metwally mustafa

how to set a one year  timer in s7-300????

 Hello,

You can make your own timer, I always use the positive edge of 1 second clock memory bit to count seconds in a DINT variable then after it reaches 60 another DINT Variable representing minutes is incremented by one and so for the hours, then days and years.

You can use the variable you wish and compare it with the number of seconds, minutes, ...years as you wish

I use FB to implement this customized timer inside so that I can use it in any project I need

It worked with me very well, I hope this can help you

Dear Ayman Elotaify,

                              Thanks a lot for ur Information ..I need for some other doubts. If PLC is switched off in one OR two week for machine maintenance Purpose means . The Calculation time ill be changed ???

Regards,

Arasan..

Arasan

                              Thanks a lot for ur Information ..I need for some other doubts. If PLC is switched off in one OR two week for machine maintenance Purpose means . The Calculation time ill be changed ???

Regards,

Arasan..

                

Hello,

Another option is to use of system clock SFC1(READ_CLK), but as the time passes plc clock will behind the actual time with 5-7sec daily. Average mismatch of time will be around 40minute in your case.

You can power on/off plc for 1/2 week , no impact in logic until unless you remove mmc(as i think, there may be another reason also).

Regard's

Arasan

Dear Ayman Elotaify,

                              Thanks a lot for ur Information ..I need for some other doubts. If PLC is switched off in one OR two week for machine maintenance Purpose means . The Calculation time ill be changed ???

Regards,

Arasan..

                

 The calculation time will not change, as it reads the system clock and compares it to the time set in the hardware interrupt OB10. So if no one changes the internal PLC time (like making a time synchronization with another master like a PC and user changes it), Ayman Elotaify's solution is valid.

But the calculation will be invalid in case of using Ibrahim Fathy's solution, as the counter will stop when the PLC power is off.

metwally mustafa

how to set a one year  timer in s7-300????

 instead of using timer the Time of day interrupt will be good to use

if want to go with the year based timer then you can make a standard FB using clock pulses and addition blocks 

Hello,

It is the application that determines whether you need your timer to continue even the PLC is switched off or not

Sometimes you need to do maintenance after a year of work for some kind of device in this case (if you need to use PLC to calculate that) it shall not count when the PLC is off

Any way, It is wonderful to have all of these ways in one thread but it is the application that will make you decide which one to use

Hello,

               Thanks to everyone .. Going to take system clock And compare it too Hard ware Interrupt OB10 Means it fine to work .(AMAZINGAHMEND Said is valid Point ). Anyway Thanks a lot for giving Solution..

Regards,

Arasan..

Hi metwally mustafa

Your application will define which method you will use, do your quire high accurate time or not? for a long range of time you will find a time shift so you will require a time synchronization device as mentioned by amazingahmed.

So can you provide more data in order to help you