Siemens SINUMERIK 840D sl Manual page 164

Connection of the Components
5.12 Brake Control
Safe brake control (SBC)
Note
The "Safe brake control" function is activated only in conjunction with the enable of the "Safe
standstill" (SH) function.
The "Safe brake control" does not detect any fault in the holding brake itself, such as a short-
circuit of the brake winding, brake worn out, etc.
Wire breakage will be monitored only for each activation of the brake, not, however, during
operation.
The control paths must be provided as two channels for the "Safe brake control". This is
performed with a separate control by the Control Unit and the Motor Module. These units
switch and monitor the brake control independent of each other.
For safety-related functions, it is necessary for the fault detection to perform in a defined
interval a test using forced dynamization. In this case, the switch-off path must be performed
and tested in the two monitoring channels at least once within a defined interval. The "forced
dynamization" cycle must be controlled appropriately externally and mechanically, for
example, using a brief interruption of the two "Safe standstill" (SH) inputs on the Control Unit
and on the Motor Module.
The dynamization is also performed:
● For each brake control with "open holding brake" and "close holding brake"
● For selection of the "Safe standstill" function
When the "Safe standstill" function is selected, an internal OFF2 command will be issued
and the holding brake closed immediately.
5-80
Note
The monitoring and the forced checking procedure of the brake outlet is possible only
when the brake is connected directly and not using a coupling relay to the connection
terminals! The p9602 and p9802 parameters can be used to specify the control operation.
The "Safe brake control" is performed independent of the setting in p1215. A "Safe brake
initiation" always has priority over the conventional brake control.
Guide for the SINUMERIK 840D sl machine configuring
Manual, 07/2006 Edition, 6FC5397-6CP10-0BA0