A01785 — SBT brake test configuration error

The safety monitoring channel has detected that the Safe Brake Test (SBT) is parameterized incorrectly: in the configuration as set, the brake test cannot be started, or cannot be started without an error. SBT stands for Safe Brake Test, SBC for Safe Brake Control. The drive stores an alarm value in r2124, to be interpreted as a decimal number, which identifies exactly which configuration was rejected.

• Error when parameterizing the brake test.
• In this configuration the brake test cannot be started, or cannot be started without error.

1. Read the alarm value in r2124 (interpret decimal) to identify which brake test configuration has been rejected.
2. Alarm value 1: check that motion monitoring functions have been enabled.
3. Alarm values 2 and 4: check the brake selection in p10202 — the configuration is rejected both when two internal brakes were configured (2) and when no internal brakes were configured (4).
4. Alarm value 8: the brake test is configured for an internal brake, however the safety brake control is not enabled; check p9602 (SI enable SBC CU) and p9802 (SI enable SBC MM). Note: from firmware version 5.1, SBT without SBC is also permitted for the internal brake.
5. Alarm value 16: check p9306 (SI Mtn fct_spc MM) and p9506 (SI Mtn fct_spc CU) — the safe brake test and Safety without encoder must not be enabled simultaneously.
6. Alarm value 32: the safe brake test is enabled together with vector U/f control; the safe brake test is not possible in this control mode.

• The message value is a placeholder; the alarm value is stored in r2124 and is to be interpreted decimal.
• 1: No motion monitoring functions have been enabled.
• 2: Two internal brakes were configured (p10202).
• 4: No internal brakes were configured (p10202).
• 8: The brake test is configured for an internal brake, however the safety brake control is not enabled (p9602/p9802).
• 16: The safe brake test and Safety without encoder are simultaneously enabled (p9306/p9506). This is not permissible.
• 32: The safe brake test and vector U/f control is enabled. The safe brake test is not possible in this control mode.

• r2124 — alarm value: read the decimal value here to see which SBT configuration error the drive has detected.
• p10202 — SI Motion SBT brake selection: check here which internal brakes are configured for the SBT; alarm values 2 and 4 report an impermissible selection.
• p9602 — SI enable SBC CU: check here whether Safe Brake Control is enabled on the CU side for alarm value 8.
• p9802 — SI enable SBC MM: the same check on the MM side for alarm value 8.
• p9306 — SI Mtn fct_spc MM: check here that SBT and Safety without encoder are not enabled together (alarm value 16).
• p9506 — SI Mtn fct_spc CU: the same check on the CU side for alarm value 16.

The manual gives one remedy: check the parameterization of the brake test, guided by the alarm value in r2124. Once the configuration no longer contains one of the rejected combinations, the brake test is no longer blocked by this message and can be started again. No acknowledgement is required for this alarm.