Measurement methods (P-AXIS-00516)

Value

Meaning

DRIVE_TYPE_DEFAULT

The CNC uses the default measuring method of the given drive type (see table below /*/)

PLC

This parameter setting reads the probing signal via the Control Unit lr_mc_control.probing_signal on the HLI [HLI]. The probing value is the actual value at the moment of the occurrence of the probing signal. As an alternative, the probing position can be specified directly via the control unit lr_mc_control.probing_position.

NOTE:

Due to the scanning of the probing signal in the cycle time of the PLC, the accuracy of the probed value is less than the accuracy achieved by using drive-internal probing latches.

This setting corresponds to the old parameter kenngr.probing_signal_via_plc (P-AXIS-00257)

FIXED_STOP

This setting searches for a fixed stop during the measuring traverse. In addition, the measurement type 7 (see P-CHAN-00057) must be selected.

CAUTION:

The user has to ensure that, during the movement to a fixed stop in the drives affected, a torque limitation is active and that the velocity is low enough.

This setting corresponds to the old parameter kenngr.meas_signal_fixed_stop (P-AXIS-00330)

DRIVE

This parameter defines that the probing signal is supplied by the drive. Additional settings in the drive are required (see [FCT-C4]).

This setting corresponds to the old parameters kenngr.mess_signal_taster (P-AXIS-00117), kenngr.mess_signal_sercos (P-AXIS-00116), kenngr.meas_signal_drive (P-AXIS-00269)

PLC_EXT_LATCH_­CONTROL

This setting defines that operation requires an external hardware for the measurement travel. Therefore the CNC informs the PLC via the external measuring interface about the start and end of a measuring travel so that the PLC can enable or disable the measurement hardware accordingly (see [HLI//Measuring with external probing hardware]). This method specifies the probing signal and the measured position via the control units lr_mc_control.probing_signal and lr_mc_control.probing_position.

PLC_FIRST_EVENT

This setting corresponds to the value “PLC“. However, the measuring travel stops as soon as the measurement event is detected at an axis measured with this setting. In “PLC mode, however, a measurement event must occur in the control unit lr_mc_control.probing_signal at every measured axis.

This setting corresponds to the old parameter kenngr.mess_signal_achs_steuer (P-AXIS-00115)

Drive type (see P-AXIS-00020)

Probing signal source default setting

Conventional

Sercos

Profidrive

Beckhoff Lightbus

+-10V via field bus (terminal)

RT-Ethernet

CANopen

CAN-Bus

DRIVE

Drive simulation

Virtual axis

PLC_FIRST_EVENT

Drive type (see P-AXIS-00020)

PLC

FIXED_STOP

DRIVE

PLC_EXT_LATCH_­CONTROL

PLC_­FIRST_-EVENT

Conventional

X

X

X

X

X

Sercos

X

X

X

X

X

Profidrive

X

X

X

X

-

Beckhoff Lightbus

X

X

X

X

-

+-10V via fieldbus (terminal)

X

X

X

X

-

RT-Ethernet

X

X

X

X

-

CANopen

X

X

X

X

-

CAN-Bus

X

X

X

X

-

Drive simulation

X

X

(X)*

X

X

Virtual axis

X

X

(X)*

X

X