U Incremental value of the offset register - X-axis Y Absolute value of the offset register - Y-axis (if available) V Incremental value of the offset register - Y-axis (if available) Z Absolute value of the offset register - Z-axis
W Incremental value of the offset register - Z-axis R Absolute value of the offset register - tool nose radius C Incremental value of the offset register - tool nose radius Q Tool tip number for radius offset (imaginary tool tip number)
62
Chapter 5P-Offset Number
Note the com ment next to the P-ad dress - the P-ad dress rep re sents ei ther the ge om e try off set num ber or the wear off set num ber to be set. To dis tin guish be tween the ge om e try off set and the wear off set, the ge om e try off set num ber is in creased by an ar bi trary amount of 10000:
2 P10001
... represents the selection of geometry offset number 12 P10012
... represents the selection of geometry offset number 12If the 10000 value is not added, the P-ad dress rep re sents the num ber of the wear off set:
2 P6 ...
represents the selection of wear offset number 62 P11
... represents the selection of wear offset number 11The num ber of avail able off sets de pends on the con trol sys tem. For ex am ple, Fanuc 16/18/21 con trols have up to 64 off sets avail able.
Tip Num ber Q
The imag i nary tool tip num ber (some times called the vir tual tip num ber or just tip num ber) has been ar bi trarily de fined by Fanuc. For the rear type CNC lathes, the Fig ure 15 il lus trates the fixed num bers as signed to nine pos si ble tool tips:
The above tip num bers re fer only to the rear lathe type, as shown by the axis ori en ta tion sym bol.
DATA SETTING
63
T3 T7 T2
T4 T8
T5
Tool reference point Tool nose radius Tool tip number Tn
T0 or T9
T6 T1
X
Z
Figure 15
Tool nose tip numbers 0-9, programmed in the Q-address of the G10 command
G10 Offset Data Settings - Turning Examples
Data setting for lathe controls has a little dif fer ent struc ture, but the con trol sys tem pro cesses it with the same built-in logic. Typical ex am ples of off set data set ting for a CNC lathe are shown, along with ex pected re sults. The list ing is based on the or der of in put in the pro gram:
2 Ex am ple 1:
Block N10 will clear all ge om e try off sets for G 01 group (the ge om e try off set 1 register)
N10 G10 P10001 X0 Z0 R0 Q0
Block N20 will clear all wear off sets for W 01 group (the wear off set 1 register)
N20 G10 P1 X0 Z0 R0 Q0
+
Using Q0 in G10 block will cancel BOTH tool GEOMETRY and tool WEAR tip numbers2 Example 2:
Block N30 will set the con tents of G 01 group to X-200.0 Z-150.0 R0.8 T3. It will also set the tool tip num ber 3 in the wear group W 01 - au to mat i cally !
N30 G10 P10001 X-200.0 Z-150.0 R0.8 Q3
2 Ex am ple 3:
Block N40 will set the wear group W 01 tool nose ra dius to the value of 0.8, while the cur rent tool tip num ber 3 is still ac tive (not listed means not changed):
N40 G10 P1 R0.8 Cur rent tool tip num ber set ting IS as sumed
In pro fes sional pro gram ming, it is much safer to pro gram with out as sump tions of cur rent val ues and in clude the re quired tip num ber in the block, just in case - compare block N50 to N40:
N50 G10 P1 R0.8 Q3 Cur rent tool tip num ber set ting IS NOT as sumed
2 Example 4:
Block N60 sets the wear group W 01 to X-0.12, re gard less of its pre vi ous set ting:
N60 G10 P1 X-0.12
while the block N70 up dates the cur rent value of X-0.12 by the in cre ment of U+0.05, to the new off set reg is ter value of X-0.07:
N70 G10 P1 U0.05
64
Chapter 5Note that the tool tip num ber (pro grammed in the G10 ap pli ca tion as the Q en try) will al ways change the ge om e try off set and the wear off set si mul ta neously, what ever the value or the off set type is. There is a sim ple and very log i cal rea son for it - it is a con trol built-in safety that at tempts to elim i nate data en try er ror (man u ally or au to mat i cally). It is im pos si ble to have a dif fer ent ge -om e try and wear tool tip num bers for the same phys i cal tool. Data re lated to axes or the tool nose ra dius may have dif fer ent ge om e try and wear off set val ues, be cause they re late to di men sions.
