Siemens SINUMERIK 840C - Manual (Page 674)

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Siemens AG 2001 All Rights Reserved 6FC5197– j AA50 9–53
SINUMERIK 840C (IA)
D Standard start-up QEC
Explanation The start-up process is semi-automatic and does not involve any external equip-
ment. The contour accuracy achieved can be checked by means of the circularity
test implemented internally in the control or with the aid of external measuring
equipment. The standard start-up procedure is described and explained below.
The functions provided to assist start-up as well as additional parameterization
options in the event of unsatisfactory results are also given.
Decay time setting The optimum decay time (NC-MD 12360) is determined manually at an operating
point; the procedure to follow is described in section “Friction compensation”. The
integrated circularity test is provided to assist calculation of this setting (see sec-
tion headed “Circularity test”). The default settings of NC-MD 12360 (15 ms) en-
sure good results. The decay time is generally constant over the entire operating
range. In special cases, however, it may be advantageous to raise the setting in
the very low acceleration range or vice versa, to reduce the setting for very high
acceleration rates (see section headed “Further optimization and intervention
options”).
Loading of standard A file (STANDD_Q) containing standard data is available on the MMC for the
parameters parameters described under the Function parameters softkey; its purpose is to
facilitate the start-up procedure. The start-up engineer can load these data by
selecting softkey File functions or he can, as an alternative, enter the parame-
ters individually.
The value for parameter “Max. acceleration” must be entered according to re-
quirements, i.e. the neuronal network works and learns optimally only in the oper-
ating range with this maximum acceleration value.
Note: When these parameters are entered manually, they do not become operative as
working data until the Parameter transfer softkey has been selected.
When one of the function parameters is changed by means
of the Parameter transfer softkey, the working data
(SERVO) are overwritten with the initialization value. The
saved characteristics (files on MMC) are not affected.
Activation of neural The neural QEC is activated for the desired axis by setting bit 0
quadrant error of NC-MD 18120. If the function parameters in the working data are not
compensation meaningfully assigned at the instant of activation, then service number 328 is set
(see start-up lists).
Learning process This process trains the network. For this purpose, a test signal is generated on
the basis of which the network learns the optimum compensation amplitude over
the entire parameterized operating range.
9 Drive Servo Start-Up Application (as from SW 3)
9.5.4 Neural quadrant error compensation (QEC – SW 4)
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