Look-Ahead Variables

There are many cases in which GENER goes into look-ahead mode to find the next CL record of a particular type. During look-ahead mode, tape generation is turned off and there is very limited processing of CL records. Look-ahead variables indicate if a certain type of look-ahead processing is in effect. Macros can test for these variables and exit processing (using a TERMAC command) to speed up the look-ahead process, or the macro can issue a post-processor command to trigger the end of the look-ahead (e.g., by outputting a LOAD/TOOL command to satisfy a tool look-ahead).

All look-aheads in a Composite post-processor, with the exception of $FLOOK, are limited to the current composite post-processor component. Look-aheads will end when an APPLY command is encountered that switches processing to a different component post-processor.

For more details about look-ahead processing, see “Macro Look-Ahead Processing”.

$ANYLOOK

True when in any form of look-ahead mode Type: Logical, Read-only

This variable is set to $TRUE when GENER is processing the macro in any form of look-ahead, which includes:

Built-in look-aheads as indicated by the $LOOKAH variable

Operation event (OE) look-aheads as indicated by the $OELOOK variable

$FLOOK function look-aheads as indicated by the $LOOK array variable

$FINFO function look-aheads as indicated by the $ILOOK variable

At all other times $ANYLOOK is set to $FALSE

$CLOOK

True when in $FCLINFO() look-ahead mode Type: Logical, Read-only

This variable indicates whether or not $FCLINFO() is scanning and analyzing CL file. This variable is deigned to help output OPTYPE or other commands while $FCLINFO() scan is active.

$HDLOOK

True when in merging lathe HEAD command look-ahead mode Type: Logical, Read-only

This variable indicates whether or not GENER is looking for a HEAD command before merging two head sequences in merge mode. It is set to $TRUE between the HEAD/BOTH and the HEAD/MAIN or HEAD/SIDE command that should immediately follow. It is also set to $TRUE when scanning through the first head sequence specified looking for the HEAD/SIDE or HEAD/MAIN command that divides it from the second head sequence. At all other times it is set to $FALSE.

$HOLOOK

True when in LOAD/HEAD command look-ahead mode Type: Logical, Read-only

This variable indicates whether or not GENER is looking for the next head to be loaded. It is set to $TRUE when scanning for the next head information and set to $FALSE otherwise.

$ILOOK

True when in $FINFO look-ahead mode Type: Logical, Read/Write

This variable is set to $TRUE when GENER is performing a $FINFO function look-ahead. A $FINFO look-ahead can be terminated early by setting the $ILOOK system variable to $FALSE.

$INFO.*

Information gathered while in $FINFO look-ahead mode Type: Various, Read/Write

The $INFO.* system variables contain the information gathered during a $FINFO look-ahead. These variables are preserved when the $FINFO or Operation Event (OE) look-ahead completes. The $FINFO variables are listed in “$FINFO Operation Look-ahead”.

$LCSLOOK

True when in LCS motion look-ahead mode Type: Logical, Read-only

This variable is set to $TRUE when GENER is analyzing positioning motions during automatic LCS activation or deactivation. It is set to $FALSE in normal circumstances.

$LOOK(context)

Look-ahead result for a $FLOOK look function call Type: Numeric, Read/Write

This array variable when used on the left hand side of an “=” sign will set the result for the $FLOOK function. At that instant, the original saved post-processing state is restored, the tape and listing outputs are re-enabled and the matching $FLOOK(n) function will return whatever value $LOOK(n) was set to. This variable can also be used on the right hand side of an “=” to determine if a look-ahead is active for the specified context number, returning 1 if active or 0 if not. For more details refer to “$FLOOK Generic Look-ahead”.

$LOOKAH

True when in internal look-ahead mode Type: Logical, Read-only

This variable is set to $TRUE when GENER is processing the macro in one of the following forms of internal look-aheads: $CLOOK, $HDLOOK, $HOLOOK, $MLOOK, $LCSLOOK, $PLOOK, $PPLOOK, $SCLOOK, $SCTLOOK and $TLOOK. It is set to $FALSE under normal circumstances.

Note that operation event (OE), $FLOOK() and $FINFO() type look-aheads do not affect the state of $LOOKAH.

$MLOOK

True when in motion look-ahead mode Type: Logical, Read-only

This variable is set to $TRUE when GENER is looking for a motion due to a motion look-ahead macro system variable being specified. It is set to $FALSE in normal circumstances.

$OE.*

Information gathered while in OE look-ahead mode Type: Various, Read/Write

The $OE.* system variables contain the information gathered during an Operation Event (OE) look-ahead. These variables are preserved when the Operation Event look-ahead completes. The $OE variables are listed in “Operation Event Look-ahead”.

$OELOOK

True when in OE look-ahead mode. Type: Logical, Read/Write

This variable is set to $TRUE when GENER is performing an Operation Event (OE) look-ahead. The OE look-ahead can be terminated early by setting the $OELOOK system variable to $FALSE.

$PLOOK

True when in PARTNO look-ahead mode Type: Logical, Read-only

This variable is set to $TRUE at the start of GENER processing, when a search for the first PARTNO CL record is performed. It is set to $FALSE otherwise.

$PPLOOK

True when in path planning look-ahead mode Type: Logical, Read-only

This variable is set to $TRUE when GENER is performing LINTOL/SCAN and related path planning look-ahead processing. It is set to $FALSE otherwise.

$SCLOOK

True when in SPINDL/COOLNT look-ahead mode Type: Logical, Read-only

This variable is set to $TRUE when GENER is looking ahead for a SPINDL or COOLNT command, for the purpose of outputting a combined spindle and coolant (M) code. It is set to $FALSE otherwise.

$SCTLOOK

True when in SmartCUT or SmartFEED look-ahead mode Type: Logical, Read-only

This variable is set to $TRUE when GENER is looking ahead during SmartCUT and SmartFEED processing. It is set to $FALSE otherwise. Note that SmartPATH processing is a form of path-planning look-ahead, identified by the $PPLOOK variable.

$TLOOK

True when in tooling look-ahead mode Type: Logical, Read-only

This variable is set to $TRUE when GENER is performing standard tooling look-ahead, or when it is looking ahead to determine the value of the $T variable. It is set to $FALSE otherwise.

$ULKHED

Set True when processing a user written look-ahead Type: Logical, Read/Write

This variable should be set $TRUE before processing TAPERD and/or SEARCH functions as part of a user written look-ahead operation. This variable should be set $FALSE after the final SEARCH that resets the CL input position following the look-ahead processing. GENER uses this information to more accurately update the progress bar to show true progress.