Siemens SINUMERIK 840Di Function Manual page 343

Programming FXS in synchronized actions
The function is not available for analog axes (PLC acknowledgment cannot be awaited).
Select FXS[ ]=1:
The following signal interfaces are set:
Message to PLC:
IS "Activate travel to fixed stop" (DB31, ... DBX62.4)
The FXS selection command can only be used in systems with digital drives (VSA, HSA,
HLA).
The following condition must be observed:
MD37060 FIXED_STOP_ACKN_MASK, Bit 0 = 0
Bit 0 = 1 (waiting for PLC acknowledgment) must not be set, otherwise, an interpolator stop
would be required to acknowledge the signal, interrupting the movement.
Deselect FXS[ ]=0:
The following signal interfaces are reset:
Message to PLC:
IS "Activate travel to fixed stop" (DB31, ... DBX62.4)
The machine parameter:
MD37060 FIXED_STOP_ACKN_MASK
must have the value null for signal deselection without motion stop.
Without ramp
The torque limit is changed without taking into account the ramp if:
• FXS is activated with (FXS[]=1), to make sure that the reduction is activated
• The drive needs to be de-energized as quickly as possible in the event of a fault.
Selection of FXS with G64
In the machine parameter:
MD37060 FIXED_STOP_ACKN_MASK
bit 0 must be 0 (do not wait for PLC input signal "travel to fixed stop active"), since the
selection of FXS may not initiate a motion stop.
Modify the torque FXST
The clamping torque can already be modified when approaching the stop.
The torque limit FXST acts in addition to the acceleration limitation with ACC.
Travel to Fixed Stop (F1)
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0
immediately (especially for synchronized actions).
Detailed Description
2.1 General functionality
2-19