Hello, please help.

stonez

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• Jul 17, 2013

• #1

I recently got a small homework assignment to make a program under step7 so my first 8 outputs on 313c would blink consecutively.

ex: q0.0 for blink once, then stop, afterwards q0.1 blink once then stop, then q0.2 and so on until q0.7, and start from the beginning.

I have managed with Pulse timers to blink them from q0.0 until q0.7 (used 7 timers, and is working great), but I dont know how to do it in a loop.

Please help thank you.

 

James Mcquade

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• Jul 17, 2013

• #2

please post your work so we can offer suggestions.
zip the file first.
regards,
james

 

stonez

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• Jul 17, 2013

• #3

Here is the program. I tried two methods. They both do the same, and for both I have the same problem. I don't know how to do the loop.

PS: I have spitted the 1,084 mb zip file in 4 pieces because of forum rules, and renamed (though correct filename, needed to be renamed like this) the led.z01, led.z02, led.z03 files to led_z01.zip .. led_z03.zip etc., so i could upload them.

Best regards,
Attila

 

Lancie1

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• Jul 17, 2013

• #4

Could you "print" your S7 program to a PDF file (file-print), so that those of us without the software could maybe help you with this program?

Another way is to make a snapshot or screen print of parts of the program, and post as JPG picture files.

 

Last edited: Jul 17, 2013

stonez

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• Jul 17, 2013

• #5

momentarily I can't do this because I don't have the software installed here at home. I will do this in 10 hours when I get to work.

 

L D[AR2P#0.0]

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• Jul 17, 2013

• #6

To make the project suitable for posting, create a library, insert an S7 program into the library and then copy your blocks to the library. Archive the library and then post as an attachment.

 

stonez

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• Jul 17, 2013

• #7

L D[AR2 said:

To make the project suitable for posting, create a library, insert an S7 program into the library and then copy your blocks to the library. Archive the library and then post as an attachment.

Click to expand...

I don't know what you mean. I have zipped the whole program there. It is possible to unzip it after you change the underscore "_" to a dot on the three respective files, so the extension of the files get back to z03. (ex: led.z03)

Ps: I have done this on request by James. (I will also make printscreens, tomorrow morning)

Thank you in advance.

 

stonez

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• Jul 18, 2013

• #8

Here are the print screens of the program.

Please help. Thank you in advance.

 

ojz0r

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• Jul 18, 2013

• #9

I think you should look into making a shift register. That will make your code more compact.

 

stonez

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• Jul 18, 2013

• #10

can you give me an example ?

 

Lancie1

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• Jul 18, 2013

• #11

Stonez,
Here is an example using a shift register. You probably need to add an additional network to reset the shift register to the starting position (to make it recycle).

 

Last edited: Jul 18, 2013

uptown47

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• Jul 18, 2013

• #12

It is possible to write a value (i.e a number) to QB0 (Output Byte 0).

The binary values for each bit are:
0000 0001 = 1
0000 0010 = 2
0000 0100 = 4
0000 1000 = 8
0001 0000 = 16
0010 0000 = 32
0100 0000 = 64
1000 0000 = 128

If I was to use a Move command and 'move' 64 into QB0 then this would bring on Q0.6.

If I 'moved' a 2 into QB0 this would bring on Q0.1

etc etc ...

Just another way to do the same thing without having to have a lot of 'normally closed' in your rungs.

The ideal way would be a shift register but I think this may be a bit of a steep learning curve at this juncture.

Experiment with the suggestions in this thread though and I think you'll learn a lot. ;-)

 

Jeebs

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• Jul 19, 2013

• #13

For a 1 sec pulse, do not use timers.
The S7 PLC has a Clock memory. Use F1 to see what it is, use it accordingly.

 

uptown47

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• Jul 19, 2013

• #14

Or you could use the System 1 sec pulse (as Jeebs said) to increment a counter and then use comparators to check the value of the count and bring on the appropriate output (and then a further comparator to reset the counter when it reaches the last output value).

;-)

 

Lancie1

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• Jul 19, 2013

• #15

The S7 PLC has a Clock memory.

Click to expand...

All PLCs have a microprocessor. All microprocessors have an internal clock that times the execution of the machine language. Some CPU clocks are more user-accessible than others. Timers are always accessible.