Astronomical Clock - Siemens Simatic RTU303xC Series Operating Instructions Manual

Parameters
ON1 .. ON3
OFF1 .. OFF3
Pulse
Output parameters
Output
5.6.10

Astronomical clock

Requirement
Requirement for a precise calculation is the time-of-day synchronization of the RTU.
Function
This function sets the output to 1 if the system time of the RTU is between the times of
sunrise and sunset.
The RTU calculates these times based on its current system time (including time zone and
daylight saving/standard time) and its geographical position. Make sure that the time zone
and daylight-saving/standard time changeover are set correctly in order to obtain correct
changeover times.
If you select "System location" for the "Position" parameter, the RTU uses the geographical
position configured on the "System" WBM page. With the setting "Manual" you can set
position values for the block. With the "Variable" setting, the coordinates at the two inputs
"Latitude" and "Longitude" are used as geographical position to determine the times.
With the "Deviation sunrise" and "Deviation sunset" parameters, the two switching points of
the output can be moved by up to 120 minutes to an earlier or later time.
Parameters
Parameters
Input parameters
En
Latitude
RTU303xC
Operating Instructions, 06/2019, C79000-G8976-C382-06
Range of values Description
[hh:mm] Input boxes for three turn on times
Input boxes for three turn off times
ON / OFF The enabled option only sets pulses at the output instead
of permanently ON.
Tag in which the value calculated by the block is output.
Digital output / bit
•
memory
Range of values
Analog memory bit config-
ured as a floating-point
number:
±3.402823e-38 ..
±3.402823e+38
5.6 Blocks for time functions
Description
Enable parameter, see section Often used parame-
ters (Page 252).
You only need to assign the input if you configure
the "Latitude" function parameter for the "Variable"
setting.
Analog bit memory of the floating-point number
type:
North = positive
•
South = negative
•
Program blocks
277