Switch And Relay Blocks; Latching Relays - Siemens Simatic RTU303xC Series Operating Instructions Manual

5.10

Switch and relay blocks

5.10.1

Latching relays

Function
The input parameters "Set" and "Reset" set the output to 1 or 0:
● Set
A positive edge (0 → 1) sets the output to 1.
● Reset
A positive edge (0 → 1) sets the output to 0.
The parameters "Set" and "Reset" both have a latching function.
When "Set" and "Reset" have the same value (both = 0 or both = 1) the switching of the
output is controlled by the function parameter "RS/SR priority":
● SR: The output is set to 1.
● RS: The output is set to 0.
Table 5- 4
RS/SR priori-
RS / SR
RS / SR
RS / SR
Diagrams
The two following diagrams in which the RS/SR priority is programmed differently are
examples showing the effect on the output.
The blue arrows indicate value changes of the output Q that are caused by the programming
of the RS/SR priority.
RTU303xC
Operating Instructions, 06/2019, C79000-G8976-C382-06
Status table:
Value of
ty "Reset"
0
1
0
RS 1
SR 1
Value of Value of the
"Set" output
0 -
0 0
1 1
1 0
1 1
Program blocks
5.10 Switch and relay blocks
Remark
The value of the output remains un-
changed.
Value of the output regardless of
RS/SR priority
Value of the output regardless of
RS/SR priority
315