Drive Parameter Group; Switchover - Siemens SINUMERIK 840C Installation Instructions Manual

10.94
• The function is disabled for measuring systems with distance-coded zero marks, i.e. a
gear ratio other than 1:1 must not be set for such axes. Incorrect MD settings generate the
alarm "Parameterization error NC-MD" and service alarm 312.
• In the case of axes, the gear ratio acts on the actual values from the 1st measuring
system.
• In the case of spindles/C axes, different gear ratios can be set for both operating modes,
even if only one encoder is defined. When the operating mode is switched over, the gear
ratio is automatically adapted.
• When the gear ratio changes after a parameter set switchover, the signal "Axis
referenced" or "Spindle synchronized" is reset (Note: A check is made to ascertain
whether the individual values for "Number of teeth, motor" and "Number of teeth, spindle"
are the same, i.e. internally, a gear ratio of 1:1 is not the same as a ratio of 2:2. This only
applies to the treatment of status signal "Axis referenced"/"Spindle synchronized" and has
no effect on actual value evaluation).
The status signals are also reset when the backlash compensation value is changed (by
means of parameter set switchover or MD change).

Drive parameter group

With SIMODRIVE 611A systems, parameter sets are switched over by means of terminals
which can be switched externally. The parameter sets (speed controller parameters, filter
settings, current and power limits, etc.) can be specified directly via the PLC-NCK interface
with SIMODRIVE 611D systems.
The switchover of a parameter set from a certain parameter group can be initiated, for
example, from the part program by means of an auxiliary function. This function is detected by
the PLC which subsequently passes the parameter set number to the NCK interface and
activates it.
12.27.3

Switchover

Switchover between parameter sets is implemented via the PLC interface:
Axis: Parameter group "Position control"
Parameter group "Ratio"
Parameter group "Drive 611D"
Spindle: Parameter group "Position control"
Parameter group "Ratio"
Parameter group "Drive 611D"
To ensure that switchover for the spindle is implemented by means of these interface signals,
MD 522*, bit 4 "Switch over parameter groups separately" must be set. In this case, the
interface signals for the actual gear stage (DB 31, DW K + 1, bits 0 - 2) are without meaning.
The display of the actual gear stage in the service display continues to be updated according
to the interface signals, but does not otherwise have any effect.
If the MD bit is not set, then the PLC signals for the actual gear stage are used.
In the case of spindles/C axes, the switchover behaviour of the spindle and the C axis is
influenced by MD bit 522*, bit 4, "Switch over parameter groups separately". "Separate
switchover" is a fixed setting for normal axes. It is possible to influence C axes via the spindle
MD bit such that all parameter groups ("Position controller", "Ratio" and "Drive) are switched
over together via the interface of the "Position controller" parameter group.
© Siemens AG 1992 All Rights Reserved
SINUMERIK 840C (IA)
12.27.2 Parameter set switchover with SW 4 and higher (option)
:DB 32, DW K+123, bits 0, 1, 2
:DB 32, DW K+123, bits 3, 4, 5
:DB 29, DW K+122, bits 0-1, 2
:DB 31, DW K+51, bits 0-1, 2
:DB 31, DW K+51, bits 3-4, 5
:DB 31, DW K+74, bits 0-1, 2
6FC5197- AA50
12 Functional Descriptions
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