SAR (Safe Acceleration Range)
SAR description for drive option Functional Safety 3.
Description
SAR, when active, monitors the acceleration and ensures that it stays in an acceleration window. The acceleration window is defined by two parameters: a_UL_SAR (acceleration upper limit) and a_LL_SAR (acceleration lower limit). If the acceleration leaves the acceleration window a configurable fault reaction will be activated.
Number of instances
Three instances per axis.
Function Input/Output variables
Inputs
- SAR Activate can be triggered by FSoE or safe digital inputs (must me mapped)
- Safe acceleration: acceleration signal from safe feedback
Outputs
- SAR Active: logical status of the SAR function
- Fault Activate: activate fault reaction
Activation
Activation by FSoE |
|
Activation by safe digital inputs |
|
Timing
Related Parameters
Safety parameters
Name |
Variables |
Default |
Parameter |
---|---|---|---|
Function Activation |
- |
0 (Never active) |
|
Safe Input |
- |
0 (Not used) |
|
FSoE |
- |
0 (Not used) |
|
Acceleration Upper Limit |
a_UL_SAR |
1 (Acc user units) |
|
Acceleration Lower Limit |
a_LL_SAR |
1 (Acc user units) |
|
Fault Reaction |
- |
1 (STO) |
Diagnostic parameters
Name |
Variables |
Default |
Parameter |
---|---|---|---|
Function Active Status |
- |
- |
|
Function Internal Status |
- |
- |
State Diagram
SAR is active if internal state is "Monitoring (1)" or "Fault reaction (2)".
Setup in WorkBench
Select the drive and open the Safety Parameterization view see "Parameters Editor".
Choose the axis (1), category (2), SAR function (3) and the instance number (4).
Fault Reaction / Failure Messages
SAR has a configurable fault reaction. STO is used by default but can be replaced by SS1 Instance 1 or SS2 Instance 1. When the fault reaction is activated, SAR remains active and the internal state (AXIS#.SAFE.SAR_#.INTERNALSTATE) is set to failed state (2).
Safety State / Status signals
The signal AXIS#.SAFE.SAR_#.ACTIVE can be monitored by safe digital outputs with OSSD pulses see "OSSD". The status signal must be mapped to the safe digital output. Two outputs can be combined to a dual channel output. For parameter description refer to Functional Safety Parameter Reference.
Safety Properties
Refer to (➜ # 1, Safety Properties Overview).