Measuring Circuit Monitoring And Alarm Processing; C Axes To Spindles - Siemens SINUMERIK 840C Installation Instructions Manual

12.93
12.15.3
• The functions pulse code monitoring and zero monitoring are either active or inactive for
both measuring systems (selection made via MD 1820*, bit 1 and 6).
If an error is detected in one of the two measuring systems, the associated alarm is
triggered (alarm 140* "Pulse code monitoring", alarm 144* "Zero mark monitoring").
They are acknowledged with the RESET keys.
• The absolute encoder error alarm 1040* "Absolute encoder defective" and alarm 1044*
"Battery absolute encoder submodule" are also triggered irrespective of the measuring
system currently active.
• Measuring circuit monitoring for alarm 132* "Control loop hardware axis" and alarm 136*
"Contamination measuring system" are only active for the active measuring system. This
makes it possible to change the encoder on the inactive measuring system without having
to carry out a warm restart of the control. If one of these errors still exists when the other
measuring system has been selected, the alarm in question is triggered.
12.15.4
For the function C axes to spindles, the second measuring system has a different definition.
Here the first measuring system is the axis measuring system parameterized in MD 400*. The
second measuring system is defined in MD400* via the spindle machine data. Any additional
second measuring system defined in the axis machine data is ignored.
The measuring system parameterized in MD 200* (first) is permanantly assigned to a spindle
with C axis for C axis operation, the second measuring system is used for the spindle
operating modes and must be parameterized with MD 400*. C axis/spindle are assigned in
MD 461*.
Control bit "Measuring system 1/2" in DB32 can also be used for C axes, however the
switchover tolerance MD 1216* has no effect. If the control signal is kept to "1", the mode
controlled measuring circuit switchover spindle C axis measuring system is disabled. This
means that
• if a reference point approach is executed with the C axis, synchronization is with the
precision of the spindle encoder,
• the limit frequency of the spindle encoder remains active, i.e. C axis mode with higher
feedrate is possible.
The spindle encoder (MD 400*) is always used in the spindle modes, i.e. the switchover signal
only effects C axis mode.
If different encoders are being used for spindle and C axis mode, please ensure that the
control directions of the axis and spindles are parameterized in the same direction of rotation in
MD 564*,
cannot be ascertained by the system software from the MD bits. The spindle direction of
rotation can be reversed from the PLC with the interface signal "Invert MD 3/4".
For backlash compensation and lead screw error compensation the following applies: if spindle
and C axis encoder are different, backlash compensation and lead screw error compensation
are only active in C axis mode (for first measuring system), if identical encoder definitions have
been entered for the spindle and C axis, backlash compensation and lead screw error
compensations are active in the position control mode M19 (M19 absolute, M19 through
several revoltions) and C axis mode.
© Siemens AG 1992 All Rights Reserved
SINUMERIK 840C (IA)
More user manuals on

Measuring circuit monitoring and alarm processing

C axes to spindles

1 and bit 2 and MD 520*, bit 1 and MD 521*, bit 1. The correct parameterization
Bit
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12.15.3 Measuring circuit monitoring and alarm processing
6FC5197- AA50
12 Functional Descriptions
12–117