How To Clear Boolean Array?

[evanmars 0]

I have an array of BOOL (My_Bool_Array[32]). How to I set all elements to 0? RSLogix 5000 Compact Logix Edited 9 Jul 2013 by evanmars

[Michael Lloyd 85]

One at a time unfortunately

[evanmars 0]

Thanks, that's what I figured. So I just did this: LES Clr_Index 32 BST OTU My_Bool_Array[Clr_Index] NXB XIO My_Bool_Array[Clr_Index] ADD Clr_Index 1 Clr_Index BND Edited 9 Jul 2013 by evanmars

[evanmars 0]

That didn't work because RSLogix5000 evidently doesn't use short-circuiting. Although I only wanted to execute the rung when Clr_Index < 32, it still tried to read into My_Bool_Array when Clr_Index = 32, so threw the PLC into a major fault. So I did this instead: BST OTU My_Bool_Array[Clr_Index] NXB XIO My_Bool_Array[Clr_Index] LEQ Clr_Index 30 ADD Clr_Index 1 Clr_Index BND

[waterboy 7]

Would it not be possible to convert the 32 bit bool array into a single DINT and change the address of the bits to DINT.X ? Then you could just write a zero to the DINT and be done.

[evanmars 0]

Thanks. Yeah I figured that out a bit ago and that is what I ultimately went with.

[daba 4]

The only way I know of doing this is to make your BOOL Array a member of a tag of a User-Defined Data-Type, then you can use COP CPS and FLL Before toggling Clear_BOOLs After toggling Clear_BOOLs Note that a Length of 1 for the FLL instruction clears all 1024 BOOLS in the array Edited 9 Jul 2013 by daba

[waterboy 7]

If it makes you feel better, a bool and a DINT both use 32 bits of memory. So you are being more efficient !

[Knuckles 0]

You can masquerade the BOOL array data type as a DINT array data type while passing it to a subroutine as a parameter. Pass the BOOL array through a JSR as a parameter. Inside the subroutine, receive the parameter as a DINT array. In your case, a single DINT. Inside the subroutine, FLL the DINT array with zeros. In your case, MOV a zero into the DINT. When the JSR returns, the BOOL array will be zeros.