6 safe stop 2 (ss2), Safe stop 2 (ss2), Is a – Lenze E94AYAE SM301 User Manual
Page 46: Function is a, Tion, 3safe configuration

3
Safe configuration
3.9
Safety functions
46
Lenze · SM301 safety module · Parameter setting & configuration · DMS 2.3 EN · 11/2013 · TD05
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3.9.1.6
Safe stop 2 (SS2)
Note!
When the stopping time has elapsed, the safe stop 2 (SS2) function switches to the safe
operating stop (SOS). This function has been implemented in the SM301 up to version
V1.2 in the form of speed range monitoring.
• This means that the SOS function and, consequently, also the SS2 function have not
been implemented in accordance with the IEC 61800-5-2 standard, which clearly
requires the monitoring of a position window in section 4.2.3.1.
From SM301 V1.3
• position-window monitoring has been implemented.
• it is possible to change to the safe operating stop before the stopping time has
elapsed as soon as the standstill has been identified. This behaviour can be
parameterised.
Safe Stop 2 / SS2 (corresponds to a "Stop 2" in accordance with EN 60204)
Description
The safety module monitors whether the drive has reached the set tolerance margin (n=0)
within the parameterised stopping time and, depending on the parameterised SS2 mode, after
the stopping time has elapsed or after falling below the tolerance margin (n=0), activates the
monitoring of the safe operating stop (SOS).
In the safe operational stop the drive is not switched to torque-free operation but all control
functions remain active and the position reached must be maintained actively.
•
From SM301 V1.4
additionally the deceleration ramp for the SS2 stop function can be
parameterised and monitored.
Ramp monitoring (SS1/SS2) ( 48)
• The application must ensure that the drive is braked to standstill and the position is
maintained!
• The speed and the position data are calculated from the encoder data.
measurement and position detection ( 31)
• Without an encoder the function cannot be used.
• Additional measures are required against movements caused by external forces, e.g.
mechanical brakes. The application time of a brake must be considered when determining
the stopping time.
• A restart is only possible after the stopping time has elapsed completely. This does not apply
to special operation.
Priority
Priority functions:
Function
From SM301 V1.3, function (SOS with n=0) can be selected as SS2 mode.
Parameter
SS2 mode:
SOS after stopping time
SOS with n=0
SS1, SS2: Stopping time
Speed window (n=0)
SOS: Tolerance margin (delta p=0) *
0
1
n
t
0
STO
SOS
SS2
n
t
0
STO
SOS
SS2