Siemens Sinumerik 840D Operating Turning page 83

Further zero point offsets
For the efficient production of parts it is often sensible to provide several
work piece zero points.
The control unit manufacturer provides for up to 99 selectable zero point
offsets.
Note:
Depending on the machine parameters this number can be set differently.
Please refer to the machines manual regarding the exact number of avail-
able zero points.
Further zero point offsets
The application example indicates the use of yet another zero point located
on the setting plane of the chuck.
In the picture below the work piece zero point has been transferred with
G55 exactly to the setting plane of the chuck jaws.
In the program this must be activated by means of the code G55.
The use of several zero point offsets can substantially reduce the setting
times particularly in cases of one-off or small series machining.
For example: You could define just once a specific setting point for each
one of your clamping fixtures or else a specific work piece zero point for
various work pieces.
In the program the respective zero point offset depending on the clamping
fixture or the work piece can then be selected.
If an identical work piece is to be machined at a later time, the respective
zero point is immediately available under the same code.
Important:
Zero point offsets are stored in the non volatile memory of the control unit.
Zero point offset instructions or commands are MODAL COMMANDS .i.e.
once executed they remain active until they are deactivated with different
set of commands.
840D/828D SINUMERIK Operate
Codes G55, G56 and G57
Codes G505 to G599
(all stated codes are
modally operative)
Setting face of the chuck jaws.
The left planar face of the work
piece is already machined.
W
(All work piece coordinates of the
longitudinal axis must be pro-
grammed in the positive direction)
Page 5
Section 4
Notes
B505
B505