Siemens SINUMERIK 840Di Function Manual page 354

Detailed Description
2.3 Travel to fixed stop with analog drives
Depending on the machine parameter:
MD37060 FIXED_STOP_ACKN_MASK
the NC waits for the PLC to acknowledge by resetting IS
"Activate travel to fixed stop" (DB31, ... DBX3.1)
and then the block change is performed.
Deselection
The NC detects that the function has been deselected on the basis of commandFXS[x]=0
and specifies a speed or current setpoint of "0", i.e. zero clamping torque.
The NC then resets IS "Activate travel to fixed stop" (DB31, ... DBX62.4) and "Fixed stop
reached" (DB31, ... DBX62.5).
If current-controlled operation is activated, the PLC must first switch on the current limitation
(terminal 96) and switch the drive over to speed-controlled operation (terminal 22) (a speed
setpoint of "0" is applied by NC).
Then current limitation must then be deactivated (terminal 96).
Depending on the machine parameter:
MD37060 FIXED_STOP_ACKN_MASK
the NC waits for the PLC to acknowledge by resetting IS
"Activate travel to fixed stop" (DB31, ... DBX3.1) and/or
"Acknowledge fixed stop reached" (DB31, ... DBX1.1).
The axis then switches over to position control mode (follow-up mode is terminated) and
synchronization with the new actual position takes place.
The programmed travel motion is then executed.
A block change is executed after the target position has been reached.
2.3.2 SIMODRIVE 611 analog (FDD)
Fixed clamping torque
A fixed clamping torque is implemented by entering a fixed torque limitation in a free gear
stage in the drive actuator (setting parameter 039). When the "Travel to fixed stop function"
is selected, the PLC switches over to the unassigned gear stage of the drive actuator, thus
activating the torque limitation.
Setpoints must be injected via terminals 56/14.
Programmable clamping torque
In this case, the PLC switches the drive actuator from speed-controlled into torque-controlled
operation after the fixed stop is reached. The NC can therefore input a variable clamping
torque.
Setpoints must be injected via terminals 56/14.
References:
/IAA/ Installation and start-up guide SIMODRIVE 611 analog system
2-30
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0
Travel to Fixed Stop (F1)