Siemens SINUMERIK 840D Description Of Functions page 126

4 Firmware Drive Functions
4.5 Output of manipulated variables
Linearization of
valve
MD 5485
MD 5464
MD 5468
MD 5480
–100%
MD 5488 MD 5484
Fig. 4-14 Valve characteristic with breakpoint in zero, fine control and saturation ranges
5480 POS_DUAL_GAIN_COMP_Z_FLOW
Knee-point compensation pos. flow in zero range
Unit: Default:
% 0.01
5481 POS_DUAL_GAIN_COMP_Z_VOL T
Knee-point compensation pos. voltage in zero range
Unit: Default:
% 0.0
4-126
SINUMERIK 840D/SIMODRIVE 611 digital Descr. of Functions HLA Module (FBHLA) – 04.00 Edition
Valves with a fine control range are described in Section 4.7. An inverse charac-
teristic is applied to compensate the nonlinear characteristic of these valves.
The breakpoint on real valves is rounded. For this reason, the breakpoint range
in the compensation characteristic is also rounded. The rounding is imple-
mented according to a root characteristic in such a way that the intersection
points lie on a continuous tangent; the rounding range can be parameterized.
Fig. 4-14 shows an example of this characteristic and the mode of action of the
associated machine data.
The knee point is defined by the percentage for input (voltage) and output
(flow).
Q
100%
MD 5481 MD 5486
MD 5483
MD 5465
MD 5467
MD 5487
–100%
S
Valve characteristic with breakpoint in zero range
Minimum: Maximum:
0.01 95.0
Minimum: Maximum:
0.0 95.0
U
MD 5466
100%
(positive/negative)
MD 5482
(positive/negative)
Relevant for:
HLA
Data type:
FLOAT
Relevant for:
HLA
Data type:
FLOAT
 Siemens AG 2000. All rights reserved
04.00
02.99
Cross ref.: –
Protection level:
3/3
Effective:
Immediately
Cross ref.: –
Protection level:
3/3
Effective:
Immediately