Block transfer control files

Presently I am using A.B. 6200 software. I am programming a plc5 processor. I have successfully programmed an analog input and output card. By using the example in the manual I entered control file as n10;0 and data file as n10;5 in my BTW. Or the numbers may be vice/verse. Nonetheless I have some questions about control files and data files. Lets say I make the cntrl file N10;6 and data file n10;22. Can i do this? If so what do words n10:0-5 function as.
Actually if someone could just chat a bit about these files in a BTW or BTW in laymans terms it would help me tremendously. Be preparred I think i will be posting alot of questions!!! and hopefully some answers too. Thanx

Here is clip for the PLC-5 Reference Manual.



It contains a whole chapter on Block-Transfer Instructions.
Here is a like to the manual on the Allen Bradley Website.

PLC-5 Instruction Set Reference Manual

Kim

the Block Transfer "mailman" lecture

short on time but - the 5 integer words of the CONTROL BLOCK are used to “control” the operation of the Block Transfer - quick analogy: the Block Transfer is a “mailman” - if it’s a Block Transfer WRITE then the mailman is carrying mail FROM the processor TO another device (like your analog card) - if it’s a Block Transfer READ then the mailman is carrying mail TO the processor FROM the other device (example: your analog card) - in simplest terms: the Block Transfer WRITE “mailman” does NOT write the message - he just carries it FROM the processor - the Block Transfer READ “mailman” does NOT read the message - he just carries it TO the processor - specifically, the terms READ and WRITE serve only to tell us in which direction the data is being moved (data FROM the processor = WRITE; data TO the processor = READ) -

next point - using the “mailman” analogy, consider that the 5 integer words of the control block are the “address” on the outside of the envelope - example: it takes 5 pieces of information to convey MY personal mailing address - my NAME - my STREET - my CITY - my STATE - and my ZIP CODE - (of course this is an oversimplification - but it works well for beginners)

next point - using the “mailman” analogy, consider that the integer words of the data file are the “message” inside the envelope - specifically, the actual information that the message conveys - example: scaling values, analog signal values, etc. - how many words are in the data file? - the Block Transfer’s LENGTH entry tells the mailman how many words of data to transfer -

that should get you going - now here’s a VERY instructive experiment to hammer it all home - and you DON'T need a processor to try this - it will work OFFLINE too -

start a brand new temporary program - program a quick BTW rung using N7:0 for the control block - use N7:5 for the data file - set the rack to “000” (“00” is the same thing) - set the group for “4” - set the module for “0” - set the length for 37 - set continuous for “No” - nail down the rung and then proofread the entries carefully - now notice that the first word of the control block is N7:0 - next go to the data table location for that word - notice that it currently contains the value “8” - manually change N7:0 to contain the value “4095” - now take another look at your Block Transfer entries - WHOA! - what the heck happened here? - now change N7:0 back to the value “8” - how about THAT sports fans? -

major concept: once the control blocks are set up for your block transfers, STAY-THE-HECK-AWAY-FROM-THOSE-LOCATIONS - clumsy changes to those values will blow your Block Transfers completely out of the water - keep this in mind as you reference the first word “bit patterns” in Kim’s post above -

one more thought: suppose that you have a TON timer rung in your program (example: for T4:0) - what would happen if you were to go to the timer’s location in the T4 data file, and change the value stored in the Preset? - try it if you don’t already know the answer - give away: changing the value in the Preset location on the data table file will automatically change the Preset value shown in the timer rung - think about it this way: T4:0 on the data table is the “CONTROL BLOCK” for the timer! - most people never look at it that way, but it’s a perfectly valid concept - point: a timer needs a “control block” in the processor’s memory - a Block Transfer needs a “control block” in the processor’s memory -

finally, you might want to experiment with using the “BT” type files for your Block Transfer control blocks - just keep in mind that not all PLC-5 processors support the BT file types - so it’s best to understand the integer types, and then consider the BT types as a “simplified” way of setting things up - quick analogy: learn to drive “clutch pedal and stick shift” and later on “automatic transmissions” will be a piece of cake -

