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Safety Integrated Functions

8.5 Safety Integrated Extended Functions

Function Manual

Function Manual, 06/2012, 6SL3097-4AB10-0BP4

385

8.5.7 Safe Speed Monitor (SSM)

The "Safe Speed Monitor" (SSM) function provides a reliable method for detecting when a

speed limit has been undershot (p9346/p9546) in both directions of rotation, e.g. for zero

speed detection. A fail-safe output signal is available for further processing.

The function is activated automatically as soon as the Safety Integrated Extended Functions

are enabled with parameters p9301.0 = p9501.0 = 1 and p9346/p9546 > 0. SSM is

deactivated if p9346/p9546 = 0.

NOTICE

If 0 is entered for p9368/p9568, the speed limit of the SSM function (p9346/p9546) is

simultaneously the minimum limit for the safe acceleration monitoring function (SAM).

In this case, the effect of safe acceleration monitoring is therefore restricted if a relatively

high SSM/SAM speed limit is set when using the SS1 and SS2 stop functions.

WARNING

A STOP F is indicated by Safety message C01711/C30711. STOP F only results in the

follow-up response STOP B / STOP A if one of the Safety functions is active. If only the

SSM function is active, a STOP F cross-checking error does not result in a STOP B /

STOP A follow-up response.

SSM is only valid as an active monitoring function if p9301.0 = p9501.0 ≠ 0 and

p9346 = p9546 ≠ 0 and "Hysteresis and filtering" is parameterized

(p9301.16 = p9501.16 = 1).

If "Hysteresis and filtering" is not parameterized (p9301.16 = p9501.16 = 0), SSM is not

valid as an active monitoring function, but instead has only an informative character.

Note

You must carefully observe the following rules when parameterizing hysteresis and actual

value synchronization:

• If "SSM hysteresis" has been enabled (p9501.16 = p9301.16 = 1), you must set

parameters p9546/p9346 and p9547/p9347 according to this rule:

p9546 ≥ 2 × p9547

p9346 ≥ 2 × p9347

• If "Actual value synchronization" has been enabled (p9501.3 = p9301.3 = 1), you must

also observe this rule:

p9549 ≤ p9547

p9349 ≤ p9347