Hello.

karthikk

Hi there, 

I would like to have a 30 mins pulse where i can count up a counter value. When there is one complete cycle of pulse, i need to increment the counter value to 1 (for every complete pulse i will need to increment the counter value by 1 up to 24 (representing hour)

My suggestion would be to have an inner and outer counter. The inner counter tracks smaller increments and the outer one is for the hour count.

The system memory bits can give a minute pulse which can go to the inner counter. So how many seconds in an hour..?

BR

#dP

So how many seconds in an hour..?

OT. This is not trivial question.  

hi #dP, 

Possible to provide some screenshots on how to the inner & outer counter value?

Sorry for the trouble.

Hello.

karthikk

hi #dP, 

Possible to provide some screenshots on how to the inner & outer counter value?

Sorry for the trouble.

How about some team-work?I will give you some instructions.

1. Create a new project and activate the system memory and clock memory in the hardware configuration. "Clock_1Hz" will be a tag created by default.
   
   
2. Add tags and code to count every pulse given by "Clock_1Hz".
   
   
3. Use  -|P|-   to ensure that only the edge of "Clock_1Hz" is counted.
   
   
4. .. more to follow if you can show a project for these steps.
   

BR

Hi, 

Attached is the counter value increment for every 1Hz pulse.

 Hello.

karthikk

Hi, 

Attached is the counter value increment for every 1Hz pulse.

It looks good.

I must confess, my preference is to not use the IEC_COUNTER. Please confirm that the Q output does come on only after going beyond the setpoint of 5.

In other words: it is important to know if the Q output comes on when the count >=5 and above or only >5 (>=6).

The next steps:
- Link a  --( ) after the Q output of the counter; place a M-bit tag there.

- Use the same tag and place that to the R input of the counter. Now the counter will count to 5 and reset itself. Simulate that to confirm.

- The same tag can now feed into a second counter. Unlike the first counter you do not need to use the -|P|-.

- The first counter (from your picture) is the inner counter. The newly created counter is the outer counter. Set the inner counter target to count seconds of an hour. The outer counter then count the full hours.

- Evaluate the result and customize to actual requirements.

BR

Hi!

how about generating your 30min impulse yourself?

 Hello.

NiM_0021

Hi!

how about generating your 30min impulse yourself?

No problem with the idea. 

Keep in mind that the question is actually of counting hours not about counting 30min. The original idea was to generate a pulse of 30min on and 30min off.

Do not use the design you showed on the S7-1200 and S7-1500. There is a design flaw / feature that is going to work against you. The proposal based on your design is:

The emphasis on the memory bit "mem".

Note also the built-in flaw with the design. Every reset of the timer you will loose the time associated with 1 - 2 scan cycles. This inaccuracy is seldom an issue.

Piotr.M's suggestion is more accurate and worth to investigate.

BR