First i would like to thank Ron and Kim for there extremely valuable info and analogy.Secondly I would like to state that i made my post before viewing several other posts...at which point i said "ugh oh" these are some pretty serious folks in here so i kinda thought i might get a verbal lashing for asking a "stupid question." But nonetheless my question was taken seriously and your answers more-so.
A little bit about myself. Ive been a maintenance electrician for about 9 years. I have done some simple programming. Presently where I work electricians do not work with any programming, that is left to the electronic techs and engeneering. Being somewhat computer literate and just plain curious about plcs I asked my boss if I could build a plc "play station" if you will. He encouraged me to do just that. So I started poking through old dusty boxes of i/o cards that were labeled "good,bad or unknown" and grabbed everything. I then aquired what at one time i believe was considered a "laptop" computer. It says its a VIIIb/w. Its about the size of a masonry brick. It weighs about the same as a masonry brick, and has a low contrast black and white monitor about 6inches by 8 inches. Its running on windows 3.1. Well i just started hitting every file thats was on that fine computer and sure enough found ipds or a.b. 6200. no help files though, bummer. In about two weeks I've managed to hook up a thumbwheel which is controlling a dozen sequencers which put on pretty light shows on my output cards, to spark other electricians interest, which it has. I also have analog i/o hooked to a pot and a digital display. I also have a very high speed counter wired to an encoder that is indeed chucked up to a dewalt 18 volt cordless. This stuff is COOL. As much as i would like to get a newer computer and rs logix I figure I might as well learn it the hard way, which really isn't that bad. Anyway I just wanted you all to know I am serious about learning. I will try to limit my questions about anything until I have exhausted all options and let you deal with more complex issues. I sincerely appreciate your BTW help Thanx again.

bulletin blues

I can almost hear your enthusiasm from your typing...

Yes this type of equipment and hands on training does open up a whole new world to you. I had built an Allen Bradley PLC5 "simulator" about 8 years ago for our maintenance staff. I also had to use salvaged parts and pieces (most companies don't seem to maintain much cash reserve in their training budgets). This was originally a PLC5/15, chassis, power supply and a few I/O cards. It is now also used to troubleshoot and repair I/O cards, load Basic Module programs, load programs for processor replacements when a processor fails in the plant and to test program changes before editing Online Processors. We carry only one spare PLC5/40 (this is the most advance processor revision we have in our system at this time) and are able to load any of our PLC programs to temporally operate a PLC5/15, PLC5/30 or PLC5/40 system should a processor failure occur. Of course we have other sub systems with Micrologix and SLC500 systems and have replacements for those also.

We found that we had to limit the number of minds and hands we set loose to programming and editing of the PLC programs operating equipment. So I have been allowed to train one person on each shift (this really helps to limit those 3 AM calls to come in and troubleshoot problems). The processors are now password protected to only allow the select individuals access to edit programs. But the training I can continue with the rest of the staff will eventually allow any of the maintenance personal to "view only" any PLC in the system for equipment and operations troubleshooting purposes.

This link is to a post about some of the fun stuff you can do with PLCs, besides controlling plant equipment. This is my personal "PlayStation".

FireWorks Display

If it is at all possible don't limit yourself to Allen Bradley only. There are other very good PLCs out there. Even though I do not get to work with these on a daily basis, I would have to say that working with other systems has broadened my knowledge base and skill level considerably.

Any way keep at it, keep asking questions and review the posts in the archives (there is quite a wealth of information in there).

Best Regards Danocane

Sorry About the guest thing

I guess I wasn't logged in on the post above. I am logged in now though.

Thanx Dan

If you dont have the manuals for the plc5 or 6200 they can be obtained at:
http://www.ab.com/manuals/swrsi/

No one seemed to mention the use of the BT data file type. If the processor that you are using supports the use of BT (Block Transfer) data files I would highly recommend using that for the control of the block transfers. The BT data type formats the control structure for block transfers into a nice organized formatt. You will have the enable bit, done bit, enabled waiting bit, start bit, and error bit. Plus it will be easier to keep the control of the block transfers seperate from the data of the block transfer and not have to worry about the control getting hosed up from writing to the wrong location.

Well thanx doc. I think I'll take you up on that suggestion. Actually Ron B. hinted at using the B.T. files but recommended I get to know how to use the integer files first, which seeing as though I'm just starting out is probably a good idea. Thanx to Kim's link I now have some info on where to start. I am using a 5/30 processor which I believe can use the B.T. file. I can definitly see the benifits of this because I'm starting to rack up alot of integer files and it is getting a bit confuzing. Wow advice from a doctor and it didnt cost me 90 bucks!!!

I should probably make another post for this, but... does anyone have any experience with Allen Bradley online training? Specifically R.S. Logix. There site says its about 700 dollars which I might be willing to spend. Also I need a copy of R.S. logix on my computer. If the technical dept. at work made me a copy of this to use at home would Rockwell frown on this and make me purchase the software from them? I have taken a one week course in basic R.S. logix programming, would the online course extend beyond this. I should contact Allen Bradley but I'm just testing the waters a bit.