PLC 5/30 and Output word value

I just joined this forum today.My questions will be fairly basic (rookie)and will refer to the AB PLC 5/30 series processors.I also work with the SLC 5/04 series so anything pertinent that relates to them is also of interest to me.Here is my question.
I am looking at the File00 Output Usage table.This question is for a 1336 Plus II VFD.I am using the Binary/Subelement Radix view.
O:050 is the control O/P word.Bits 0,1,and 3 show usage for Fault Clear,Stop and Start.It is not marked as a Word

O:051 is the Speed O/P word but none of the bits shows an X for usage (???).In the FW column (next to the bit 17 column)it shows a W.This tells me O:051 is being as a Word value.The connection is via the "blue hose" serial cable.How do you "tell" the PLC that you want to use the output as a word value as opposed to just individual bits.
We also have several places where the B3 bit files are designated as "WORD" values (B3:16 shows a W) as opposed to just using them as individual bits.I have searched the help files and it mentions them being used as word values but dosnt mention how to tag them this way.I guess I could ramble on and on but I think some of you pro's out there get the gist of my confusion.Thanks anybody out there who can help straighten me out.

JimL

No tagging involved.

The usage information is derived from the program.
If a bit has been addressed anywhere in the program (by XIC, OTE, etc.) it gets an 'X'.
Similarly, if a word has been addressed, (MOV, ADD, etc.) it gets a 'W'.
If a word has been referenced in a file instruction (FAL, COP, etc.) it gets an 'F'.

To find out where they've been used, do a cross-reference (XREF) - highlight a bit or word, right click & choose xref.

JimL,

The short answer is: it is all done with the way you write the ADDRESS. For example, for the PLC 5/30 that you mentioned, O:050 is the address for an Output Module in Rack 05, Word 0. Notice that each "Word" in the PLC has 17 bits. If I write "O:050" that tells the PLC that I am looking at the entire Word. If I write "O:050/1, that tells the PLC that I only want to look at 1 bit out of Word O:050. The address for Bit 1 would be O:050/1, Bit 17 would be O:050/17. Some commands and functions work with words or bits, and some only work with bits, and some only deal with whole words.

Now, you seem to be concerned with designating Words and Bits within Words as being "used" or not. This is not something you need to concern yourself with. Instead concentrate on knowing which bits are used for what purpose.

Remember you can look at whole words as one entity by changing your Radix from Binary (Bit view) to Decimal or Octal. In Decimal and Octal you are looking at the value of the entire Word, or all 17 bits. Sometimes this is appropriate if you want to copnsider a number or value of some entity. Usually if you want to know if something is On (1) or Off (0), that takes only one Bit, and you want to use Bit-level functions and commands.

As to "tagging" addresses as Bits or Words, you need to learn the PLC Address protocol first. This always tells if you are dealing with a Word or Bit. Then if you want to add a name or comment to help you keep them straight, that is what the "Edit Symbol" and Edit Description" functions are designed to do.

Lancie1,
As I am sure you are aware their are not 17 bits, only 16. Because of the octal numbering system used by AB for inputs and outputs,
bits 8 & 9 do not exist. This can be very confusing for someone new or old.

Mickey said,

As I am sure you are aware their are not 17 bits, only 16. Because of the octal numbering system used by AB for inputs and outputs, bits 8 & 9 do not exist. This can be very confusing for someone new or old.

Click to expand...

Mickey’s right, of course ... but let’s take it just one step further ... since jimlew2 admits that he’s “brand new” at this, let’s mention that the Allen-Bradley PLC-5 family uses octal addressing for the input and output bits ... but the SLC-5/04 that he also works with uses decimal addressing for the input and output bits ...

regardless, there are (as Mickey said) 16 bits in each word ...

Hey guys,thanks for the info.I kind of suspected that the way a file is used determines whether it is a word value,but I could never have it "confirmed" to me as you guys have done.Its just a small step but its helped me a lot in my overall insight into this process.
I have worked with PLC's awhile,but only as a troubleshootnng tool.I can do the routine stuff like forcing,finding the rung I want to see why something isnt turning on -ect.I can even do simple programming like adding inputs and outputs and using the bit logic for interlocks.When it comes to things like "bit shift arrays" COP,FLL and the more complicated stuff though,I am out of my league.As time permits on my shift I spend as much time as I can pulling up different PLC and SLC programs and watching the logic execute.The place I am working at now is somewhat disorganized(anybody ever been in that position <g>.)and our senior electrician who did most of the programming has moved on.
Again,thanks for the insight and I will digest this before my next (many to come)question.Gotta put 2 nintys and an offset in a one inch rigid pipe now so adios.

Greetings jimlew2,

As time permits on my shift I spend as much time as I can pulling up different PLC and SLC programs and watching the logic execute.

Click to expand...

this is a good way to learn ... but I'd like to suggest something else (better?) too ... IF (big if) you can get your hands on a "spare" PLC/SLC system, then try experimenting with some of the programming concepts which you don't understand ... just "playing around" with a simple program of just one or two rungs can often teach you a lot more than simply watching things on the screen turn off and on ... since the terms "playing-around" and "the-plant's-production-machinery" don't work too well together, a spare "trainer" PLC system is an ideal way to learn ...

good luck ... and welcome to the forum ...

Mickey, and Ron,

I should have said:
"the value of the entire Word, or up to Octal 17 in bit counts."