Computer Drive Installation Instructions

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Siemens AG 2001 All Rights Reserved 6FC5197–jAA50
9–62
SINUMERIK 840C (IA)
In special cases, however, it may still be necessary to re-parameterize the error
measuring times:
S Setting of very extreme values for the compensation time constant (NC-MD
12360).
Experience shows that error measuring times of <10 ms and >200 ms are not
effective.
If a value of more than approximately 30 ms is set in NC-MD 12360, then the
setting in NC-MD 13700 (t
M1
) should be reduced in any case, and possibly
also the other error measuring times if appropriate.
If a value of less than approximately 5 ms (but not 0, see above) is set in NC-
MD 12360, then the setting in NC-MD 13800 (t
M1
), and possibly the other er-
ror measuring times as well, should be increased.
S Parameterization of measuring times when DT1 time constant is adapted
(NC-MD 18120, bit 2 = 1).
If the adaptation function for the DT1 time constant is used, then the following
rule of thumb applies to the parameter settings of error measuring time t
M1
:
t
M1
must be set to approximately 3 times the value in NC-MD 13640.
Example A value of 10 ms is parameterized in NC-MD 12360 and a value of 30 ms in
NC-MD 13640. With the default value from NC-MD 13720 of 600 %, an error
measuring time tM1 of 60 ms is thus calculated. However, the rule of thumb dic-
tates that a t
M1
of 90 ms must be applied and NC-MD 13720 must therefore be
set to 900 %.
Notes The error measuring time is required to produce the error criterion of the neural
quadrant error compensation function. This error criterion is also made available
under the Circularity Test in display Service QEC in order to facilitate parameter-
ization of the conventional quadrant error compensation function.
To ensure that the error criterion produces useful results, the error measuring
time should be parameterized even when the neuronal QEC is deselected (NC-
MD 18120, bit 0 = 0). NC-MD 13760 is provided for this purpose. NC-MD 13760
need only be re-parameterized for the decay time parameter settings (NC-MD
12360) described under the compensation time constant.
These 3 machine data are monitored or limited as follows:
S Service number 328 is output if NC-MD 13760 is set to 0 when the neural
QEC is activated via its machine data bits. This does not result in an error
message output with the conventional QEC.
S If the setting in NC-MD 13700 is lower or equal to the value in NC-MD 13760,
then the error measuring time in range 1 (in diagram above: a < a1) remains
constant at the error measuring time value from NC-MD 13760.
S If the setting in NC-MD 13800 is higher or equal to the value in NC-MD 13760,
then the error measuring time in range 3 (in diagram above: a > a2) remains
constant at the error measuring time value from NC-MD 13760.
9 Drive Servo Start-Up Application (as from SW 3)
9.5.4 Neural quadrant error compensation (QEC – SW 4)
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