Limit Switch - Siemens SINAMICS S120 Manual

3 DCC Blocks
SINAMICS
parameter
number
r21883 SpeedSetpoint_
rOut_SpeedSetpoint
3.7

Limit Switch

Symbol
p21840 boEnableEndLimitSwitch
p21841 boEndLimitSwitch_dirPositive
p21842 boEndLimitSwitch_dirNegative
p21843
boEnablePreLimitSwitch
p21844 boPreLimitSwitch_dirPositive
p21845 boPreLimitSwitch_dirNegative
Brief description
The LimitSwitch block relies on the logic of the existing SIMOCRANE Drive-Based
Technology DCC block PreLimitSwitch [Reference page number in DBT Manual]
and adds the functionality of an electronically programmable pre and end limit
switch.
Mode of operation
The user can enable either the end limit switch, pre-limit switch, or both. For
prelimit, the signal from the actual limit switch is parameterized in p21844
(boPreLimitSwitch_dirPositive) for the positive direction, and in p21845
(boPreLimitSwitch_dirNegative) for the negative direction. This limit switch function
is active low, meaning, when not tripped, the limit switches should have a high
signal here. When the limit switch is tripped, the signal goes low, triggering the
prelimit speed parameterized in the drive object containing the CraneDBT, p22057
(PreLimitSwitch_rLimit4 (%)). For example, if p22057 (PreLimitSwitch_rLimit4 (%))
is set to 10 %, and the direction of motion is positive, and the speed is 100%, once
the pre-limit switch set in p21844 (boPreLimitSwitch_dirPositive) is tripped (signal
goes from high to low), the drive will ramp down from 100% to 10% speed. But,
once direction is reversed (going in the negative direction), 100% speed is again
possible.
For end limit, the signal from the actual limit switch is parameterized in p21841
(boEndLimitSwitch_dirPositive) for the positive direction, and in p21842
(boEndLimitSwitch_dirNegative) for the negative direction. As described above this
limit switch function is active low. For example, if the direction of motion is
negative, and the end limit set in p21842 (boEndLimitSwitch_dirNegative) is tripped
(signal goes from high to low), the drive will ramp down to 0% speed. But, once
direction is reversed (going in positive direction), 100% speed is again possible.
NOTE For the LimitSwitch function (from ExtendedCraneDCC) to work PreLimitSwitch
(from CraneDCC) must be configured as described below in the connections
table.
Extended Crane Drive-Based Technology AC
Extended Crane Drive-Based Technology SINAMICS S120
DCC Add-On Description 109767457,
Name Connection
type
OUT
LimitSwitch
V1.2, 09/2019
Default Data
assignment type
0 REAL
boOut_TravelCommand_MasterSwitch
boOut_ActivatePreLimitSwitch (p22053)
Meaning
Effective speed setpoint
r21850
r21851
28