In this subsection, the variables necessary to make effective use of the automatic gauging functions are described
5-5-1. Table of Subprograms and Variables
Subpro-gram Name
Variables for which Numerical Value Must be Set
Variables for which Numerical Value Should be
Set as Needed
Variable which Must not
be Used Datum Hole Zero
Point Setting
OO21 None VNUM: Gauging cycle
num-ber of datum Z-end face Approximate touch probe length offset data
Inner Diameter Does not cause alarm stop on occur-rence of excessive error
Undertravel distance Overtravel distance Probe single touch Second gauging not executed Numerical Value Must be Set
Variables for which Numerical Value Should be
Set as Needed
Variable which Must not
be Used
Outer Diameter
Infeed direction feed distance (PZIN) Does not cause alarm stop on occur-rence of excessive error
Undertravel distance Overtravel distance Probe single touch Second gauging not executed
Permissible error of X-end face position Does not cause alarm stop on occur-rence excessive Numerical Value Must be Set
Variables for which Numerical Value Should be
Set as Needed
Variable which Must not
be Used
End face gauging
Permissible error of Y-end face position Does not cause alarm stop on occur-rence of excessive error
End face gauging (Z-axis)
Permissible error of Z-end face position Does not cause alarm stop on occur-rence of excessive error Numerical Value Must be Set
Variables for which Numerical Value Should be
Set as Needed
Variable which Must not
be Used
Gauging cycle for between two end faces
Does not cause alarm stop on occur-rence of excessive error. Gauging cycle for
calculating the between two end faces
Does not cause alarm stop on occur-rence of excessive error. Numerical Value Must be Set
Variables for which Numerical Value Should be
Set as Needed
Variable which Must not
be Used
Saving the
Saving the X-axis data
Saving the Y-axis data
Saving the X-/Y-axis data
Saving the Z-axis data
Saving the X-/Z-axis data
Saving the Y-/Z-axis data
Saving the X-/Y-/Z-axis data
Gauging cycle for calculating the
Calculation on the X-axis
Calculation on the Y-axis
Calculation on the X-/Y-axis
Calculation on the Z-axis
Calculation on the X-/Z-axis
Calculation on the Y-/Z-axis
Calculation on the X-/Y-/Z-axis position error - X Anticipated distance - X-X
Permissible dis-tance error - X-X Anticipated center position - Y
Permissible center position error - Y Anticipated distance - Y-Y
Permissible dis-tance error - Y-Y Anticipated center position - Z
Permissible center position error - Z Anticipated distance - Z-Z
Permissible dis-tance error - Z-Z Does not cause alarm stop on occur-rence of excessive error. Numerical Value Must be Set
Variables for which Numerical Value Should be
Set as Needed
Variable which Must not
be Used
5-5-2. How to Use Variables
(1) PMOD (P MODE)
Designates the automatic gauging mode.
(2) PDI (P DIAMETER IDEAL VALUE)
Sets the anticipated diameter in the ID/OD gauging cycles.
(3) PDE (P DIAMETER ERROR LIMIT)
Sets the permissible error of the diameter for the ID/OD gauging cycles as an absolute value.
The hole dia. error over alarm occurs if:
PDE < | PDl - (Actual measured value of the diameter) |
The value obtained from the measurement in the X-axis direction is used as the actual mea-sured value.
With the horizontal spindle of the MCM, the value measured in either the X- or Y- axis direction is used as the actual measured value.
The measured diameter is not evaluated if PDE is not set. In this case, the result of judgment is always OK.
(4) PCE (P CENTER ERROR LIMIT)
Sets the permissible error of the center position of a circle as an absolute value for ID/OD gaug-ing cycles.
The X-axis permissible error, the Y-axis permissible error and Z-axis permissible error cannot be set individually.
The excessive off-center alarm occurs when,
PCE < | (Anticipated center of X-axis) - (Actual measured center of X-axis) | PCE < | (Anticipated center of Y-axis) - (Actual measured center of Y-axis) |
PCE < | (anticipated center of Z-axis) - (actual measured center of Z-axis) | (for MCM horizontal spindle) number for which zero point is offset X coordinate value after zero offset Y coordinate value after zero offset Z coordinate value after zero offset
None
PMOD Setting Gauging Mode
1 End face gauging cycle (X-axis)
2 End face gauging cycle (Y-axis)
3 End face gauging cycle (Z-axis)
6 OD gauging cycle
7 ID gauging cycle
8 Touch probe length offset
9 Touch probe radius compensation
14 Calculation of center and distance between two points
15 Saving of the measurement results
Subpro-gram Name
Variables for which Numerical Value Must be Set
Variables for which Numerical Value Should be
Set as Needed
Variable which Must not
be Used
The anticipated centers of the X-, Y- and Z-axis are the actual positions of the X-, Y- and Z-axis when the ID/OD gauging subprograms are called during the execution of a part program.
