Monitoring; Actual Value Display - Siemens SINUMERIK 840C Installation Instructions Manual

12 Functional Descriptions

12.13.6 Monitoring

12.13.6 Monitoring
Monitoring reacts to illegal MD input values for division:
Permissible input values are:
• Number of divisions
• Reference dimension linear axis : 1 ... 99 99 999
• Offset
Otherwise alarm 1200* is triggered.
The monitoring function also checks that the number of divisions and the reference dimension
are not equal to 0 (for linear axes) with the indexing axis is selected. Otherwise alarm 1200* is
triggered.
If the axial MD bit "Software limit switch active" is set, the actual values of the indexing axis
are checked.
The monitoring checks to make sure that the axis is not a rounding axis. Otherwise alarm
1200* is set.
12.13.7

Actual value display

The actual values are displayed as divisions if the option "Indexing function" is set, the axis is
an indexing axis, the MD bit "Actual values division related" is set and the special actual
values PRESET offset, axis actual position or workpiece-oriented actual value are selected.
The actual values on the service display cannot be displayed as divisions.
• For rotary axes the calculation is modulo "Number of division". The division counter
counts from the initial value "1" to the end value ("Number of divisions") and returns to
"1" when it moves again.
• The calculation for linear axes is absolute. The division counter does not return to 1 after
crossing the end value but continues to count.
ND=7
1
7 2
6 3
5 4
Example: rotary axis
ND = Number of Divisions
• The system does not check whether the linear axis is in the illegal range. Undefined values
are used in the calculation (indexing position < 1 refers to the illegal range).
• The division counter
– can be read by the NC via the CL 800 (360
set)
– can be read by the PLC
– can be configured (with its own actual value display with division counter)
– cannot be written
12–110
: 1 ... 999
linear axis : +/- 1 ... 99 999 999
rotary axis : +/- 360 degrees
Illegal
range
1
Example: linear axis
when a division
,
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ND=7
2 3 4 5
related display has been
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SINUMERIK 840C (IA)
06.93
6 7 8
6FC5197- AA50