Online Tool Offset; Function - Siemens SINUMERIK 840D sl Function Manual

W4: Grinding-specific tool offset and tool monitoring

18.2 Online tool offset

18.2 Online tool offset
18.2.1

Function

A grinding operation involves both machining of a workpiece and dressing of the grinding
wheel. These processes can take place in the same channel or in separate channels.
To allow machining to continue while the grinding wheel is being dressed, the reduction in the
size of the grinding wheel caused by dressing must be transferred to the current tool in the
machining channel as a tool offset that is applied immediately. This can be implemented by
means of the "Online tool offset" function.
Figure 18-8
The function supports the following methods of writing the tool offset:
● Continuous write, non-modal (PUTFTOCF (Page 859))
With PUTFTOCF, dressing is carried out at the same time as machining.
The tool offset is changed continuously in the machining channel according to a polynomial
function of the first, second or third order, which must have been defined previously with
FCTDEF (Page 857).
PUTFTOCF is always non-modal; in other words, it takes effect in the subsequent traversing
block.
● Continuous write, modal: ID=1 DO FTOC (for further information, see Function Manual
Synchronized Actions)
● Discrete write (PUTFTOC (Page 860))
With PUTFTOC, dressing is not carried out at the same time as machining from a parallel
channel. The correction value specified with PUTFTOC takes effect immediately in the
destination channel.
Activation / deactivation
The online tool offset in the part program is activated/deactivated by means of the G command
FTOCON/FTOCOF (Page 860).
856
Dressing during machining using a dressing roller
Function Manual, 10/2015, 6FC5397-1BP40-5BA3
Extended Functions