11.03
8 Application examples
8.3 Testing the function of the brake mechanical system
© Siemens AG 2003 All Rights Reserved
SINUMERIK 840D/SIMODRIVE 611 digital SINUMERIK Safety Integrated (FBSI) - Edition 11.03
8-451
For SIMODRIVE 611 digital, the drive torque is determined at the time when
the function test is selected. It is thus possible to take into a deviation from the
torque parameterized in the drive machine data 1192 (or force due to the
weight). This ensures that the brake test can also be carried-out with varying
machine loads (e.g. different workpieces or tools). The drive torque to load the
holding brake is limited to the maximum motor torque if the desired braking
torque would require a higher drive torque.
m
t
MD BRAKETEST_TORQUE
0
Measured torque on
selection of brake test
m
Torque limiting in current
controller
611D-MD 1192
m
Act
Drive
m
Drive
MD 1192 + / - m
FXS
m
FXS
m
FXS
Fig. 8-5
Torque limiting for 611 digital
When selecting the brake test, the holding torque required for the weight of the
axis is measured internally (m
Act
). The drive must only provide the difference
between this torque and the braking torque specified in MD
$MA_SAFE_BRAKETEST_TORQUE. This torque is designated with a m
Drive
in
Fig. 8-5. The SIMODRIVE 611 digital drive locates its torque limit symmetrically
around the torque specified in drive machine data 1192. This is the reason that
m
FXS
from Fig. 8-5 is specified as torque limit. m
FXS
is the sum of m
Drive
and MD
1192. If the measured torque m
Act
coincides with the the parameterization in
MD 1192, then m
FXS
becomes the value from MD
$MA_SAFE_BRAKETEST_TORQUE
Incorrect parameterization in MD $MA_SAFE_BRAKETEST_TORQUE or drive
machine data 1192 can mean that the drive with reduced torque cannot even
apply the required holding torque. This parameterization is detected when the
brake test is selected and produces Alarm 20095 (refer to Chapter 6). The fact
that the actual torque/force setpoint is displayed in MD 1728 makes it easier to
correctly parameterize drive machine data 1192. If only the force due to the
weight is effective, then this value can be directly transferred into MD 1192.