long integer value and JAZZ

[vaitehs]

I have one aplication ,where i need to do calculation and display on the lcd the result .With integer value up to 32767 is everithing ok ,but with calculation up to 100000 i have a problem

i sow the example in the help menu but i can't understand th logic for example how to display the result of 20000X4=80000 on the screen :( may be I am dumm to understand the logic

Any help is welcome .

[Walkerok]

I am not sure what you are exactly doing, but the use of the long integer bit only allows you to perform math calculations and operations on a net and store/manipulate the values into 2 consecutive MI locations. I do not believe the long integer function will allow you to display a value that would be larger than a standard single MI's 16 bit space since there is no way I can find to ask the variables list to pull two MI locations of data. I would recomend that you take your starting value and then do your math calculations using the long integer function and then after all of your math calculations are complete store the final value into a single 16 bit single MI location (if possible). If this is not possible I would say that you will have to switch to a higher level PLC than the Jazz or M90/91 that will allow long integers in regular calculations and screen data.

One thing I have found that is unclear in the help files is that every single math function performed will require the insertion of the SB82 bit just before it. Even if multiple math calculations are all done on a single net the SB82 long integer bit will only apply to the calculation imediately following the SB82 bit.

[Joe Tauser]

This is the problem with the Jazz- people start pushing it to places it can't go. The best way to work with this PLC is ignore the fact that it can do limited long integer functions and approach your application from an old-school 16 bit mindset. Then you won't be tearing your hair out trying to move numbers around in a way that can't be done. There are ways to work with large numbers in MI land - give us some more details on exactly what you are trying to do and we can help.

I've done three projects that began with a Jazz because of the attractive price and then replaced it with a V130 because the calculations and display required long integers. I just always start with a V130 now.

Joe T.

[transpondster]

well its doable, off course documentation should be more clear that before each 32 bit operation there is need to set sb 82 and IMHO that part of reseting it for store operation is illogical or at least it should have some other sb.

[frk]

I understood that u had to use the SB82 before math compare and store operation. I understood that u had to use the setting actual result to a bit after compare. But does anybody knows what means the help desription in store operation that tells us about possibility of output on the LCD. How can I get it into the display variable MI. Is there some system integer and use store with SB82????? I need to use the jazz like counter of the goods but 16 bit value is not enough. So I wanted use this 32 bits possibility...