
Easy Book
246 Manual, 03/2014, A5E02486774-AF
WARNING
Risks with changes to filter time for digital input channel
If the filter time for a digital input channel is changed from a previous setting, a new "0"
level input value may need to be presented for up to 20.0 ms accumulated duration before
the filter becomes fully responsive to new inputs. During this time, short "0" pulse events of
duration less than 20.0 ms may not be detected or counted.
This changing of filter times can result in unexpected machine or process operation, which
may cause death or serious injury to personnel, and/or damage to equipment.
To ensure that a new filter time goes immediately into effect, a power cycle of the CPU
must be applied.
Software limit switches
Software limit switches limit the "working range" of the axis. They should fall inside the
hardware limit switches relative to the travel range. Because the positions of the software
limit switches can be set flexibly, the working range of the axis can be restricted on an
individual basis depending on the current traversing profile. In contrast to hardware limit
switches, software limit switches are implemented exclusively by means of the software and
do not require their own switching elements.
If software limit switches are activated, an active motion is stopped at the position of the
software limit switch. The axis is braked at the configured deceleration. The following
diagram presents the behavior of the axis until it reaches the software limit switches.
①
The axis brakes to a standstill at the configured deceleration.
A
[Velocity]
B
Working range
C
Distance
D
Lower software limit switch
E
Upper software limit switch