Dfr (D Flip-Flop, Reset Dominant); Bsw (Binary Change-Over Switch) - Siemens Sinamics S110 Function Manual

Drive functions
7.3 Function modules
7.3.8.18

DFR (D flip-flop, reset dominant)

Brief description
BOOL-type function block for use as a D flip-flop with reset dominance
Mode of operation
If inputs S and R are logical 0, the D input data is switched through to output Q when a rising
edge is present at trigger input I.
Output QN always has the opposite value to Q. With logical 1 at input S, output Q is set to
logical 1.
If input R is set to logical 1, output Q is set to logical 0. If both inputs are logical 0, Q does
not change.
If inputs S and R are logical 1, however, Q is logical 0 because the reset input dominates.
Time flow chart
Output pulse Q as a function of the D input and input pulse I for S = R = 0.
I
D
Q
Q N
Figure 7-77
7.3.8.19

BSW (binary change-over switch)

Brief description
This function block switches one of two binary input variables (BOOL type) to the output.
Mode of operation
If input I = 0, I0 is switched to output Q.
If input I = 1, I1 is switched to output Q.
310
1
0
1
0
1
0
1
0
DFR (D flip-flop, reset dominant): Time flow chart
Function Manual, 01/2011, 6SL3097-4AB10-0BP3
Function Manual