Configuration - Position Monitoring - Siemens SIMATIC S7-1500 Function Manual

6.6.4.2

Configuration - Position monitoring

Configure the hardware and software limit switches of the axis in the "Position monitoring"
configuration window.
Enable HW limit switches
The check box activates the function of the negative and positive hardware limit switches.
The negative hardware limit switch is located on the side in the negative direction of travel,
and the positive hardware limit switch on the side in the positive direction of travel.
With enabled hardware limit switches, the drive is disabled when the hardware limit switch is
approached or overshot. The drive brakes with the braking ramp configured in the drive.
Exception: If a hardware limit switch is overshot during an active home position approach
with activated direction reversal at the hardware limit switch, then the axis stops with the
configured maximum deceleration, and continues the home position approach in the
opposite direction.
Note
Only use hardware limit switches that remain permanently switched after the approach. This
switch state may only be canceled after the return into the permitted traversing range.
The digital inputs of the hardware limit switch are evaluated by default in cyclical data
exchange. In the settings for the input module under "I/O addresses", select the entry
"MC-Servo" for "Organization block" and the entry "PIP OB servo" for "Process image" if the
hardware limit switches are to be evaluated in the position control cycle of the drive.
Negative / positive HW limit switch input
In these fields, select the PLC tags of the digital input for the negative and positive HW limit
switches.
In order to be able to select an input, a digital input module must have been added in the
device configuration, and the PLC tag name for the digital input must be defined.
During installation of hardware limit switches, attention must be paid to the filter times of the
digital inputs
Based on the time for a servo clock cycle and the filter time of the digital inputs, the
resulting delay times must be taken into account.
The filter time is configurable in individual digital input modules in the device configuration.
The digital inputs are set to a filter time of 6.4 ms by default. If these are used as hardware
limit switches, undesired decelerations may occur. If this occurs, reduce the filter time for
the relevant digital inputs.
The filter time can be set under "Input filter" in the device configuration of the digital inputs.
S7-1500 Motion Control V13 Update 3
Function Manual, 07/2014, A5E03879256-AC
6.6 Configuring the positioning axis/synchronous axis technology object
CAUTION
Configuring
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