Error in the measured center position is not evaluated if PCE is not set.
(5) PIN (P IN)/PZIN (P Z IN)
Sets the Z-axis direction infeed distance as a relative value (positive incremental amount) for the OD gauging cycle
(6) PEI (P EDGE IDEAL VALUE)
Sets the end face position of the gauging target for the X-, Y- and Z-axis end face gauging cycles and the touch probe length offset cycle.
(7) PEE (P EDGE ERROR LIMIT)
Sets the permissible error of the end face position for an end face gauging cycle.
The excessive off-center alarm occurs when, PEE< | PEI - (Actual measured value of end face) |
Error in the measured end face position is not evaluated if PEE is not set.
(8) PUDT (P UNDER TRAVEL)
Sets the undertravel distance as an absolute value.
During the execution of a gauging cycle, the touch probe moves to a position a certain amount away from the anticipated contact detection position at a fast feedrate. This amount is set using PUDT.
If no value is set for PUDT, the undertravel distance is automatically set at 10 mm.
The gauging impossible alarm occurs when the touch probe comes into contact with the work-piece while it is advancing at a fast feedrate up to this position. If an occurrence of this error is suspected, PUDT should be set. Usually, set a value larger than 3 mm.
For the designation of PUDT, see examples 1 to 4.
(9) POVT (P OVER TRAVEL)
Sets the overtravel distance as absolute values.
During the execution of a gauging cycle, the touch probe moves to a position PUDT away from the anticipated contact detection position at a fast feedrate. After this positioning, the touch probe moves to a position a certain amount beyond the anticipated contact detection position at a medium-fast feedrate. This amount is set using POVT.
If no value is set for POVT, the overtravel distance is automatically set at 10 mm.
The gauging impossible alarm occurs when the touch probe fails to contact the workpiece even on reaching the position determined by POVT. If an occurrence of this error is suspected, POVT should be set.
For the designation of POVT, see examples 1 to 4.
CAUTION
Since the touch probe stops when it comes into contact with the workpiece, setting a large value for POVT will generally not cause a problem. However, it could cause the touch probe unit to strike the workpiece if a contact signal is not output due to the failure of the touch probe itself.
When an axis movement command larger than the touch probe stylus stroke is set, the touch probe will be damaged if the contact signal is not output due to the failure of the touch probe itself.
Therefore, do not set an unnecessarily large value for POVT.
Example 1: PUDT and POVT not designated
If PUDT and POVT are not designated, 10 mm is automatically set as the under-travel and overunder-travel distance.
Example program:
CALL OO10 PMOD=1 PEI=40
ME61012R0700400400001
ME61012R0700400400002
ME61012R0700400400003
[Supplement]
Example 2: Only POVT designated Example program:
CALL OO10 PMOD=1 PEI=40 POVT=2
Example 3 Only PUDT designated (PUDT = 15) Example program:
CALL OO10 PMOD=1 PEI=40 PUDT=15
Determine the PUDT value taking into consideration the allowable over-stroke of the touch probe.
Example 4: Both POVT and PUDT designated (POVT = 5, PUDT = 15) Example program:
CALL OO10 PMOD=1 PEI=40 POVT=5 Anticipated
position Actual
position
Touch probe stops if contact signal is not output.
X40 X43 X50
POVT=10 PUDT=10
X30
Touch probe stops if contact signal is not output.
Set so that this distance is smaller than the allowable over-stroke of the touch probe.
X42 X40
X35 X30
POVT=2 7mm
PUDT=10
Touch probe stops if contact signal is not output.
X50 X40
X30 X25
PUDT=15 POVT=10
ME61012R0700400400004
(10) PMSR (P MEASURE)
Usually, contact detection is executed two times in the X-axis direction when an ID/OD gauging cycle is executed. If “PMSR = 1” is set, however, the second contact detection cycle is not exe-cuted.
When the touch probe is set in the horizontal spindle of MCM, the second contact detection cycle in the X or Y-axis direction is not executed.
(11) PMTR (P MEASURE THREE)
When PMTR=1 is specified in ID or OD gauging cycle, the system measures the diameter only by gauging at X+, X-, and Y+ points. (For MCM Horizontal Machining Center, the system mea-sures the diameter only by gauging at Y+, Y-, Z+ points or X+, X-, Z+ points.)