Data Setting Check in MDI
Pro gram ming off set val ues through the stan dard or macro pro gram re quires full un der stand ing of the data in put for mat for a par tic u lar con trol sys tem. It is too late when an in cor rect set ting causes a dam age to the ma chine or the part. One way to make sure the off set data set ting is cor rect is to test it. Such a test is very easy to per form in the MDI (Man ual Data In put) mode of the con -trol sys tem. An sin gle word or the whole block can be en tered in the MDI mode to test the in put, be fore com mit ting the data into the pro gram. Se lect the Pro gram mode and the MDI mode at the con trol unit, then in sert the in put data to check - for ex am ple:
G90 G10 L10 P12 R-106.475 o Press INSERT
o Press CYCLE START
To ver ify the ac cu racy of the in put, check the tool length off set H12 - it should con tain the stored amount of -106.475. Still in the MDI mode, up date the pre set data - for ex am ple:
G91 G10 L10 P12 R-1.0 o Press INSERT
o Press CYCLE START
To ver ify the ac cu racy of the in put, check the tool length off set H12 again -it should con tain the stored amount of -107.475.
Other tests should fol low the same process. Al ways se lect the test data and off set num bers care -fully, so they can not cause any damage.
Programmable Parameter Entry
This sec tion cov ers yet an other as pect of pro gram ming the G10 data set ting com mand - this time as a modal com mand. It is used to change a sys tem pa ram e ter through the stan dard or macro pro gram. This application is some times called the ‘Write to pa ram e ter func tion’, and is not very com mon in ev ery day pro gram ming, even in macros. Be fore you at tempt to use this method, make sure you fully un der stand the con cept of con trol sys tem pa ram e ters sec tion, de scribed ear lier in this hand book - see pre vi ous chap ter for details.
DATA SETTING
65
Incorrect setting of CNC system parameters may cause irreparable damage to the machine tool
Typ i cal uses of the G10 com mand are com mon to changes of ma chine or cut ting con di tions, for ex am ple, spin dle speed and feed rate time con stants, pitch er ror com pen sa tion data, and oth ers.
This com mand often ap pears in the cus tom mac ros, nor mally called by the G65 com mand, and its sole pur pose is to con trol the ma chine op er a tions. The sub ject and de tailed ex pla na tion of the Cus -tom Mac ros and their struc ture is cov ered in the next chap ter - G10 is just a small item of the ba sic knowl edge be fore us ing mac ros.
Modal G10 Command
When the G10 com mand for the off set data set ting was first in tro duced in this chap ter, it had to be re peated in each block, if a se ries of set ting were re quired. By def i ni tion, G10 data set ting com mand for the en try of off sets can only be used as a nonmodal com mand. Mod ern Fanuc con -trols also al low to do an other type of data change through the pro gram - the change of the CNC sys tem pa ram e ters.
With out the ma chine user even know ing, many pro gram en tries are au to mat i cally con verted to var i ous sys tem pa ram e ters by the con trol unit. For ex am ple, if the pro gram con tains G54 work off set, its cur rent set ting can be found on the work off set screen. This dis play is for the op er a tor's con ve nience only the ac tual stor age of the off set amount takes place in a sys tem pa ram e ter, iden -ti fied by a pa ram e ter num ber, as as signed by Fanuc. Even if the G54 set -ting is changed man u ally, through the off set screen, or through a pa ram e ter change (us ing the proper pa ram e ter num ber), it is al ways stored in the sys tem pa ram e ter. Some pa ram e ters can not be changed as eas ily - some can not be changed at all the modal G10 com mand can be very use ful for chang ing sev eral pa -ram e ters at the same time. In fact, to achieve this goal, two re lated com mands are re quired - G10 to start the set tings and G11 to can cel the set tings:
G10 L50 Selecting parameter setting mode ON
... Data setting single block or a series of blocks (typical use)
G11 Selecting parameter setting mode OFF
The data set ting block for a pro gram ma ble pa ram e ter set ting has three en tries:
G10 L50
N.. P.. R.. Data setting block - more than one block is allowed between G10 and G11 G11
+
where …G10 Data setting mode - ON
L50 Programmable parameter entry mode (fixed)
N.. P.. R.. Data entry specification (N=parameter number, P=axis number, R=setting value) G11 Data setting mode - OFF (cancel)
Be tween the G10 L50 and G11 blocks is the list of pa ram e ters to be set, one per block. The pa -ram e ter num ber uses the N-ad dress and the data uses P and R ad dress re spec tively.