SSx

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Description

The SS1 and SS2 safety sub-functions defined in standard IEC 61800-5-2:2016 can be realized with the SSx safety sub-function. The safe stop with time control SSx‑t and the safe stop with monitoring of the deceleration ramp (linear and jerk-limited) SSx‑r are both supported.

The parameters can be used to define which variant of the SSx safety sub-function is used:

Setting of the parameter
Selected final state

Setting of the parameter
Ramp monitoring

SSx variant

None

SS1‑t

Linear/Jerk-limited

SS1‑r

None

SS2‑t

Linear/Jerk-limited

SS2‑r

The following actions are performed for the SSx variants:

  • The SS1-t safety sub-function monitors the time period until the final status. The deceleration ramp must be completed within this time period. After this time period, the STO safety sub-function is activated.
  • The SS1-r safety sub-function monitors the deceleration ramp within the defined limits.
  • If the limit value is exceeded, the STO safety sub-function is activated immediately. The brake application time is not taken into account.
  • If the calculated speed falls below the value of the Minimum speed for speed function parameter from the parameter group Basic settings, the STO safety sub-function is activated.
  • The SS2-t safety sub-function monitors the time period until the final status. The deceleration ramp must be completed within this time period. After this time period, the SOS safety sub-function is activated.
  • The SS2-r safety sub-function monitors the deceleration ramp within the defined limits.
  • If the limit value is exceeded, the STO safety sub-function is activated immediately. The brake application time is not taken into account.
  • If the calculated speed falls below the value of the Minimum speed for speed function parameter from the parameter group Basic settings, the SOS safety sub-function is activated.

In the instances of the SSx safety sub-function (SSx 1 and SSx 2), 2 of the 4 SSx variants can be parameterized, which can be defined as an error response of a safety sub-function or when safe communication is aborted.

The safety sub-function can be activated as follows:

  • Via a safe digital input F‑DI
  • Via the safe process data of the higher-level safety controller