Siemens SINUMERIK 840C - Manual (Page 639)

Meas.
parameter
09.95
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Siemens AG 2001 All Rights Reserved 6FC5197– j AA50 9–18
SINUMERIK 840C (IA)
D
3rd measurement type: Setpoint step change
The transient response of the speed control in the time range can be assessed
with the step stimulation function for setpoint or disturbance variables. If an off-
set value other than zero is input, the step change is stimulated during transition.
You can select the menu with the parameters for measuring the speed control
loop with this softkey.
Notes You enter the measurement parameters in the selected display. These parame-
ters are managed internally as configuration data rather than machine data, i.e.
they are not initialized when the machine runs up. Data can be input in two
different ways:
S
Manual input
S
Input by loading of an existing, complete data set with the aid of file functions
The recording starts with the output of the setpoint step, i.e. the step is not visible
in the setpoint signal display. This does not apply to analog drives because a
fixed pre-trigger time corresponding to 10 % of the measurement time is set for
them. If the settling time setting is lower than this 10 % value, then the pre-trigger
time is limited to the settling time.
Measurement
S
Amplitude
parameter settings This parameter determines the magnitude of the specified disturbance step
change.
S
Offset
The step is stimulated from standstill or starting from the constant traverse
speed set in this parameter.
As from SW 6:
S
The offset is reached along an acceleration ramp.
S
The acceleration value is defined for an
axis:
MD 276*: Acceleration
spindle: MD 419* –
MD 426*: Acceleration constant for 8 gear stages
S
The following applies: Acceleration value=0, no ramp
Acceleration value
y
0, ramp active
S
The actual measuring function is not activated until the offset value is re-
ached.
S
Measurement time
This parameter determines the period of time to be recorded.
S
Settling time
This value represents the delay between the start of measured data recording
and injection of the test signal and offset (not relevant for 611D).
Notes The recording starts with the output of the setpoint step, i.e. the step is not visible
in the setpoint signal display.
If the selected measurement cannot be carried out with the installed drive, the
dialog box 160007 Measurement/drive-type combination not allowed appears
when the Start softkey is selected.
9 Drive Servo Start-Up Application (as from SW 3)
9.2.4 Speed control loop (axis and spindle) – measurement parameters (4 basic settings – as from SW 3)
07.97