Siemens SINUMERIK 840D Function Manual page 99

Actions when deselecting the function
When deselecting the function, the following actions are executed:
● A preprocessing stop is initiated (STOPRE)
● The NC/PLC interface signals are reset
– DB31, ... DBX62.4 = 0 (activate travel to fixed stop)
– DB31, ... DBX62.5 = 0 (fixed stop reached)
● Depending on the machine data, the system waits for acknowledgment from the PLC user
program:
– MD37060 $MA_FIXED_STOP_ACKN_MASK
– DB31, ... DBX3.1 == 0 (enable travel to fixed stop)
– DB31, ... DBX1.1 == 0 (acknowledge fixed stop reached)
● Exiting the follow-up mode
● Axis resumes closed-loop position control
Pulse enable
The pulse enable or pulse inhibit can be canceled via:
● Drive: Via terminal EP (enable pulses)
● NC/PLC interface signal: DB31, ... DBX21.7 ("pulse enable")
The behavior at the fixed stop can be set via the following machine data:
MD37002 $MA_FIXED_STOP_CONTROL, bit 0 and bit 1 (sequence control for traversing to fix
stop)
Bit
0
1
Special case: Deleting the pulse enable during deselection
If, during deselection, the function in state: "Waiting for PLC acknowledgements" the pulse
enable is deleted, the torque limit is reduced to 0. In this phase, if pulse enable is set again
torque is no longer established in the drive. Once the deselection has been completed the axis
can be traversed normally again.
Axes and spindles
Function Manual, 06/2019, A5E47437747B AA
Val‐ Meaning
ue
Behavior for pulseinhibit at the fixed stop
0 "Travel to fixed stop" is aborted
1 "Travel to fixed stop" is interrupted, i.e. the drive is without power.
Behavior for pulseenable at the fixed stop
0 The torque is injected suddenly.
1 The torque is linearly ramped-up over the time specified in the machine data:
MD37012 $MA_FIXED_STOP_TORQUE_RAMP_TIME
F1: Travel to fixed stop
3.2 Detailed description
99