Software limit positions

The parameterisable limit positions serve to limit the traversing range by the software.

Note!

Evaluation and monitoring of the software limit positions are only carried out if

  • the drive knows the home position,
  • the software limit positions are activated via subindex 50 and
  • monitoring has not been deactivated from the application.

In case of the "Modulo" traversing range and in the device states "Homing", "ErrorStop" and "Disabled", the software limit positions are usually not active.

  • The information that monitoring of the software limit positions is really effective is provided at the FB MC_ReadAxisInfo and FB L_MC1P_AxisBasicControl via the xSWLimitEnabled output.
  • From the application, monitoring of the software limit positions can be deactivated via the following FBs (temporarily):
  • When the SW limit position is exceeded, the system switches to the "ErrorStop" state. "Retraction" of the SW limit positions is possible in the direction of the permitted range. The desired error response can be configured in subindex 105 .
  • For motion control FBs which cause a change to the "ContinuousMotion" or "DiscreteMotion" state, the behaviour can be set in subindex 53 .
    For FBs which switch the axis to the "SynchronizedMotion" state (e.g. MC_GearIn ), no check is carried out in advance. The axis is not stopped until the SW limit positions have been exceeded.

Software limit position monitoring (subindex 50)

Virtual axis 9400 HighLine i500 inverter i700 servo inverter i950 servo inverter Encoder

Activate software limit positions (switch effectively)

Selection list (Lenze setting printed in bold)

Info

0

Deactivated

Not activated

1

Activated

Activated

Read access Write access Can only be changed in "Disabled" state No download

UNSIGNED_8

Positive software limit position (subindex 51)

Virtual axis 9400 HighLine i500 inverter i700 servo inverter i950 servo inverter Encoder

Positive software limit position

Setting range (min. value | unit | max. value)

Lenze setting

Unit

0.0 unit

Read access Write access Can only be changed in "Disabled" state No download

FLOAT_64

Negative software limit position (subindex 52)

Virtual axis 9400 HighLine i500 inverter i700 servo inverter i950 servo inverter Encoder

Negative software limit position

Setting range (min. value | unit | max. value)

Lenze setting

Unit

0.0 unit

Read access Write access Can only be changed in "Disabled" state No download

FLOAT_64

Behaviour - SW limit pos. monit. (subindex 53)

Virtual axis 9400 HighLine i500 inverter i700 servo inverter i950 servo inverter Encoder

General behaviour of the motion-activating FBs in case of active software limit positions that put the axis into the Continuous Motion or Discrete Motion state.

Selection list (Lenze setting printed in bold)

Info

0

Stopping behind the limit

No monitoring of the software limit positions is made in the motion-activating FBs. Only if the software limit positions are crossed, an error is triggered.

1

Stopping on the limit

Depending on the motion-activating FB, it is already checked if the software limit positions are crossed as soon as the motion is activated.

  • MC_MoveVelocity : The FB directly stops on the software limit position.
  • Positioning FBs ( MC_MoveAbsolute , MC_MoveRelative , ...): If the target position is outside of the software limit positions, an error is output at the FB and the motion task is not executed.

Read access Write access Can only be changed in "Disabled" state No download

UNSIGNED_16

Behaviour in case of active software limit positions

If the software limit positions are active, travelling commands that would result in exiting from the permissible travel range can no longer be executed:

Parameterised negative software limit position

Parameterised positive software limit position

Travel command possible

Travel command not possible since the target position is outside of the permissible traversing range.

[4-15] Example: Traversing range limitation by means of software limit positions

If the axis is already outside the permissible travel range and the software limit positions have been activated, only travel commands that result in the axis moving back into the permissible travel range can be executed:

Parameterised negative software limit position

Parameterised positive software limit position

Traversing in "retracting direction" is possible

Traversing opposite to the "Retracting direction" is not possible

[4-16] Example: Permissible traversing direction if software limit positions active

If the software limit positions are active and a software limit position is passed ("overtravel"):

  • The error message "SWLimitPos" or "SWLimitNeg" is generated.
  • The output SWLimitSwitchPos or SWLimitSwitchNeg of the FB MC_ReadAxisInfo is set to TRUE.
  • The axis state changes to "ErrorStop", i.e. the axis is braked to a standstill depending on the error response configured in subindex 105 .
    The axis can only be traversed again after the error has been acknowledged via MC_Reset .

Response - software limits exceeded (subindex 105)

Virtual axis 9400 HighLine i500 inverter i700 servo inverter i950 servo inverter Encoder

Selection list (Lenze setting printed in bold)

19

Error->Fast stop

21

Error->QSP->CINH

Read access Write access Can only be changed in "Disabled" state No download

UNSIGNED_8