Set Time in S7

snydl0ga · Apr 11, 2005

Anyone have simple code for setting the DateTime (SFC0) from data in DataBlocks?

S7 318-2 CPU

I can read the clock into data blocks but now I have to synchronize the D/T with our PCs so I need to set the D/T in the PLC.

Lance

snydl0ga · Apr 13, 2005

No Info on Syncing time from a PC running VB? Or how to combine the yrs, days, month.....etc into a DT variable to send to Set_Clk ?

Ken M · Apr 13, 2005

Or how to combine the yrs, days, month.....etc into a DT variable to send to Set_Clk

You're almost there. The single DATE_AND_TIME data type extends over several bytes. These hold the year, month, date, hour, minute etc Check the STEP7 online help for the order of these bytes. Search for DATE_AND_TIME.

Thereafter, if you've already got the individual values stored somewhere in a datablock, you can just use the standard Load and Transfer instructions to populate the DATE_AND_TIME bytes with the values you need. Let's just do the year, month & date as an example. Assume you've got 3 INTEGERS in MW0, MW2 and MW4 and your DATE_AND_TIME is in DB1 starting at DBB0

Code:

L MB1	 // You only want the LSB of the word
ITB		 // convert it to BCD/Hex coding
T DB1.DBB0 // Store in the first byte of the DATE_AND_TIME
 
L MB3	 // You only want the LSB of the word
ITB		 // convert it to BCD/Hex coding
T DB1.DBB1 // Store in the 2nd byte of the DATE_AND_TIME
 
L MB5	 // You only want the LSB of the word
ITB		 // convert it to BCD/Hex coding
T DB1.DBB2 // Store in the 3rd byte of the DATE_AND_TIME
 
.....

etc etc

Once you've filled the DATE_AND_TIME, just call the SFC and tell it the address to get the data. Give the DB1 a name, and you can use the whole structure symbolically like "TimeStore".Now where TimeStore is DB1 and Now is the name of DATE_AND_TIME variable.

Good luck

Ken.

snydl0ga · Apr 13, 2005

Good info ! Got this thing going. Thanks a bunch.

Set Time in S7

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