Siemens Sinumerik 840D sl Function Manual page 803

10/15
Setpoint changeover and Safety Integrated
In conjunction with the setpoint changeover, the SI functionality is only supported
with a restricted scope. At each setpoint changeover, the absolute position refer-
ence is lost. This means that only SI functions can be sensibly and practically used
that do not require absolute position information. These functions include SBH, SH,
SG, SBR, Stops and SPL.
Note
SE and SN are not supported.
The SI monitoring functions are only calculated in the axis configured for this -- not
taking into account existing drive checking functions. This means that only this SI
machine axis detects SI fault/error states. The associated alarm responses are
automatically effective for all of the axes involved in the setpoint changeover.
MD36901 SAFE_FUNCTION_ENABLE may only be activated in the last machine
axis configured for the setpoint changeover. This fixed assignment is kept over all
setpoint changeover operations.
In conjunction with Safety Integrated, all of the axes, involved in the setpoint
changeover, must be configured in the same channel.
If the SI monitoring is also to be effective when traversing/moving non--SI axes,
then it is not permissible that the SI axis is parked during this time.
An axis with the existing drive checking function DB3x.DBX96.5=1 must be parked
at the same time as an SI axis. This means that the axis SI monitoring functions
are de--activated synchronously in the drive and in the SI axis. Parking the axis --
must always be selected for both axes.
The "parking" operating state can only be exited using the axis with the drive
checking function.
As a result of the mechanical changeover, the motor encoder (G1) – monitored
using SI – is moved from several axes one after the other. In order to be able to
determine the correct speed on the load side, the existing gearbox ratios of the
axes involved must be sensibly emulated (mapped) in the 8 elements of MD36921,
36922 of the SI axis and the drive p9521, p9522.
In order that the correct gearbox ratio factor becomes effective in the SI monitoring
function, the PLC must select the associated SI gearbox ratio and change over the
setpoint at the same time.
The SGEs to change over the gearbox stage must be safety--related and therefore
be able to be controlled through 2 channels. Channel 1 should evaluate the feed-
back signals from the gearboxes, channel 2 should evaluate the feedback from the
setpoint changeover DB3x.DBX96.5 "Check of drive accepted". It is not permis-
sible to use a 1--channel signal source to control the SGEs.
© Siemens AG 2015 All Rights Reserved
SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) - - 10.2015 Edition
Interaction with other functions
11.2 Setpoint exchange
11-803