Siemens SIRIUS 3RK3 - Flip-Flop; Ff-Sr

Description of the software
6.7 Functions
Modular Safety System 3RK3
System Manual, 10/2008, 926 2530-02 DS 02
187
6.7.7 Flip-flop
6.7.7.1 FF-SR
Description
The safety relay supports the reset-dominant function "FF-SR".
"Reset-dominant" means that the result of logic operation (RLO) cannot be set to "1" when
the reset input R is "1".
The function has:
● 2 inputs: Input for setting S, input for resetting R
● A function output Q for the RLO
The RLO is formed according to the following truth table:
Input for setting S Input for resetting R RLO
0 0 --
0 1 0
1 0 1
1 1 0
0 = low level
1 = high level
-- No change of the output status
RLO = 1, when the input for setting S = "1" and the input for resetting R = "0".
RLO = 0, when the input for resetting R = "1".
Parameters
Parameter name Description/parameter value
Name You can enter a name for the element here.
Element number Consecutive number which is automatically assigned. You can change
the number.
Element activated When this parameter is active, the function is processed in the safety
logic.
When this parameter is deactivated, the set substitute value is made
available at the output Q.
General
Function output substitute
value
"0" or "1" can be assigned to the substitute value when the element is
deactivated.
Substitute value "0" means output Q = 0
substitute value "1" means output Q = 1