Limitations And Constraints; Precedence Of Function-Specific Acceleration; Axis Container - Siemens SINUMERIK 840D sl Function Manual

TE9: Axis pair collision protection

21.4 Limitations and constraints

Bit n → (n+1)th machine axis, with n = 0, 1, 2, ...
Bit n
21.4 Limitations and constraints
21.4.1

Precedence of function-specific acceleration

The function only uses the function-specific acceleration of the machine axes MD63514
$MA_CC_PROTECT_ACCEL (Page 750) to calculate the time at which the axis should be
braked. This means that the protection function does not take the actual acceleration of the
machine axis in the channel into account.
Note
Path reference
If machine axes being monitored by the function are traversed by a channel with a path
reference to other axes, this path reference is lost as soon as the protection function causes
the axis grouping to decelerate. The machine axes being monitored by the function are braked
using their function-specific acceleration values from machine data item MD63514
$MA_CC_PROTECT_ACCEL. The remaining axes in the axis grouping are decelerated using
the current path acceleration value of the channel.
21.4.2

Axis container

If the assignment of the machine axes to be monitored changes dynamically during the course
of a machining process – for example when using axis containers – the function must be
deactivated, its parameters reassigned, and then reactivated prior to the change (e.g. axis
container rotation) being made.
Example
The protection function is to monitor logical machine axes 1 and 13. These relate to slots 1
and 2 of axis container CT1. The associated real machine axes are AX1 and AX13.
In an axis container rotation, the axis container makes a transition by one step, which causes
the real machine axes to be changed.
Machine axis AX13 is retracted in the positive direction of travel. Machine axis AX1 is retracted
in the negative direction of travel.
752
Meaning
0 Machine axis (n+1) is not braked
1 Machine axis (n+1) is braked
Function Manual, 01/2015, 6FC5397-2BP40-5BA2
Special functions