Software limit switches

Software limit switches are used to limit the travel range of an axis. Monitoring of the software limit switches can be activated and configured in the configuration menu of the software module during startup. See chapter Monitoring functions. The drive must be referenced to allow for monitoring the software limit switches.

If software limit switch monitoring is enabled, the following response will be triggered depending on the active operating mode as soon as the configured positive or negative limit switch position is exceeded:

  • Jog mode, position controlled (100)
  • The drive stops at the software limit switch position using the deceleration specified via PO 4. If "Limit switch fault response" is enabled, the error message E30.01/02 "Positive/negative limit switch hit" is issued.
  • Jog mode speed controlled (101) and velocity control (200)
  • The drive stops along the configured emergency stop ramp if the respective "Limit switch fault response" is activated. The error message E30.01/02 "Positive/negative limit switch hit" is issued.
  • Positioning mode (400 and 401)
  • If a target position is specified that lies beyond the position of a software limit switch, no travel job will be performed when the motor is at standstill. Otherwise, the drive stops with the deceleration set for the application limits. The error message E19.02 "Position setpoint violation" is issued.
  • Automatic (1400 and 1402)
  • When a software limit switch is reached, the inverter responds with the fault response set in the configuration of the inverter (in the "Monitoring functions" configuration menu in the "Overview fault responses" submenu) and the corresponding error message:
    • 16#3001 = Positive software limit switch hit
    • 16#3002 = Negative software limit switch hit

 

Error messages can be reset using PO 1.8 "Fault reset". First, specify a direction of rotation or a target position in the direction of the valid range of the software limit switches. If you wish to move the drive outside the range limited by the software limit switches, you have to disable the software limit switches using the PO 1:12 signal.