Although the gauging time with the PMTR command is shorter that with the PMSR command, there is a little tendency to cause a gauging error.
(12) PTCH (P TOUCH)
Usually the touch probe touches the workpiece twice (second approach and third approach). If PTCH=1 is specified, however, the probe touches the workpiece only once (third approach) to measure the diameter. To set the approach speed for this gauging, specify PF3=**.
[Supplement]
(13) PQIK (P QUICK)
There is a time lag after the sub program OO10 is called until the touch probe starts moving toward the workpiece. This time lag can be a little reduced by specifying PQIK=1.
[Supplement]
(14) PDWL (P DWELL)
Set the dwell time in seconds used when the touch probe comes into contact with the work-piece.
The dwell is needed in the following three cases:
- At the 1st touch by the touch probe
- At 0.5-mm retraction of the touch probe after the 1st touch
Depending on the PUDT value, designation of PTCH command may prolong the gauging time.
Note that the gauging accuracy decreases if the PF3 value is too large.
Note that there are following restrictions on use of PQIK=1.
•In manual interruption, X, Y, Z-axis shift amount (total) are all cancelled.
•The command is usable only when the probe direction is the same with the vertical spindle.
•The command is usable only for an FM type or optical probe.
•The variable unit setting (0.001 mm or 0.0001 inch) to be transferred to MSB becomes invalid.
(NC optional parameter bit No. 36, bit 0)
Touch probe stops if contact signal is not output.
X45 X40
X35 X25
PUDT=15 POVT=5
- At the 2nd touch by the touch probe
These three times of dwells can be set with the command PDWL=** in calling a subroutine.
Without PDWL command, all the dwells are set to 0.5 second.
[Supplement]
(15) PGO (P GO)
• When “PGO = 1” is set, an alarm does not occur if the results obtained from the gauging cycle exceed the permissible range. When “PGO = 1” is set, judge the results of gauging (OK/NG) in a part program by reading system variable VOK1 after the completion of an automatic gauging subprogram.
“VOK1 = 0” when the result is OK.
• Another system variable, VOK2, is also used for storing the result of the gauging cycle. Dif-fering from system variable VOK1, which holds the result of the dimension check cycle executed immediately before its designation, VOK2 indicates, if “VOK2 ≠ 0”, an occurrence that the result of any one of dimension check cycles has exceeded the permissible error in all of the dimension check cycles executed after VOK2 has been reset to 0 (VOK2 = 0).
• In the case of the gauging impossible alarm, zero offset impossible alarm, command miss-ing error alarm or no subprogram function alarm, the CNC is alarm-stopped even if “PGO = 1” is set.
When PGO is not set, the CNC is alarm-stopped when the gauging cycle results have exceeded the permissible error also.
ME61012R0700400400005
With the program above, the diameter of the hole finished by boring operation is measured (N24). If the hole diameter is within a specified range (φ79.95 to φ80.05 mm), the machin-ing cycle is continued. If the diameter is larger than φ80.05 mm, the workpiece is deter-mined defective and the machining cycle is halted.
If the diameter is smaller than φ79.95 mm, execution of the program is interrupted by the M0 command in N27. This allows the operator to adjust the boring bit, to carry out the bor-ing cycle on the same hole again.
(16) VNUM (V NUM BER)
Sets the gauging cycle number (range: 0 to 9999).
Before the execution of an ID/OD gauging cycle, touch probe length offset, or touch probe radius compensation cycle, the present VNUM value is increased by “1” and the new number is printed as the gauging cycle number
The above three dwell times cannot be set independently.
Program example with "PGO = 1" setting .
.
N24 CALL OO10 PMOD=7 PDI=80 PDE=0.05 PGO=1... ID gauging
N25 IF [VOK1 EQ 0] N29 ... Jumps to N29 if the result is OK.
N26 IF [VC930 GT 80000] N100... Jumps to N100 if the diameter is greater than φ80.05 mm.
N27 M0
N28 GOTO N18 ... Re-machining N29 M6
N30 T10
N31 G0 X140 Y0 .
.
Once designated, VNUM is automatically increased by “1” at each execution of a gauging cycle to be printed.
When the gauging cycle number increases one by one and reaches 10000, the counter is reset and “0” is printed. Then, the number increases one by one from “0” in the same way as explained above.
(17) PAXI (P AXIS)
Sets the target axes for saving the gauging cycle results or for calculating the center and dis-tance between two points.
(18) PHN (P H NUMBER)
Sets the work coordinate system number for which zero offset is executed using the automatic zero offset function.
