Siemens 6DR2410, Руководство пользователя

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Manual 1 Technical Description
1.5 Functional Description
1.5.8 Complex Functions (Arithmetic blocks c, d, h)
SIPART DR24 6DR2410
C79000-G7476-C153-03
85
controlled variable during this time. Otherwise an error message is output with abortion of
the identification (see chapter 3.3.2, Table 3-2, page 143).
The step response of the controlled system is then accepted with a max. 84 value pairs
(time and amplitude). If the controlled variable x used for the adaptation is filtered (e.g. to
suppress noise level), it should also be used for external formation of the control differ-
ence with the same time behavior; otherwise the adaptation could be faulty. The filters
must be set accordingly in the adaptation. The measured values are read in with a scan-
ning rate according to the cycle time. The storage procedure operates with cyclic data
reduction and subsequent refilling so that slow controlled systems can be entered.
After the start identification has run, (the controlled variable x must have left the start
identification band within 50 % of the set monitoring time tU), 95 % of the end value must
be reached at
2
/
3
of tU at the latest. The set monitoring time (tU) must be
≥
2 T95 of the
controlled system with safety reserve. The remaining time is required for the end value
identification. The end value identification can also take place immediately after the start
identification, but
1
/
3
of the performed measurements are always required for the end
value identification. Recording of the measured value pairs is ended on identifying the
end value.
A comparison with the recorded transient function is now made based on the stored Ptn
models with n = 1 to 8 and equal time constants T by variation of n and T. The deter-
mined line gain ks is transfered to the line models. The comparison is made over the
minimum error area F (n, T).
Additionally a special entry of real dead times is made which then shifts the identified
control line to higher orders.
Controlled lines with compensation and periodic transient of 1st to 8th order with a tran-
sient time T95 of 5 s to 12 h can be identified. Dead time parts are permissible. In S--con-
trollers the transient time T95 should be twice the positioning time Ty.
Error checks are made during line identification in order to be able to prematurely abort
the identification. There are 11 control steps altogether which are displayed by flashing on
the digital x- and w- indicators when errors occur. As soon as an error message appears,
the line identification is aborted and it must be restarted after correcting the presettings in
the parameterization mode AdAP if necessary. Acknowledgement or listing of the error
messages, see chapter 3.3.2, Table 3-2, page 143).
- Controller design
The controller is designed according to the method of amount optimum. This setting
method is very robust and also allows variation of the line amplification. However, it gen-
erates an overshoot of approx. 5 % in the event of changes in the command variables.
The controller is designed for PI and PID behavior, therefore kp, tn and for PID tv are cal-
culated, whereby the derivative gain is fixed at 5. The prerequisite for the effect of the
differential part is that the D element is switched with xd. To determine the parameter Tv,
tv must be
≠
oFF (onPA).
In S--controllers the response threshold AH is calculated in addition to kp, tn, tv. The pa-
rameters tA, tE and tY must be set according to the used actuating drives beforehand. If
the transient time T95 is close to 2 tY (positioning time) overshoots may also be gener-
ated in controller designs with D-part.