Is there a command for a Ring Counter in ControlLogix?

Hi, I need to place a ring counter in my program. I have been looking under help and can't seem to find any info. on Ring Counters.

Thanks,
Amy

Can you give a little more definition of a ring counter? Type, speed, etc

I'm sure you remember me from before, I'm the one who is bringing in and sending info. from a MicroLoad.net. I figured out how to get the data. Now I need to get the data everytime i send or ask for a response. for example, i ask the MicroLoad.net device to send me the current flow rate then i will recieve a respose from the Microload.net device and I need to get that info. before i get the next question/answer. Does this make any since? Maybe i didn't describe it well.

So you are wanting to sequence through a set of request?

I forgot to tell you that I have Serial-In and Serial-out.

This is what I think is wanted:
1. Ask for Data 1
2. When Data 1 recv'd, ask for Data2
3. When Data 2 recv'd ask for Data 3

Is that correct?


Don't understand the reference to a ring counter.

Yes

Have you played any with indexed addressing yet?

Example - MyArray[MyIndex]

No. I do have the Arrays part but, I don't know what anything about indexing yet.

A ring counter is typically used to shift a state sequentially through all the bit positions of a word on every input. Example: 00000001, 00000010, 00000100, etc. You would do this if you had parallel outputs or commands that you wanted to sequentially enable with the same input. You can create something like this in Logix5000 by using the sequencer instructions SQI, SQO, and SQL. The online help file has documentation on these instructions.

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I think I understand what you are saying, but what is that indexed thing that TWControls was talking about in post #8, is that like what you (Money4nothing) are talking about? I'm sorry, I'm a little lost. So, I don't need a counter to do this task, just a sequencer instruction? I just printed off the help instructions for the sequencer, i will read these now...thank you

An array tag in control logix has an index which tells you the position of an element in the array. Example: MyTag[2,4], in which MyTag is a 2-dimensional array tag, and MyTag[2,4] would be the 3rd element in one dimension and the 5th element in the other. The index ([2,4]), or posistion, can be a variable, or another tag, which can be changed in a sequenced if you wish. You can write logic wich will change the index of your array tag reference in an instruction, to operate on a different element of the array tag whenever you change its index. The sequencer instructions make this much easier to do in some cases.

Edit: A further example of sequencing the index of an array tag:
You can make two counters, in which the .ACC value of the counters are the indexes of an array tag. Example: MyTag[Counter1.ACC,Counter2.ACC]. As your counters increment, whatever instructions that operate on MyTag will operate on a different element of MyTag each time.

Another edit: If you want to be real specialized, you can create an array of custom data types for the acutal operations that you want to perform, then sequence through them. For example, if you had to identify a different communication path each time, and the communication path consisted of a string and some numbers, you could have an custom data type that represented the communication path, then make an array of these that represent all of your different possible paths that you want to use.


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Are you saying that i could use counters with a sequencer? I'm sorry i'm new and I get lost a lot. If so do you have an example of this or know somewhere i could read about it?

No, you can use counters and arrays LIKE a sequencers if you have a simple application. A sequencer is better for more complex applications.

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Wow, this is confusing. What i just read about the Sequencer...do i have to use one for every step (like what was in post #6). So would a counter in my case be a better solution? If you don't know...I have 7 devices Smith Meter/MicroLoad.net, that I will be asking for info.(like Flow) etc. Then I will be contolling a VFD(variable freq. drive) that control a pump to increase or decrease the flow. In my case which do you feel would be better?

Thanks for your help. Amy