Index - Siemens Sinumerik 840D sl Function Manual

Basics on the safety functions integrated in the system/drive
5.4 Actual value conditioning
8 different gearbox stage pairs for NCK/drive can be defined. For this definition,
there is no special function for an index value -- e.g. interdependency on the
operating mode of the spindle. These 8 pairs must be parameterized and selec-
ted depending on the encoder configuration.
S As a result of the gearbox stage changeover, the encoder evaluation for the
safety--related actual values change. Ideally, the gearbox stage for Safety Inte-
grated is changed--over at standstill. However, this is generally not in--line with
what is required in practice. This means that the actual value offset when
changing--over the gearbox stage (e.g. using oscillation) may not be greater
than the already mentioned actual value tolerance window (MD36942 / p9542).
S If, for the axis with control gear, position--dependent monitoring functions are
activated -- such as SE or SN -- the user agreement (assuming that it was pre-
viously set) is withdrawn when changing--over the gearbox ratio and the SGA
"axis safely referenced" is set to 0. When the gearbox stage is changed from
the PLC and/or by selecting a new ratio, a new gearbox ratio is detected using
the appropriate SGEs.
S After the gearbox stage has been selected, the spindle must be re--synchroni-
zed. When resynchronizing the spindle, the two safety--related actual values
(NCK and drive) are re--initialized with the newly synchronized actual value.
A possible difference that was previously present between the two safety--rela-
ted actual values is therefore corrected.
S In order to be able to re--use the SN or SE function after the gearbox ratio has
been selected (changed), the user must bring the spindle into the state "axis
safely referenced" -- the user agreement must be re--issued.
S For 2--encoder systems, the gearbox ratio does not have to be selected in a
safety--related fashion and can be implemented through one channel. On the
other hand, for a 1--encoder system, the ratio selection must implemented using
safety--related technology -- i.e. using two channels.
Warning
!
When a new stage is selected for a control gear (the ratio changed), an axis is
parked or the mounting situation is modified (encoder and motor replaced), this
means that the load and encoder have been decoupled. The NC and drive cannot
detect this. The state "axis safety referenced" is no longer applicable.
The user is responsible in bringing the axis back into the "axis safely referenced"
state if the functions "safe software limit switch" or "safe cams" are used.
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SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) - - 10.2015 Edition
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