The LOCATE Command [MLEPC]

The LOCATE[1] command is used to preset the axis positions on the NC machine. This command is valid for all machine types but may not be available on specific machines. The following LOCATE functions are available:

The LOCATE command presets the coordinate registers by renaming the location at which the machine is currently positioned, to the coordinate values specified. The coordinate registers are reset to these values that are then output along with the appropriate code. Other post-processor constants, such as travel limits and rotary device center positions are adjusted accordingly. Processing then continues normally. The difference between the old and the new coordinates is stored for cancellation at a later point in the program. The LOCATE command may or may not have a cumulative effect depending on responses to QUEST.

The first format is the axis specific LOCATE command. The second format is called the parametric form LOCATE command. The third format is used to quickly remove and reinstate LOCATE shifts and will be discussed last. In all formats, specifying MANUAL will suppress the output of NC control tape. This can be used to preset axes to desired locations without causing codes to appear in the tape file. GENER will continue processing in exactly the same manner whether MANUAL is coded or not.

Parametric Format

This command format affects only linear axes and requires the values to be entered in a set order.

\textbf{LOCATE / } \big[ \textbf{ MANUAL}, \big] \begin{bmatrix}\,\begin{array}{l} \textbf{ON} \\ \textbf{OFF} \end{array} \; , \, \end{bmatrix} \; a,b \big[,c \big]

The initial ON or OFF indicates whether the axis positions are being set to specific values or are being reset to their original values. If omitted, ON is assumed (i.e., axes are being set).

The a, b and c scalar values specify in machine coordinates the new axis coordinate values to use. Values must be coded when setting the axes; values must not be coded when resetting the axes (i.e., OFF coded). The machine axes represented by the three scalars are dependent on the type of machine and the machining mode.

Machine

a

b

c

Horizontal lathe in turn mode

Z

X

na

Vertical lathe in turn mode

X

Z

na

Any lathe in mill mode

X

Y

Z

2 axis mill or punch press

X/U

Y/V

na

Other mills

X/U

Y/V

Z/W

The most common application of LOCATE is to preset the linear axes to some default position at the start of the program. For example the following command on a mill would cause the X and Y axes readouts to show zero (0) and the Z axis readout to show 12:

LOCATE/0,0,12

The specified positions are in machine coordinates, not CL coordinates. Note that coding MANUAL would cause GENER to internally reset the machine position to the specified location but no reset record would be output. A typical NC control block for this LOCATE command might be:

N123 G92 X0. Y0. Z12. $

Axis-Specific Format

This command format allows one or more axes to be set or reset individually by name.

\textbf{LOCATE / } \big[ \textbf{ MANUAL}, \big] \begin{bmatrix} \, \begin{array}{l} \textbf{ON} \\ \textbf{OFF} \end{array} \; , \, \end{bmatrix} \;\; {\small \sim} \! \begin{pmatrix} , \begin{pmatrix}\begin{array}{l} \textbf{XAXIS} \\ \textbf{YAXIS} \\ \textbf{ZAXIS} \\ \textbf{UAXIS} \\ \textbf{VAXIS} \\ \textbf{WAXIS} \\ \textbf{QUILL} \\ \textbf{AAXIS} \\ \textbf{BAXIS} \\ \textbf{CAXIS} \\ \textbf{AAXIS},\textbf{TABLE} \\ \textbf{BAXIS},\textbf{TABLE} \\ \textbf{CAXIS},\textbf{TABLE} \\ \textbf{RAM} \big[ ,n \, \big] \end{array}\end{pmatrix} \begin{bmatrix} ,\! \begin{array}{l} \textbf{ON} \\ \textbf{OFF} \end{array} \, \end{bmatrix} \big[ ,\mathit{value} \, \big] \end{pmatrix}

The initial ON or OFF indicates whether the axes are being set or reset respectively. If omitted, ON is assumed. This can be overridden for any specific axis by explicitly coding an ON or OFF following the axis name. See here for a table correlating axes name keywords with machine axes.

The scalar value must be coded if the axis is being set; it must not be coded if the axis is being reset (i.e., OFF coded). The value specifies in machine coordinates the axis coordinate value at the current location of the axis.

Applying and Removing Last Preset Positioning Offset

This command format may be used to quickly remove, or reinstate LOCATE shifts to a number of axes at one time.

\textbf{LOCATE / } \big[ \textbf{ MANUAL}, \big] \begin{pmatrix} \begin{array}{l} \textbf{ON} \\ \textbf{OFF} \end{array} \, \end{pmatrix}

If LOCATE/OFF is coded, the preset positioning shifts currently applied to all axes will be removed. After having removed LOCATE shifts using a LOCATE/OFF or LOCATE/OFF,XAXIS,YAXIS… command, all shifts removed may be reinstated automatically if LOCATE/ON is coded.