chelton

I would assume IO_Rmc_Data is an index for a 10 element array of Data. The forrmula is creating a repeating 0-9 output. So if when IO_Rmc_Data = 9 , the next time the CPT is executed (IO_Rmc_Data+1) MOD 10, would equate to 10 MOD 10 which = 0

Using your example JSR(_Fx,2,21,MstrDmd,lbdPosGas) Subrutine _Fx is called with input parameter 21 and MstDmd and returns lbdPosGas. In the Subroutine, Rung 1 will evaluate to 21-1 AND 7 = 4 Rung 4 will then be evaluated because FxNo is between 17-24 so the COP will copy 32 elements from  FX17_24[4,0,0] to FxX0  ...... That's as much as I can explain without knowing the value of MstDmd.    

All the CPT instruction is doing is making the range of FxTblStart from 0-7 from an input FxNo from 1 - 48  

what else is writing to FxTblStart?   How can FxNo-1 AND 7 = 1?    

You would still need to loop through the entire array to calculate the standard deviation each time the average changes. @Criticore how often are you needing to update these values?

I would look at using a FAL instruction for your calculations and setting the mode to the number of iterations you want to perform each scan. If for example you set the mode to 50 your calculations could be completed by the 6th scan.

I hope you didn't get the same surprise I got arriving on site unable to fire up your VM. It was fun trying to get cellular reception to download the update lol.

Just a warning for anyone using a mac for their VM's . VMware fusion version 11.5 is not supported by the latest OSX "Big Sur" If you update your OS  you will get no warnings and you will find that fusion no longer works, you will need to upgrade fusion too. 

I agree, thanks for posting the outcome. Out of curiosity did you find if the db module was doing anything?

@spark man even though there is nothing in RAM your program could still be on the ROM. Here's a sample output of "Call 81". It tells me there is 1 program in ROM.   You can then change the console to look at the program by typing ROM 1 then list the program stored. Hope this helps.

From command mode enter "call 81" This will tell you if there are any valid programs stored in the eeprom

I'll rephrase what I said. Judging by the response you receive from db module it appears the memory is corrupt, and therefore not operating. This does not mean the module does nothing, but that something in the plc program may not be functioning correctly, because the db module is not running its program.

You can use the ROM and RAM commands to load the program from the chip. Read the manual first though. 

Definately looks like the db module program is corrupt. Why not disable the btr/btw to the db module and see if there is any effect on the machine. Judging by the output I'm guessing it's doing nothing.

Control C will break the operation and stop the program, entering command mode. You can continue from where is stopped by typing "cont" or let it start from the beginning by typing "run"