Ethernet communication with Drive in AB

Hi there
Well Iam new to AB system.
The controller is 1768-L43 (Compact Logix) and the drive is Power Flex40. The controller will communicate with drives through ethernet. The ethernet card being used is 1768-ENBT.

How to start programming this. I need to send the Speed to drive, read the speed feedback and read drive current. Is there any special inbuilt function in AB for ethernet communication?

Thanks for the time,

There really isn't a built-in function that you need to use; you need to add the drives to the I/O tree in Logix 5000. Logix will then create the tags for you. BTW, what type of drives are you talking about? The above work for PowerFlex drives and probably other AB drives too.

Sorry, you did mention PF40. Just add the drive to your I/O tree and you should have no problems.

Thanks Jkerekes
Are you asking me to add the drives in I/O tree shown in the picture?
Also if I right click on 1769 bus then it does not comes up with drives option over there only analog,communications,digital,other,specialty !!

Anything wrong??

Oh i got it
I have to right click on Ethernet card and there is an option to add drives !!
Will come up with further inquiry if any

I was just about to tell you that yes, you need to add it to the Ethernet network (card). Glad you got it working.

Ok one more question
Do i need to send the speed at the location shown in the picture?

Also
Can I create new folder to put my tags in it.
Creating all the tags inside "Program Tags" is bit confusing.

How can I create new folder to segregate the tags for different purpose?? Can I do it.
Software is RSLogix 5000

Yes, with Freqcommand you send the speed to the drive. It's an integer value which you have to scale first before sen to the drive. I don't know the count numbers to scale for the PF40, you have to read it in the Feedback. When you found it, you scale the 0 to max speed (in Hz or RPM) to the counts of the Freqcommand. For example 0-60 Hz scaled to 0-14787 counts. This can be make with the SCL function in ladder or FBD in RSLogix 5000.

To read the feedback also have to be scaled for correct reading, from counts to eng units. The Output Current value you have to divide by 10 (at least in PowerFlex 700, not sure is the same in PF40), but is easy to check reading the display and compare the value in CompactLogix.

Other thing you have to do is configure the parameters of the Drive to take the speed reference from DPI port (the Ethernet Adapter) and not from an analog input.

Respect to create a tags folders, Logix5000 works with controller scoped tags and program scoped tags, not with folders like and HMI like RSView32. Controller tags are global tags (you can use in any program, routine) and program tags are local tags only for that program. When you add drives and I/O modules to the tree, tags are created automatically like controller tags, you can't change it.

The thing you can do is create program tags and point that tags to the controller tags. For example, you can create a INT tag called "Speed_Reference", and then in ladder routine you make a MOV with Speed_Reference to FreqCommand.

When you read program tags from an HMI like FTView, yo have to search them in the related program folder in the tag browser, not in the controller tags.

Hope this help you.

Many thanks rleon
Will send the speed to FrequencyCommand tag of the drive. Regarding scaling will do as you said.

Its sad that tag folder cant be generated !! One thing is to create add-on instruction to have a different tag folder !! But then using add-on instruction will not solve the problem all the time !!

One more thing. Say i have to first divide and then use the result to multiply to get my value. So I have to use DIV and MUL blocks. Problem is Iam supposed to create a tag for destination of DIV block which will be then Source A of MUL block. This destination tag has to be under Program Tags.

Is there any local memory or some thing like that, which can be used for such intermediate purpose?? without needing to creating tag??
Any kind of accumulator concept as in Siemens ??

Well I found out that you can group the tags related to a particular process under one name. This can be done under User Defined Data Types

I also wish there were simple folders that you could create to put tags into in the Logix. With a UDT you still have to make use of the tag definition and it will be located with all your other tags in the program or controller tags. You also have to use existing tags to make the UDT. Dont get me wrong, I love UDT's. You can use it to group certain tags, but dont limit yourself. Defining your own tag structure can be much more powerful than that. Take the tag structure for the drive shown in a post above. You can have 50 drives and they can all use the same tag structure for easy addressing. By the way, I notice that you grouped your data types. I dont know if you did that on purpose or not, but that is the most memory efficient method to make UDT's.