S7 Time of day event

I need to add to my program a pump, that automatically starts at 6.00 am and stops at 22.00 pm.
How can I use the integrated clock in a S7-300?
I will also add the possibility, so that the time can changed by typing it on a OP-Panel.

Can I make this timeevent, or do I have to use a extern clock?

Thomas

Thomas,

check the helpfiles for OB10 to OB17 - time-of-day interrupt. Also check the systemfunctions SFC28 to SFC30, with which you can set, cancel or activate the interrupt from within the program.

Kind regards,

Jean Pierre Vandecandelaere

Can you please explain it a bit more. I can get it to work.

Thomas

Hello!
To read the the time use "Read_CLK" SFC 1.
(output is struct of bytes, use BTI to get the parts if you do not use the IEC fc 8)

Use IEC blocks FC 8 "DT_TOD" to get the exact time

first:

CALL SFC 1
( RET_VAL :=#cur_RETVAL,
CDT :=#OUT_TIME_DATE);

CALL FC8
( IN :=#OUT_TIME_DATE
RET_VAL:=#OUT_TIME);l

L #OUT_TIME
T MD 10;

then you just have to compare the values and trigger your funtions, read the help files in Step 7 "program blocks"

Niclas,

the method you explain will work, but is less efficient than the method using time-of-day interrupts.

Thomas,

sorry, but the explanation I could give you would be the same as you can find in the help files from Step7 short of giving you the solution. I'm earning a living teaching and I won't throw away my earnings, so you have to show you have done something yourself before I should help you any further. Please put some effort in!

Kind regards,

Jean Pierre Vandecandelaere

I'll give you a head start. If you are using a TP170b and you want to read and set your clock in the PLC, your in luck. Hopefully, you have Protool to configure the TP. The attached program stores the current time in a DB and allows a NEW time to be set with a bit from a button. All you have to do is to write the compare block for your on / off time. I would strongly suggest using the TP170b and putting the ON /OFF time on a screen. If you can't figure it out, drop me an email, I have already written the compare blocks, but you can do it!

Date and time of S7 plc

Get simply the time and date of the plc by using SFC1, FC6 anf FC8

Once you get this data in a DB, you can compare it and do anything with is. You can even select the days, months, years... you want to work with.

Best use it by programming in SCL.

Bye

Walter