Siemens SINUMERIK 840Di Function Manual page 94

Detailed Description
2.3 Monitoring of static limits
2.3 Monitoring of static limits
2.3
2.3.1 Overview of the limit switch monitoring
Overview of possible limit switch monitoring functions:
Fig. 2-8
2.3.2 Hardware limit switches
Function
A hardware limit switch is normally installed at the end of the traversing range of a machine
axis. It serves to protect against accidental overtravelling of the maximum traversing range of
the machine axis while the machine axis is not yet referenced.
If the hardware limit switch is triggered, the PLC user program created by the machine
manufacturer sets the corresponding interface signal:
DB31, ... DBX12.0 / 12.1 = 1 (hardware limit switch minus / plus)
2-22
Travel limits
Axis Monitoring, Protection Zones (A3)
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0