RSLogix 5 MOV function question

[sparkytex]

Attached is an image of rung 43 on LAD10 of our digester program. In the MOV instruction at the end of the rung, the source address is something I've never seen before - "SOURCE N7:[N7:3]". How exactly does this work?

Also another question while I'm posting a thread. How do you go about printing of programs or specific Ladders from RSLogix5? Do I need to have a printer that's connected to the same LAN network as the PLCS. Or is there a way to turn the program into a PDF file or something in order to print off on another computer that's not on the PLC LAN. I got a request to print "LAD10" from one of our programs and I have no clue how to go about it.

thanks, TEX

 

[Mike_RH]

This is indirect addressing.
The source address in the mov depends on the value of N7:3.
So if N7:3 = 5 the source address is N7:5.
There is (I think) an option to have indirect addresses displayed as you have it or as the final address.
It is possible (and likely) that the indirect pointer changes every scan.

 

[bernie_carlton]

As far as printing I have CutePDF installed which installs a "Printer" which creates a PDF file instead of sending it to a physical printer. There are other similar freeware options.

I don't have RSLogix5 available but RSLogix500 makes it possible to print out single routines. I use 'File' - 'Report Options' to specify exactly what is to be printed.

 

[sparkytex]

Thanks Mike, This is actually a pretty cool trick to have in the folder for the MOV instruction.

 

[bernie_carlton]

Actually almost any place that a number appears in an address it can be replaced by [Address Reference]. There are some exceptions.

Note that using an indirect reference increases the execution time (because of the extra memory access and computation of the actual target address).

You cannot nest them though (an indirect inside of an indirect).

 

[sparkytex]

As far as printing I have CutePDF installed which installs a "Printer" which creates a PDF file instead of sending it to a physical printer. There are other similar freeware options.

I don't have RSLogix5 available but RSLogix500 makes it possible to print out single routines. I use 'File' - 'Report Options' to specify exactly what is to be printed.

Bernie where did you download the "CutePDF" file? thanks!

 

[Operaghost]

CutePDF is a program you install on your PC. You can get it from here.

http://lmgtfy.com/?q=cutepdf

OG

 

[bernie_carlton]

Just Google "Cutepdf". The free version will require downloading of a helper file. The instructions are on the site. The result is just another "printer" in you list. You use it just like any other printer except the result is going to a file.

And another warning on the use of indirect addressing. You must be absolutely sure the indirectly specified address actually exists. The compiler can't catch this. If it points to non-existant data you'll have a fatal runtime error.

 

[sparkytex]

awesome, thanks again for the help guys!

 

[daba]

Indirect Addressing.....

You can indirectly address the file number, element number, and bit number.

You can have up to 2 indirect references in your reference.

examples of valid indirect addresses...

N15:[N7:0]
N[N7:0]:45
N[N7:0]:[N7:1]/3
N[N7:0]:45/[N7:1]
N20:[N7:0]/[N7:1]

In the above examples, if N7:0 = 20, and N7:1 = 7 at the time of the instruction execution, the effective addresses are respectively....

N15:20
N20:45
N20:7/3
N20:45/7
N20:20/7

 

[sparkytex]

Indirect Addressing.....

You can indirectly address the file number, element number, and bit number.

You can have up to 2 indirect references in your reference.

examples of valid indirect addresses...

N15:[N7:0]
N[N7:0]:45
N[N7:0]:[N7:1]/3
N[N7:0]:45/[N7:1]
N20:[N7:0]/[N7:1]

In the above examples, if N7:0 = 20, and N7:1 = 7 at the time of the instruction execution, the effective addresses are respectively....

N15:20
N20:45
N20:7/3
N20:45/7
N20:20/7

Great info!! thanks

 

[Lancie1]

You cannot nest them though (an indirect inside of an indirect).

But you can put an indirect address inside of an indexed address (the indexed indirect address mode). I have never had a desire or need to get that complex, however.

 

[Lancie1]

I don't have RSLogix5 available but RSLogix500 makes it possible to print out single routines.

RSLogix5 has an almost identical "Report Options" menu. To print only the LAD 10 file, first de-select everything on the Report Options EXCEPT "Program Files". Then click "Program Files" on the top menu of Report Options, then select only LAD 10 in the "Print List". Make sure you click "Apply" on the Report Options page to lock in your new print selections.

 

[sparkytex]

RSLogix5 has an almost identical "Report Options" menu. To print only the LAD 10 file, first de-select everything on the Report Options EXCEPT "Program Files". Then click "Program Files" on the top menu of Report Options, then select only LAD 10 in the "Print List". Make sure you click "Apply" on the Report Options page to lock in your new print selections.

I Just figured this out and came on here and realized you explained it, thanks!