user definded data type in plc??

Hi, I still a little new to PLC's so please bear with me. My boss told me that I will have a Smith Meter MicroLoad.net communications and it will be RS-485. He told me to find a card for a ControlLogixs controller. Also, he told me I need to find out how to address them (he said maybe come up with a user defined data type in the PLC). I don't know what a user defined data type is.



This is probably a very simple task, but I have no idea what he is talking about. I have searched on the AB website (which, I can never seem to find what I'm looking for, probaly becasuse I don't know what to look for ) and I googled a lot. I have stumbled for a few days; maybe someone could point me in the right direction.

As I have found before, I guessing you will need some more info. to help. Just ask and I'll find out.


Thank you,

Snide

In your controller organizer (left pane) go to Data Files, User-Defined and right click and select New

From there give it a name, enter the tags you wish to have in it and the data type just like you would when creating tags.

Then go to you tag browser and create a new tag but instead of putting a normal data type (example DINT) enter the name of your user defined tag

Does this help? I wrote a document on doing this that I might be able to dig up if you think it would help. But probably after you create it you can play around with it and get the hang of it

In a user defined data type you create subtags such as in timers (Timer1.ACC, Timer1.DN). I use these tags for motors sometimes, where I have Motor1.Start, Motor1.Stop, Motor1.Aux, etc.

Some people use them in communications because you can make a UDT (User Defined Tag) and send bits, integers, reals, across the comm network but the tag only takes up one connection in the network.

Is there a paper on using UDT in communications so I could read more about this? thank you for your help.

I'll see if I can find the article. There are no other papers I am aware of.

Think of the user defined tags as a way of organizing data.

Normally you would have a tag called TimerTag type TIMER[10] in one section of memory and one call DINTTag type DINT[10] in another section of memory. By using a user defined tag you can mix TIMERS, DINT and almost any other data type and it will be in one block of memory.

I like to think of them as folders in windows explorer. You have the main folder, then you can have many folders underneath of this to keep your data organized.

If you get doing large Controllogix projects, you will almost have to use user defined tags to keep your sanity since it does not have the structure of RsLogix 500

Thank you,
I just starting my first project with a ControlLogixs. I'm sure I don't know a lot. oh, do you know what card does rs-485 for controllogix?

Amy

The idea behind a UDT (User-defined Data Type) is that a programmer can create a new class of tag which can completely capture all the control and status information associated with a particular piece of plant equipment. For example you could create a UDT called "reactor" which could be made of (amongst other things) "level", "fill_valve", "mix_speed". For every reactor you have on site you could create a new tag of this type; create one called "reactor_1" and you'd automatically create "reactor_1.level", "reactor_1.fill_valve" etc. etc.


They can also be used to capture all the data needed to communicate between multiple controllers; for interlocking, end-of-shift reports etc.etc.

In order to find out how to address a particular device you're best off contacting the vendor directly ("Can you tell me how to address one of your retro-encabulators from a CompactLogix, please.")although someone else on PLCS.net may have done this already.

It's very unlikely that you'll need to create a UDT for this job but, if you like the sound of the concept, you can try it. If you're very new to PLC's I'd advise against it; if you've done object-oriented programming in a previous job you'll love it!

Actually the serial port on the front of the processor can be configured for DH-485. Will that port be available or do you need it for programming?

NOP,
I'm not sure about your question

,("Can you tell me how to address one of your retro-encabulators from a CompactLogix, please.")

Click to expand...

I'm thinking I will have to call a vendor to find out what you are asking.

TWControls,
I'm not sure but, My boss said RS-485 is that the same as data highway? he told me i would need a card for this...Maybe I'm totally off. My boss hasn't told me much about the job yet.

thank you for helping me,
Amy

Perhaps THIS link will help. Also, are you looking for RS-485 which is a physical port type or DH-485 which is a protocol. I thought you were saying DH-485.

The module your boss may be refering to is the 1756-DHRIO. It does Data Highway Plus(DH+) which is not the same as DH-485.

I think the Serial Communications tab is what you are looking for

thank you i will check this out.

User-defined data types are of secondary importance to this discussion. What you first need to figure out is how this micrometer.net device communicates, and what module or technology in the ControlLogix is compatible with that method.

Google brings us directly to FMC's product pages for this device:

MicroLoad.net

Including the communications manual, all 166 pages of it. I am so far pretty impressed with how much backup information they provide in this reference manual; the introduction to serial communications refers to Samuel Morse !

The bad news is that this module uses a proprietary ASCII-based command language, instead of an industry-standard protocol like Modbus.

The good news is that the command set looks very straightforward, and the tools for using ASCII are readily available in the ControlLogix and in add-on cards.

Get that user manual, start reading, and start asking your boss what functions the MicroLoad and the ControlLogix are going to have to exchange.

The hardware involved in this could be as cheap as a $150 RS2323/485 converter, or as expensive as a $2500 TCP/IP raw socket communication module. It all depends on how fast and how far you need to go.

TWControls said:

Actually the serial port on the front of the processor can be configured for DH-485. Will that port be available or do you need it for programming?

Click to expand...

The port on the ControlLogix processor is RS-232 only. You will need an external converter to convert to RS-485

UDTs, how to

For more info on how to create UDTs, check Logix5000 Controllers Common Procedures, Chapter 3 - Organize Tags. There is about 6 pages of basic info and it's pretty well organized. You can find it under Help, Online Books in RSLogix5000.

If you are just getting started in ControlLogix the first three books under "Online Books" are very useful:

Logix5000 Quick Reference
Logix5000 Controllers Common Procedures
Logix5000 Controllers General Instructions

Good luck,

Vic said:

TWControls said:

The port on the ControlLogix processor is RS-232 only. You will need an external converter to convert to RS-485

Click to expand...

Then why is DH-485 an option? Not arguing your point since I have never used it. I just don't understand