SS1-t (Safe Stop 1)

SS1-t (time controlled) description for drive option Functional Safety 2 or 3.

Description

With the time based function "Safe Stop 1" (SS1-t) the drive is stopped by a controlled stop with the configured deceleration ramp. When the time t_SS1 (➜ # 1, AXIS#.SAFEPARAM.SS1_#.TIMETOSTO) is elapsed, STO is activated. SS1 Instance 1 can be configured as the fault reaction for safety functions SS2, SSR, SDI, SLA, SAR, SLI,SLP and SLS.

SS1 function corresponds to a controlled stop according to IEC 60204-1, stop category 1. The controlled stop is executed in the unsafe part of the drive. The deceleration ramp (➜ # 1, AXIS#.SAFE.SS1_#.DEC) is part of the standard drive parameter. The STO function is a safe function.

Function Input / Output Variables

Inputs

SS1 Activate can be activated by
FSoE,
I/O failure (instance 1 only),
safe digital inputs (must be mapped) or
other safety functions as fault reaction.

Outputs

SS1 Active: logical status of the SS1 function
STO Active: logical status of the STO function
STO Activate is activated by SS1

Number of Instances

Three instances per axis.

Activation

To use SS1-t, Velocity & Deceleration Monitoring must be disabled in the safety parameters on a FS3 drive. On a FS2 drive, only SS1-t is available.

If SS1_2 or SS1_3 is set to “Not Used”, the corresponding FSoE activation bit is ignored even if (➜ # 1, SAFEPARAM.SAFEFIELDBUS.ACTIVATION) is 1.

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).

Safety Properties

Refer to (➜ # 1, Safety Properties Overview).

Restart

(➜ # 1, STO (Safe Torque Off))

Timing

Notes:

SS1 is fully completed after activation until STO is activated, even if the request (SS1_Activate) is reset in between.
The additional time for the optional closing of the brakes is not included in this diagram. For more information refer to (➜ # 1, SBC (Safe Brake Control))
See limitations for FSoE (➜ # 1, Limitations for SMM 1.04) (➜ # 1, Limitations for SMM2)

Related Parameters

Safety parameters

Name	Variables	Default	Parameter
Function Activation	-	Inst. 1: 1 (Ready for activation) Inst. 2,3: 0 (Never active)	(➜ # 1, AXIS#.SAFEPARAM.SS1_#.FUNCTIONACTIVATION)
Safe Input	-	0 (Not used)	(➜ # 1, AXIS#.SAFEPARAM.SS1_#.SAFEINPUT)
FSoE	-	0 (Not used)	(➜ # 1, AXIS#.SAFEPARAM.SS1_#.FSOE)
Time To STO	t_SS1	2 ms	(➜ # 1, AXIS#.SAFEPARAM.SS1_#.TIMETOSTO)
Velocity & Deceleration Monitoring	-	0 (Disabled)	(➜ # 1, AXIS#.SAFEPARAM.SS1_#.VELDECMONITOREN)

Diagnostic parameters

Name	Variables	Default	Parameter
Function Active Status	-	-	(➜ # 1, AXIS#.SAFE.SS1_#.ACTIVE)
Function Internal Status	-	-	(➜ # 1, AXIS#.SAFE.SS1_#.INTERNALSTATE)

Device parameters

Name	Variables	Default	Parameter
Deceleration Mode	-	0 (Drive driven)	(➜ # 1, AXIS#.SAFE.SS1_#.MODE)
Deceleration Ramp	-	9999.946 rpm/s	(➜ # 1, AXIS#.SAFE.SS1_#.DEC)

State Diagram

SS1-t is active when its internal state is in state "Delay Before STO (1)".

Setup in WorkBench

Select the drive and open the Safety Parameterization view (➜ # 1, Parameters Editor).

Choose the axis
Select the category
Select the SS1 function
Select the instance number

If one dual input (e.g. SIN1/SIN2) activates SS1-t for both Axis 1 and Axis 2, set the Activation parameter for both axes to the identical input (e.g. Safe Dual Input 1).

Fault Reaction / Failure Messages

If dual channel mode is selected, the AKD2G sees if the two inputs are in a different state for more than 100 ms. If the two inputs are in different state for more than 100 ms, an I/O failure activates SS1_1 and then STO is activated. An I/O failure warning is displayed.

SS1 Instance 1 can be configured as the fault reaction for other safety functions. Functions which support this feature are SS2, SSR, SDI, SLA, SAR, SLI, SLP and SLS.

Safety State / Status Signals

The signal AXIS#.SAFE.SS1_#.ACTIVE can be monitored by safe digital outputs with OSSD pulses (➜ # 1, 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 see (➜ # 1, Functional Safety Parameter Reference).