Use Of Handwheels In Automatic Mode; Handwheel Override In Automatic Mode; General Functionality - Siemens SINUMERIK 840D Function Manual

17.13

Use of handwheels in automatic mode

17.13.1

Handwheel override in automatic mode

17.13.1.1

General functionality

Function
With this function it is possible to traverse axes or to change their velocities directly with the
handwheel in automatic mode (Automatic, MDA).
The handwheel override is activated in the NC part program using the NC language elements
FD (for path axes) and FDA (for positioning axes) and is non-modal.
With positioning axes, it is possible to activate the handwheel override modally using traverse
command POSA. When the programmed target position is reached, the handwheel override
becomes inactive again.
Additional axes can be traversed simultaneously or using interpolation in the same NC block.
The concurrent-positioning-axes function can also be activated by the PLC user program.
Distinction
Depending on the programmed feedrate, a distinction is made between the following for
handwheel override:
● Path definition
Axis feedrate = 0 (FDA = 0)
● Velocity override
Axis feedrate > 0 (FD or FDA > 0)
The table below shows which axis types can be influenced by the "handwheel override in
automatic mode" function.
Axes that can be influenced by the "handwheel override in automatic mode" function
Axis type
Positioning axis
Concurrent posi‐
tioning axis
Path axis
Axes and spindles
Function Manual, 06/2019, A5E47437747B AA
Velocity override
FDA[AXi] > 0 ;
acts axially
Parameter "Handwheel override active" = 1 and
axis feedrate > 0 from FC18
FD > 0 ;
acts on path velocity
H1: Manual traversing
17.13 Use of handwheels in automatic mode
Path definition
FDA[AXi] = 0
Parameter "Handwheel over‐
ride active" = 1 and axis fee‐
drate = 0 from FC18
Not possible
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