Operation Principle; Sls Function - ABB ACS880-07 User Manual

• The monitoring limits for the deceleration ramp (a time limit or ramp monitoring limits)
are set according to application needs. These are FSO module parameters that the
user must set at the start-up.
The wirings and settings of the SMS function are:
• The drive is equipped with the FSO-21 safety functions module (option +Q972). ABB
installs the module at the factory.
• There are two different versions of the SMS function. Version 1 monitors the motor
speed and trips the drive if the user-defined trip limit is exceeded. Version 2 of the SMS
function is similar to the SLS function except that it can only be configured to be
continuously on or off. ABB activates the SMS function (Version 1) at the factory. This
is an FSO module parameter that the user must check/set at the start-up.
• The SMS positive and negative speed limits are FSO module parameters that the user
must set at the start-up.
The wirings and settings of the SSM function are:
• The drive is equipped with the FSO-21 safety functions module (option +Q972). ABB
installs the module at the factory.
• ABB activates the SSM function at the factory (Always on). This is done with FSO
module parameters that the user must check/set at the start-up.
• The user wires the SSM indication signal (for example, an indication lamp) to the FSO
module.
• The digital output of the FSO module to which the SSM indication signal is connected,
is selected as the output for the SSM output. This is an FSO module parameter that
ABB sets at the factory by default and the user must check at the start-up.
• The SSM positive and negative speed limits are FSO module parameters that the user
must set at the start-up.
For a detailed description of wirings, see sections Wiring and Operation principle diagram.
For a detailed description of parameter settings, see chapter Parameter settings.

Operation principle

￭

SLS function

The SLS function makes sure that the motor speed does not exceed the user-defined speed
limits when the function is active. The user defines the SLS limits and SLS trip limits at the
start-up. When the user activates the SLS function, the FSO module sends the SLS request
to the drive. The drive takes the SLS parameters into use and controls the motor speed
accordingly until the user deactivates the SLS request.
If the motor speed is above/below the user-defined SLS limit positive/negative when the
SLS function is activated, the motor speed is first decelerated to the required speed. The
SLS function monitors the deceleration to the required speed either with the time or ramp
monitoring method.
When the SLS function is active, the drive limits the motor speed so that it cannot exceed
the SLS limits.
Note: It is a good practice to define the motor speed reference so that it stays between the
SLS limits in the operating situations when the SLS function is active.
If the motor speed reaches the user-defined SLS trip limit, the FSO module activates the
Safe stop emergency (SSE) function of the FSO module. Depending on parameter settings,
Option description 17