Computer Drive Installation Instructions

09.95 6 NC Machine Data (NC MD), NC Setting Data (NC SD)
6.7 Axis-specific MD 2 (axial data 2)
Division reference dimension
1108*
Default value Lower input limit Upper input limit Units
0 0 99 999 999 units (MS)
Active
at once
Note:
The rotary axis has a defaulted internal reference dimension of 360 degrees in accordance
with the input resolution. No input is necessary.
When using the function in conjuction with chain-type magazines it may be necessary for the
rotary axis to perform several revolutions to arrive at one magazine revolution.
The division reference in this case will still be 360°. Adjustment of either the rotary axis or the
chain-type magazine can be carried out by variable increment weighting.
Division dimension offset
1112*
Default value Lower input limit Upper input limit Units
0 - 999 9999 99 999 99 units (IS)
Activ
see below
Remarks regarding the action of machine data:
If the use of the function is dependent on the workpiece, the machine data are changed while
the workpiece is being machined and in setup mode. This can be done by:
• MD modification from the PLC
• MD modification via configuration
• MD modification via CL 800
The machine data can be configured in such a way that they can be changed without start up
mode. They take effect immediately after change without, for instance, Warm restart or Reset
having to be performed.
If, for instance, the division machine data are changed while a division processing operation is
in progress, they will take effect after about only 100 ms.
Traversing an indexing axis to the reference point
If the function is used on a machine-specific basis, the indexing axis can be traversed to a
division-specific reference point. The MD ”Reference point offset” can be used to specify the
distance of the zero mark to an indexing position. The indexing axis need not be traversed to
an indexing position using the reference point. The next traverse of the axis after reference
point approach is automatically a movement to an indexing position.
Example:
Linear axis: Number of divisions = 5
Division reference dimension = 200,000 µm
Reference point = 140,000 µm;
Reference point offset = 0;
illegal
area
140,000 µm
200,000 µm
µm
6
1
2 3 4 5
© Siemens AG 1992 All Rights Reserved 6FC5197- AA50 6–159
SINUMERIK 840C (IA)