Logix5000 Codeing

Afternoon all,

In logix5000 can you create a function block from code written in ladder.

Siemens is my standard and i would like to use code ive written and create a block using indirect addressing (in the block) and attach my global tags externally once i put my new block in Rockwell equivalent of OB1??

Hope this makes sense,

Thanks guys

Look into AOIs in RSLogix. (Add On Instructions). May be the closest thing to a Siemens FB available. I'm not as familiar with AB as Siemens, so could be wrong.

Hi


Tim is correct with the add on its as close as you will get.
ob1 in Allen Bradley is call main routine in ab terms as this is where you scan will start and finish.
You can create local tags within your Aoi as you would use temp bits in Siemens.
There are no real sfb in Allen Bradley but I suppose if you download some of the ones Allen Bradley have in the web site it's as close as it gets.
There are no db in ab just a tag data base( like the symbol table) which can be local or global as in ab.
You can also do Indirect addressing but you don't create a pointer the same way.
You can have a lot if ladder files (programs ) or again as close to an ob as I think anyway.
Timers are also different as they mostly time up not down .
You can have arrays also, items are mostly double words (dints) and you don't have to watch for memory overlap or create a cross reference.

Donnchadh

AOI's are handy to use, but cannot be edited online. So if you need to make changes you have to go offline, make your change, then download the project to the controller. As long as you select "Upload all tag values" when you save everything will be as it was before you went offline.

Hi

Can fb's be edited on line ? I did not think so with out have to change ever FB on line but please correct me if I am wrong.

Donnchadh

You can make a change to a FB and then download it immediately as long as you do not make a change to any of the variables. Temp variables are ok though to change. Otherwise you need to update the DB's of the FB and download them to the controller at the same time as the FB.

Hi

I know it's not the question but it may help gaz.
What if you have a number of the same type if FB will you not have to download
That number or at least edit all the fb if you added a new input parameter

Donnchadh

Gaz has an AB question. Do you mean AOI instead of FB Donnchadh?

Hi jd

Really it's the same for both i think and I was just pointing this out to gaz expect in ab as you have pointed out you will have to down load the hole plc program as in Siemens you can down load 1 at a time but I am not sure if you would fault the Siemens plc.
I was really just trying to compare both for gaz as he seems to be a Siemens plc guy and not ab

As always I am open to correction

Donnchadh

Donnchadh said:

Hi jd

Really it's the same for both i think and I was just pointing this out to gaz expect in ab as you have pointed out you will have to down load the hole plc program as in Siemens you can down load 1 at a time but I am not sure if you would fault the Siemens plc.
I was really just trying to compare both for gaz as he seems to be a Siemens plc guy and not ab

As always I am open to correction

Donnchadh

Click to expand...

Cheers for the clarification guys, In classic S7 you can download 1 block at a time but not in the new portal V12.SP1. I sort of expected that in AB as well, TIA portal is trying to be more AB (Maintenance engineer friendly) just a note once you update a FB in Siemens and add extra IN/OUT's you have to update the Called blocks Consistency and also download the updates, if you dont do it in the correct sequence it will crash a 300 PLC if online.

Once again PLCs.net it much more informative than the F1 key and help files, much easier to get the correct info.

Thanks