Findb Limitation In a d4-450

[ModeManuel]

Hi, I'm trying to use this instruction as a hudge compare (multiple words) ... it work the purpose is to know if someone change the value in a table of 30 bytes or 15 words it work well but I don't know why it stop working at bytes 24 the code is str sp1 ld k1E ( step 1) ( number of bytes hex) ld kF (step 2 )( lenth of table words hex ) lda o2016 (step 3) (ending location) lda o2000 ( step 4) (starting location) findb v2303 (step 5) (starting location of block) and sp53 (logic error flag) out c4 ( On= block not found in table, off= equal) step reference to the instruction chap. 5 it is hard to explain why but, if bytes 0 to 24 starting at v2000 are not equal to bytes 0 to 24 starting at v2303 the flag logic error sp53 is on ...yes good ! but bytes 25 to bytes 30 won't affect sp53 any one know why ? thank for your anwser

[b_carlton]

I have used AutomationDirect products including this one but have never used this command. Your arguments look proper according to the documentation. Why don't you try posting at the AutomationDirect forum? You may get better answers there.

[ModeManuel]

Hi, you're probably right, I'll gave you feedback on this .... thank for your check

[atanas]

Hi ModeManuel, Perhaps it has something to do with the numeral systems. 30 octal = 24 decimal. The octal numeral system is native for PLC Direct. Your code looks OK- adjust the constants Regards, Atanas

[b_carlton]

Nothing much more to add except that I replicated your findings with the FINDB command on a DL06

[b_carlton]

ModeManuel - did this get resolved. I didn't note any postings on the AD forum. I haven't used this instruction before but if I do I want to know any official limitations that AD may have which aren't in the manuals.

[ModeManuel]

Sorry if I didn't gave you feedback before ... I didn't post on the plc direct forum like expected and I finaly had enaugh to make it work even with that restriction. I shortened the recipe name lenght from 30 char to 24 thank's for you're help