PLC interface

The PLC interface provides control units to switch channel access to the axes and to display the axes.

Interrupt output of command values to real axes

Description

This interrupts the output of NC channel command values to physical axes. The NC channel is stopped and assignment to the real axes is disabled.

Physical axes can then be requested and moved by another channel. A different logical axis can be linked to a physical axis here.

After clearing this interruption, the axes can be requested again and the original channel continues its motion.

Data type

MC_CONTROL_BOOL_UNIT, see description Control unit

Access

PLC reads request_r + state_r and writes command_w + enable_w

ST Path

gpCh[channel_idx]^.bahn_mc_control.suspend_axis_output

Commanded, requested and return values

ST Element

.command_w

.request_r

.state_r

Data type

BOOL

Value range

[TRUE, FALSE]

Redirection

ST element

.enable_w

Position offset

Description

Display of the current offset of the absolute position between the position controller axis (real physical axis) and the interpolator axis (logical axis) currently linked in the axis coordinate system.

The display here shows an offset between the interpolator position and the position controller position caused by the use of functions such as “jog of path” (see [FCT-C15].

The offset displayed contains no offsets caused by zero offsets, for example.

Signal flow

CNC → PLC

ST path

gpAx[axis_idx]^.lr_state.position_offset_r

Data type

DINT

Unit

0.1 µm

Access

PLC is reading

Axis supply

Description

The command of the physical axes is executed by the logical axis specified in the NC channel.

Signal flow

CNC → PLC

ST path

gpAx[axis_idx]^.lr_state.link_to_ipo_r

Data type

UINT

Value range

[= 0 – not linked, > 0 – logical axis number]

Access

PLC is reading

Axis assignment

Description

The display shows the physical axes to which the commanded values of the logical axes are of the channel output.

Signal flow

CNC → PLC

ST path

gpAx[axis_idx]^.ipo_state.link_to_lr

Data type

UINT

Value range

[= 0 – not linked, > 0 – logical axis number]

Access

PLC is reading