Controllers
Parameter manual
b maXX
BM3000
Document no.: 5.12001.07
Baumüller Nürnberg GmbH
508
4.7
4.7.5.3 Two-level controller with relative thresholds
In this operating mode the actual value two-level controller is compared with an upper and
lower switching threshold, which is calculated from the momentary value of the parameter
number
Relative compare value. Therefore the switching point is not a definite
value, but follows the momentary value, which parameter number is specified in
Relative compare value.
Figure 169:
Two-level controller with relative thresholds
m
The switching hysteresis arises from the difference between the lower and upper
switching threshold.
m
The two-level-controller with relative thresholds is activated by bit 1 = 1 in parameter
mode two-level controller.
m
The two-level controller switches off, if the following is valid:
Two-level-controller input
Two-level-controller relative upper switching threshold
m
The two-level controller switches on, if the following is valid:
Two-level-controller input
Two-level-controller lower switching threshold
4.7.5.4 Combination of the operating modes absolute and relative thresholds.
Both threshold types can be activated commonly, in order to limit and monitor the behav-
ior of the relative threshold by a constant, absolute threshold controller.
t
h(t)
y
t
5000_0207_rev01_int.cdr
rel. lower threshold
rel. upper threshold
rel. compare value