Table 4-5
Deselecting SBT
Step
Procedure
1st
Select SBT via SCC by setting bit 0 "SELECTION_SBT" to 0 in STW3 (signal edge 1 => 0).
See also: Selection (Page 176)
→
DRV initiates the de-selection process, and then in ZSW3 bit 1 "SETPOINT_SET‐
TING_DRIVE" is set to 0. The setpoint circuit from the NC is synchronized to the actual values
(setpoint position = actual position), the position is aligned and the contour and standstill
monitoring are reactivated.
See also: Sequence (Page 177)
2nd
In the associated axis DB, set bit "Start brake test" DBX11.0 = 0.
→
The "Brake test active" bit is set to 0 (DBX71.0 = 0) by the NC.
Canceling the brake test sequence (SBT)
If the brake test sequence (SBT) is canceled due to errors, then you can carry out the evaluation
and implement the resulting measures via the corresponding PLC interface signals.
See also: Cancellation/deselection and acknowledgment (SBT) (Page 178)
Note
Using MD36968.2 to select the parameter assignment behavior at the end of SBT
You can parameterize the positioning behavior after the brake test via the expert list using
MD36968.2 $MA_SAFE_BRAKETEST_CONTROL, bit 2:
● 0: Positioning at the actual axis position
To conclude the brake test, the actual axis position for the next path motion is used.
(MD36968 $MA_SAFE_BRAKETEST_CONTROL bit 2 = 0). This results in motion to the
last programmed axis position on the path.
● 1: Positioning to the last programmed axis position
Acceptance of the actual axis position is not carried out. After the axis has been pressed
against the brake, the closed-loop position controller withdraws the axis to the last
programmed position.
Vertical axes can thus be prevented from sagging as a result of a repeated brake test. It is
also possible to briefly exceed the software limit switch while pressing against the brake
without initiating an alarm.
4.15.1.3
Enabling the function
To enable the Safe Brake Test function, proceed as follows:
● Enable the Safe Brake Control (SBC) function when using an internal motor holding brake
(MHB): p9602 = 1.
● Select the SBT selection type:
Safety functions integrated in the drive
4.15 SBT
Safety Integrated (with SINAMICS S120)
Commissioning Manual, 02/2020, A5E46305916B AB
173