Siemens sinumerik 840D sl Function Manual page 208

Brief description
1.2 Programmable contour accuracy
Figure 1-1
As long as the calculated actual position of the tool tip remains inside the sketched tunnel,
motion continues in the normal way. If the calculated actual position violates the tunnel, an
alarm is triggered (in the default setting) and the axes are stopped by "Ramp Stop". This
response to the violation of the tunnel can be disabled (alarm triggered but movement
continued) or intensified (rapid stop) by means of a machine data setting.
Analysis
The calculated distance between the programmed path and the actual values can be routed
to an analog output to analyze the progression of the contour errors during normal operation
(quality control).
1.2 Programmable contour accuracy
Function
As an alternative to the function described in "Contour tunnel monitoring", i.e. monitoring of
the machining accuracy and stopping machining if excessive deviations occur, another
function is offered. With this function, the selected accuracy is always achieved with the path
velocity being reduced if necessary. Detailed information about this function can be found
under the subject "Programmable contour accuracy".
6
Position of the contour tunnel around the programmed path
Special functions: Contour Tunnel Monitoring (K6)
Function Manual, 11/2006, 6FC5397-2BP10-2BA0