When PHN is not set, this results in a command missing alarm.
(19) PX, PY, PZ
These variables set the coordinate values that the actual position should take after offsetting of the zero point by the automatic zero offset function.
Set the coordinate value only for the axes on which zero offset is required.
For the undesignated axes, the zero offset data remains unchanged.
(20) PXCI (P X CENTER IDEAL VALUE)/PYCI (P Y CENTER IDEAL VALUE) /PZCI (P Z CENTER IDEAL VALUE)
These variables set the anticipated values of the center between two points (X-X, Y-Y, Z-Z) in the calculation of the center/distance between two points.
When these values are not set, the center position obtained as the result of a gauging cycle result is not evaluated.
(21) PXCE (P X CENTER ERROR LIMIT)/PYCE (P Y CENTER ERROR LIMIT) /PZCE (P Z CENTER ERROR LIMIT)
These variables set the permissible errors in the position of the center between two points (X-X, Y-Y, Z-Z) in the calculation of the center/distance between two points. Designate absolute val-ues.
When these values are not set, the center position obtained as the result of a gauging cycle is not evaluated.
(22) PXLI (P X LENGTH IDEAL VALUE)/PYLI (P Y LENGTH IDEAL VALUE) /PZLI (P Z LENGTH IDEAL VALUE)
PAXI Setting Target Axes
1 X-axis
Example: The procedure for offsetting the zero point of work coordinate system No. 2 so that the center of an inner diameter will have the coordinate values X = 10, Y = 50 is described below.
- Execute the ID gauging cycle.
- Execute the following program.
CALL OO20 PHN=2 PX=10 PY=50
These variables set the anticipated distances between two points (X-X, Y-Y, Z-Z) in the calcula-tion of the center/distance between two points.
When these values are not set, the distance between two points obtained as the results of a gauging cycle result is not evaluated.
(23) PXLE (P X LENGTH ERROR LIMIT)/PYLE (P Y LENGTH ERROR LIMIT) /PZLE (P Z LENGTH ERROR LIMIT)
These variables set the permissible errors in the distances between two points (X-X, Y-Y, Z-Z) in the calculation of the center/distance between two points. Designate absolute values.
When these values are not set, the distance between two points obtained as the results of a gauging cycle result is not evaluated.
(24) PE (P ERROR)
For the designation of the cycle to calculate the center/distance between two points, if the same value is assigned to permissible error values of the center position and the distance, variable PE can replace the designation of PXCE, PYCE, PZCE, PXLE, PYLE and PZLE.
The following two programs have the same effect.
PXCE=0.01 PYCE=0.01 PZCE=0.01 PXLE=0.01 PYLE=0.01 PZLE=0.01 PE=0.01
Note that PE is given priority over PXCE, PYCE, PZCE, PXLE, PYLE and PZLE. Therefore, take care when using PE with other variables.
If the setting is, for example, as indicated below PE=0.01 PZCE=0.02 PZLE=0.03
it is the same as
PE=0.01 PZCE=0.01 PZLE=0.01 (25) PELI (P EDGE LENGTH IDEAL VALUE)
Sets the anticipated distance between two faces.
(26) PELE (P EDGE LENGTH ERROR LIMIT)
Sets the permissible error between the distance set for PELI and the actual measured value.
5-5-3. Common Variables for Storing Gauging Cycle Results
After the execution of an automatic gauging cycle, the obtained results can be checked by display-ing the GAUGING RESULTS screen. In addition to this check, the results can be used in a part pro-gram to control propro-gram flow and other processing since they are stored in the common variables indicated below.
Note that referencing of the common variables indicated above is not allowed in the usual common variable reference method. To use the data stored in these common variables, move it to other com-mon variables that can be referenced.
To reference the end face gauging result in the X-axis direction, move the data to VC1, for example, by specifying “VC1 = VS29”, then read common variable VC1 in a part program.
[Supplement]
Type of Gauging Cycle
Common
Variable Type of Gauging Cycle Common Variable
ID gauging: Center (X)
ID gauging: Center (Y)
ID gauging: ID
VS29
VS28
VS30
Data saving: X-axis data
Data saving: Y-axis data
Data saving: Z-axis data
VS26
OD gauging: Center (X)
OD gauging: Center (Y)
OD gauging: OD
VS29
VS28
VS30
Center between two points (X)
Center between two points (Y)
Center between two points (Z)
VS29
VS28
VS27
— —
When the CNC is reset or the operation mode is changed to manual after the execution of a gauging cycle, the data obtained in this gauging cycle is cleared. In this case, it is necessary to execute the gauging cycle again.