sum

hi,
I wanted to know if there is something wrong with the modification that i made a few days ago.
I changed a CPT function in an AB SLC5, that only made the sum of 5 N (from N31:10 to N31:14) to this new format (in the attachment) in which I add only if a bit asociated with the value is checked.

thanks in advance.

This display would be correct if conditions changed (something were writing a '1' into N31:25, the values of N31:10 - 14 were overwritten with '0' or the enabling bits (B30:1/0-4) were cleared) somewhere between the execution of this rung and the end of the scan.

Looks like values will not be added unless the associated bit is disabled. Should work just fine. I don't know what value or purpose is served by N31:22, it must be the 80% referred to in the comment, but looking at the data ( 0 ) in the destination, N31:22 must contain a zero if this pdf was captured from online data.

always

N31:25 is always going to be 0. Look at the start of the rung.

Guest1 said:

N31:25 is always going to be 0. Look at the start of the rung.

Click to expand...

Not true - if any of the bit instructions are evaluated true, then the addition on that branch will happen increasing N31:25 by whatever is in the appropriate N31:10-14 register . . .

Marc



PS: On this scan everything in N31:10-14 is zero, so you are correct for this scan, but since we can't see the controlling logic for these registers, I see no reason to expect N31:25 to always be 0.

Given this particular screen capture with the conditions shown - if nothing after this rung were affecting N31:25 then its value should have been '0', but it shows '1'. Thus my comment indicating that, as far as this particular capture is concerned, something else between this rung and the end must have affected the values shown.

bernie_carlton said:

Given this particular screen capture with the conditions shown - if nothing after this rung were affecting N31:25 then its value should have been '0', but it shows '1'. Thus my comment indicating that, as far as this particular capture is concerned, something else between this rung and the end must have affected the values shown.

Click to expand...

. . . or this rung is not being currently scanned (in a conditional sub / in a JMP / etc.), and in a previous scan, something in one of the N31:10-4 registers was a '1'.

Marc

hi,
No the rung was not taken online. It keeps values from the las operation, or god knows from where.
The total number, is the total adition of the times of 5 diferent steps. The times and conditional bits are send with a recipe, and I add them if they are going to use time in the selected step.
Then I use that value, and substract the current time and show in a Panelview the remaining time.
The 80% is used in case of fault, and return to the process, to decide if this particulars 5 steps continue or I jump directly to the next sequences.

Thanks to all for the inputs. Like I said before, just wanted to know if the rung was making the job correctly

So - you download your recipe which sets (one or more) of the appropriate bits (B30:1/0 - B30:1/4), and the appropriate times into N31:10 - N31:10-14, then this rung combines that information to get a total time . . .

If I understand you correctly, it should work fine as written. Be careful that the rung is being scanned appropriately and that you aren't adjusting N31:25 elsewhere . . .

Marc