Virtual Machine Variables

The $KINENG Variable

$\textbf{{\char36}KINENG}$

Kinematics engine

Type: Numeric, Read/Write

The $KINENG variable defines the kinematics engine used by Virtual Machine during MCD based simulation. It is set in the questionnaire General Description / General Information section question #6.5 “VM kinematics engine”. Normally a value of 1 (one) is used, which makes Virtual Machine responsible to compensate for pivot-point offsets and perform tool-tip linearization (i.e., RTCP) in the same manner as modern CNC controllers. A value of 0 (zero) can be used to retain compatibility with earlier releases, which relies on the post-processor to perform these calculations for VM. Other kinematic engines are available for special purposes.

The $PART Variable

$\textbf{{\char36}PART}$

Current active part

Type: Numeric, Read/Write

The $PART variable indicates from which stock axis subsequent tool axis traces should be attached (the tool path trace moves as the indicated stock axis moves). The part identification is a numeric value matching the “part ID” specified with a stock axis.

The $REFHP Variable

$\textbf{{\char36}REFHP}$

Home position reference ID

Type: Numeric, Read/Write

The $REFHP variable specifies the model reference position ID to use by default when GENER or CERUN processes a reference home motion. It is initialized at the start of processing to the lowest “home position” reference ID defined in the model. It can be changed under macro processing to affect the position of the next reference home action. A value of -1 indicates that no reference home position is defined.

The $REFTC Variable

$\textbf{{\char36}REFTC}$

Tool change position reference ID

Type: Numeric, Read/Write

The $REFTC variable specifies the model reference position ID to use by default when GENER or CERUN processes a tool change motion to a “special” reference position. It is initialized at the start of processing to the lowest “tool change” reference ID defined in the model. It can be changed under macro processing to affect the position of the next tool change action. A value of -1 indicates that no special tool change reference position is defined.

The $VMACTTOOL Variable

$\textbf{{\char36}VMACTTOOL}$

Enable MRS tool cutting

Type: Logical, Read/Write

The $VMACTTOOL variable when set true enables material removal cutting even though the tool might not be spinning. This can be used to simulate ultrasonic tools, EDM wire cutting, punch press and other forms of non-rotating cutting tools.

The $VMCHN Variable

$\textbf{{\char36}VMCHN}$

Current active channel

Type: Numeric, Read/Write

The $VMCHN variable sets the current active channel number. By default, a merging lathe side head is controlled by channel 2; the main head (and all other machine types) by channel 1. This default channel assignment can be changed by setting $VMCHN.

The $VMDRAW Variable

$\textbf{{\char36}VMDRAW}$

Simulation window update state

Type: Logical, Read/Write

The $VMDRAW variable controls the Simulation window redraw functionality. It is normally $TRUE, causing the simulation window to be updated as normal. Setting $VMDRAW=$FALSE will stop further updates to the Simulation window, except when processing is paused. A macro that makes many $FMS function calls in succession may run considerably faster when processed with $VMDRAW set false. Be sure to reset $VMDRAW=$TRUE before exiting the macro.

The $VMP[L]{XYZ}M Variables

$\textbf{{\char36}VMP}\textbf{[}\textbf{L}\textbf{]}\texttt{\{}\textbf{XYZ}\texttt{\}}\textbf{M}$

Current and last X, Y and Z axis probe position

Type: Numeric, Read-only

$VMPXM $VMPYM $VMPZM $VMPLXM $VMPLYM $VMPLZM

These variables contain the machine X, Y and Z axes values at the start and end of a probing motion (i.e. when $FMSPROB is active and $VMPRCOD>0). $VMPXM, $VMPYM and $VMPZM refer to the linear machine axes positions when the probe was triggered. $VMPLXM, $VMPLYM and $VMPLZM refer to the linear machine axes positions at the start of the probe motion.

The $VMP[L]{XYZ}W Variables

$\textbf{{\char36}VMP}\textbf{[}\textbf{L}\textbf{]}\texttt{\{}\textbf{XYZ}\texttt{\}}\textbf{W}$

Current and last LCS X, Y and Z axis probe position

Type: Numeric, Read-only

$VMPXW $VMPYW $VMPZW $VMPLXW $VMPLYW $VMPLZW

These variables contain the local coordinate system (LCS) X, Y and Z axes values at the start and end of a probing motion (i.e. when $FMSPROB is active and $VMPRCOD>0). If a local coordinate frame is not active then these variables return the probe start and end machine linear axes instead (e.g., $VMPZW returns $VMPZM when a local coordinate frame is not active). $VMPXW, $VMPYW and $VMPZW refer to the linear LCS axes positions when the probe was triggered. $VMPLXW, $VMPLYW and $VMPLZW refer to the linear LCS axes positions at the start of the probe motion.

The $VMPRCOD Variable

$\textbf{{\char36}VMPRCOD}$

Probe cycle return code

Type: Numeric, Read/Write

When probing is active (set using the $FMSPROB function) the $VMPRCOD variable will be updated at the end of each model motion to indicate the status of the probe device (set using the $FMSPRID function). The following states are defined:

-1:

The probe device was already in a triggered state (i.e., already colliding) at the start of the motion. No probing data has been returned.

0:

The probe device was not triggered (i.e., did not collide) during the last motion. No probing data has been returned.

1:

The probe device was triggered (i.e., collided) during the last motion. $VMXFER contains collision status information.

2:

Same as #1 except that the probe device was triggered against two or more objects simultaneously.

The $VMTIME Variable

$\textbf{{\char36}VMTIME}$

Current simulation time

Type: Numeric, Read-only

The $VMTIME variable contains the current simulation time measured in seconds from the start.

The $VMTOLER Variable

$\textbf{{\char36}VMTOLER}\textbf{(}\mathit{n}\textbf{)}$

Simulation tolerances

Type: Numeric, Read-only

The $VMTOLER read-only array of length 4 contains the current Gouge, Collision, Faceting and Tool path tolerances.

1:

Gouge tolerance

2:

Collision tolerance

3:

Faceting tolerance

4:

Tool path tolerance

The $VMXFER Variable

$\textbf{{\char36}VMXFER}$

Collision/over-travel return code

Type: Sequence, Read/Write

The $VMXFER variable contains collision and over-travel event information resulting from the last model motion, including collision information resulting from a probe trigger event. $VMXFER is a sequence of length 7 as follows:

1:

The number of separate collision and/or over-travel events that occurred on the last motion. Zero if there were no collisions or over-travel events.

2:

The time at the start of the motion.

3:

The time at the end of the motion.

4:

The time at which the first collision or over-travel event occurred during the current motion. If $VMXFER(1)=0, then $VMXFER(4)=$VMXFER(3).

5:

The current feed rate in model units per minute or units per revolution. Zero if the motion was at rapid.

6:

The collision event number of a probe trigger, otherwise -1.

7:

The collision pair number of a probe trigger, otherwise -1.

When probing is active (set using the $FMSPROB function), and the probe was triggered (i.e., $VMPRCOD>0), then information about the object that was touched by the probe can be obtained by calling:
$FMSPDAT($VMXFER(6),$VMXFER(7))