Siemens SINUMERIK 840D sl Function Manual page 374

Detailed Description
2.3 Travel to fixed stop with analog drives
The torque set in the machine data: MD37070 FIXED_STOP_ANA_TORQUE acts on the
drive MD37070
If the machine data:
MD37060 FIXED_STOP_ACKN_MASK
is set correspondingly, the acknowledgement of the PLC via the NST
("Acknowledge fixed stop reached") (DB31, ... DBX1.1) is awaited and then the requested
clamping torque is transferred from the select block to the drive steplike.
Then a block change is executed. The clamping torque continues to be applied.
Fixed stop is not reached
If the programmed end position is reached, without the "fixed stop reached" status being
detected, then the internal torque limitation set in the machine data:
MD37070 FIXED_STOP_ANA_TORQUE
is cancelled and the NST signal "Activate travel to fixed stop".
(DB31, ... DBX62.4) is reset.
The PLC must then deactivate the current limitation (terminal 96).
Depending on the machine data:
MD37060 FIXED_STOP_ACKN_MASK
the acknowledgement of the PLC is awaited through resetting of the NST
"Enable travel to fixed stop" (DB31, ... DBX3.1) awaited
and then a block change is executed.
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.
Then the NC resets IS "Activate travel to fixed stop" (DB31, ... DBX62.4) and "Fixed stop
reached" (DB31, ... DBX62.5).
If currentcontrolled operation is activated, the PLC must first switch on the current limitation
(terminal 96) and switch the drive over to speedcontrolled 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 data:
MD37060 FIXED_STOP_ACKN_MASK
the acknowledgement of the PLC is awaited through resetting of the NST
"Enable travel to fixed stop" (DB31, ... DBX3.1) and/or
("Acknowledge fixed stop reached") (DB31, ... DBX1.1) is awaited.
The axis then switches over to position control mode (followup 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.
38
Basic logic functions: Travel to fixed stop (F1)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0