SLP (Safely Limited Position)

SLP description for drive option Functional Safety 3.

Description

When active, SLP monitors the position and ensures that it stays in a position window. The upper limit of the position window is defined by the parameter s_UL_SLP and the lower limit is defined by the parameter s_LL_SLP. If the position leaves this position window while the function is active, a configurable fault reaction will be activated.

If necessary, the start of monitoring can be delayed by using the configurable parameter t_D_SLP.

Number of instances

Three instances per axis.

Function Input / Output Variables

 

 

Inputs

• SLP Activate can be triggered by FSoE or safe digital inputs (must be mapped)
• Safe Position: position signal from safe feedback

Outputs

• SLP Active: logical status of the SLP function
• Fault Activate: activate fault reaction

Activation

Activation by FSoE	For a drive profile overview, see FSoE (➜ # 1, FSoE). For setup and handling, see the AKD2G EtherCAT Manual.
Activation by safe digital inputs	To review the enclosure and wiring instructions, see Enclosure, wiring (➜ # 1, Enclosure, wiring). To see technical data for the safe inputs, see Technical Data (➜ # 1, Technical Data). For notes on activation by safe inputs, see Activation by Safety Digital Inputs (➜ # 1, Activation By Safe Digital Inputs).

Timing

Related Parameters

Safety parameters

Name	Variables	Default	Parameter
Function Activation	-	0 (Never active)	AXIS#.SAFEPARAM.SLP_#​.FUNCTIONACTIVATION
Safe Input	-	0 (Not used)	AXIS#.SAFEPARAM.SLP_#​.SAFEINPUT
FSoE	-	0 (Not used)	AXIS#.SAFEPARAM.SLP_#​.FSOE
Position Upper Limit	s_UL_SLP	1 (Pos user units)	AXIS#.SAFEPARAM.SLP_#​.POSUPPERLIMIT
Position Lower Limit	s_LL_SLP	1 (Pos user units)	AXIS#.SAFEPARAM.SLP_#​.POSLOWERLIMIT
Time Delay Monitoring	t_D_SLP	0 ms	AXIS#.SAFEPARAM.SLP_#​.TIMEDELAYMONITORING
Fault Reaction	-	1 (STO)	AXIS#.SAFEPARAM.SLP_#​.FAULTREACTION

Diagnostic parameters

Name	Variables	Default	Parameter
Function Active Status	-	-	AXIS#.SAFE.SLP_#.ACTIVE
Function Internal Status	-	-	AXIS#.SAFE.SLP_#​.INTERNALSTATE

 

State Diagram

SLP is active if internal state is "Monitoring (1)" or "Fault reaction (2)".

 

Setup in WorkBench

Select the drive and open the Safety Parameterization view Parameters Editor.

Choose axis (1), category (2), SLP function (3) and the instance number (4).

Fault Reaction / Failure Messages

SLP 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, SLP remains active and the internal state
(AXIS#.SAFE.SLP_#​.INTERNALSTATE) is set to failed state (2).

Safety State / Status Signals

The signal AXIS#.SAFE.SLP_#.ACTIVE can be monitored by safe digital outputs with OSSD pulses. 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 Safety Properties Overview.