Siemens SINUMERIK 840D sl Function Manual page 157

03.06
Synchronizing cam signals
As a result of system-related actual value differences, the cam signals of the moni-
toring channels can have different states. In order to prevent this, the cam syn-
chronization can be activated. This rounds-off the results of both channels.
The cam SGAs at the input position of the SPL are synchronized if the user has
parameterized this using the function enable.
Cam signal synchronization is enabled using the following machine data / parame-
ters:
for 840D sl:
MD 36901: $MA_SAFE_FUNCTION_ENABLE, bit 7
for SINAMICS S120:
p9501: enables safety functions, bit 7
The cam SGAs including the hysteresis, but without synchronization are displayed
in the service screen and servo trace.
Hysteresis of cam SGAs
When cam synchronization is activated, cam signals are output with a hysteresis
that takes into account the approach direction (see Fig. 6-16, "Hysteresis of the
cam SGAs"). This helps to prevent the SGAs from "flickering" if the axis is posi-
tioned exactly on the cam.
The magnitude of the hysteresis is determined by the following data:
for 840D sl:
MD 36940: $MA_SAFE_CAM_TOL
(tolerance for safe software cams)
for SINAMICS S120:
p9540: SI motion, SN tolerance
Fig. 6-16
If the cam is incorrectly/inadmissibly parameterized, then this is indicated by Alarm
27033.
© Siemens AG, 2006. All rights reserved
SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) – 03.2006 Edition
Cam position
SGA = 1
SGA = 0
Hysteresis of cam SGAs
Safety Functions Integrated in the System/Drive
6.8 Safe software cams (SN)
Tolerance
for safe
cams
s
6-157