1771-IFE --- Need HELP understanding BTR and BTW!

[Ron Beaufort]

I'm not sure that I'm reading your "implied" comment correctly – so just ignore this if I've misunderstood ... if you mean that the significance of the five-word control block was merely "implied" – then I apologize for not making that point more clear "way-back-when" I originally wrote that old post ...

then again, here are some excerpts:

short on time but - the 5 integer words of the CONTROL BLOCK are used to “control” the operation of the Block Transfer ......

consider that the 5 integer words of the control block are the “address” on the outside of the envelope ......

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 ......

sometimes it's easy to misunderstand each other in this "typing" format – so let's don’t get hung up on the communications aspect ... anyway – if you're still having trouble tomorrow morning, maybe you can give me a call and I'll try to walk you through some of the details ... my guess is that you'll have it all worked out very soon ...

party on ...

 

[Ron Beaufort]

one more item before I head for home ...

I do have data (as in it is not zero) at N7:22, :23, :24 and :25. When I cross reference this I don't come up with those addresses being used anywhere in the program.

first of all, let's make sure that you're not confusing the "Find All" search feature with the "Cross Reference" feature ... many people do that ...

using the addresses from your example, the Cross Reference shown below DOES show the address N7:22 to be used – but only in a sneaky underhanded way ... when you're working with multiword "files" in the RSLogix packages, you have to keep a careful eye on how the cross reference displays things ...

notice that N7:21 is shown as TWO entries – and notice that one of those is shown as a "FILE" with a length of five words ... (the "LEN:5" entry) ... so ... counting five words starting at N7:21 does indicate that words N7:22, N7:23, N7:24, and N7:25 are indeed being used in the program ... like I said, it's sneaky – but it's there ...

next item:

doing a "Find All" search for N7:22 comes up as a "Not Found" result ... that's because the find all feature is only a little bit more than a "text" search engine ... in other words, it doesn't have enough horsepower to know that N7:22 is a part of a "file" that starts at N7:21 ... since it doesn't find the precise text string "N7:22" that we searched for, then the results come up as "not found" ...

final thought for today: if it was "EASY" then everybody would be doing it ...

 

[Lakee911]

I do see that LEN:5 thing in the cross reference box now. I had never noticed it befre. Also, I apparently missed the "the 5 integer words of the CONTROL BLOCK" in your write up. I think I'm squared away now though.

Thanks so much for the help...I'm sure I'll be back.