S7-300 help needed

Geofra,

from what I see on the doc file, the shift right has been executed. The only question left is: what's in the other networks? Because you don't show us all of the program, we can't give you an answer about what you problem could be. It could well be the other networks have instructions which make this program work incorrectly.

Remember: giving only partial data can't result in a complete answer. Only complete data may result in a complete and correct answer.

Kind regards,
 
This shift right will execute as long as the input is true, is this what you mean to happen ? - I think you will get a random number of shifts depending on how long the digital input is on.
 
jvdcande
I have tried the above code (only two networks) in an emty OB and it doesn't work.It shifts only once and if I make the EN input high again nothing happens. If you see the attached file the strange thing is that when I monitor the PLC, MW100 at the input of SHR block has the value 8 and MW100 at the output has the value of 4 after the first execution. If I do this on an S7-200 PLC as soon as the block is executed the value at the input will be updated with the new one and become 4 so if I execute again it will become 2 and so on.
 
Geofra,
as Simon stated, the SHR block are cylic
executed while the Input is true.
You should use a oneshot in this rung.
To see how it works I've attached a PDF

HTH
Rolf
 
Rolf ,

I have tried what you and Simon have suggested but with out success.
It's very strange as this is supposed to be a simple operation.
What confuses me more is the values of MW100 at the various points.
Since I enter the value W#16#1000 which is supposed to be a HEX and not a binary number why do I have W#16#0008 at the input of the SHR-W. One more thing that confuses me is that I don't know what the current value of MW100 is as I see three different values when monitoring.(You have to see the attached file in my first post to understand)
 
I'll try again...

I've been away from Siemens stuff for a long time, so I can't be of much help. That said, here's what I make of GEOFRA's logic:

Network 2:
When input 5.0 is ON, the binary value in MW100, which is 00001000 (decimal 8) is shifted one place to the right. The result, 00000100 (decimal 4) is placed in MW100.

Network 3:
When input 5.0 is ON, the binary value 00001000 (decimal 8) is moved to MW100.

Since both networks are triggered by input 5.0, MW100 continues to be overwritten each scan, as I suggested in my erlier respond in the OTHER THREAD GEOFRA started.

šŸ»

-Eric
 
Eric ,

Your comment would be correct id I5.0 was used in both networks.
In the first network CIP421 is I5.0 and in the second network CIP422 is I5.1. Both inputs are triggered manualy be me for testing.
So i trigger CIP422 first to load the value W#16#1000 which is supposed to be a HEX so it shouldn't be interpreted as 8 and then I turn CIP421 (I5.0) on to execute the shift Right.
 
You need to have the edge detection logic to see the shift taking place. You also need to monitor MW100 in a VAT table to observe what is happening to MW100 as the values on the screen are only valid whilst the rung is executing. If the rung is not executing, the values are only valid for when the rung last executed.
 
S7-300

Rolf,

After paying more attention to your file I realized what my fault was. As my experience is with S7-200 where the positive transition is not addressible, when I used the positive transition coil in S7-300 I had the idea that I had to turn it on too , so i inserted one more network before the shift left which would turn the transition coil on.
Thank you all for your help.
 

Similar Topics

I have a siemens 317-2 and an old GOT1000 (GT1675M - V) I am trying to get the darn things communication and having no luck. I have followed the...
Replies
12
Views
2,066
Does anybody here have a manual for the DC-300. I have the tiny manual that discusses some of the fault codes and common parameters, but I'm...
Replies
0
Views
1,956
Hi guys , I need some help on a project am doing. I have a lot of experience with s7-200 but is my first project with S7-300. I understand only...
Replies
2
Views
3,380
Hello, I have a die punch machine with servo motor for material feeding. I'm using Kinetix 5300 to control the feeding system. Every recipe have...
Replies
0
Views
450
Hi to all, Our company does not usually use Siemens PLCs, but have a press with one in it. We are trying to change the IP address in our Simatic...
Replies
2
Views
1,040
Back
Top Bottom