Time Relay - Siemens Simatic RTU303xC Series Operating Instructions Manual

5.10.4

Time relay

Function
The block has the function of a time relay. Application example: Staircase light switch
Tr
Q
T
a
T
T
!
T
!L
Figure 5-13
With the input signal "Trigger" (0 → 1) block processing is started edge-triggered and the
output of the block is set to 1. If the trigger changes 1 → 0 (for example due to releasing a
button), the "Off delay" begins to run.
After the "Off delay" has elapsed, the output is reset.
With the signal "Reset" the output can be reset to 0 before the "Off delay" has elapsed.
As an option before the Off delay elapses a warning signal can be output via the
"Prewarning" parameter. This indicates the turning off of the output by resetting the output
from 1 to 0 for the duration of the "Interruption".
The prewarning time is calculated from "Off delay" minus "Prewarning" (T - T
The optional output "Warning" is set to 1 at the time of the "Prewarning". The "Interruption"
has no influence on the "Warning" output.
Parameters
Parameters
Input parameters
En
RTU303xC
Operating Instructions, 06/2019, C79000-G8976-C382-06
Trigger
Output
Current time
Off delay
Prewarning
Interruption
Operating diagram
Tag type / range of
values
5.10 Switch and relay blocks
Description
Enable parameter, see section Often used parame-
ters (Page 252).
Program blocks
)
!
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