CompactLogix DINT bits

Ignition
1

Hello,
Posting this as I can see there have been many discussions around accessing bit value's of DINT's.
I am using a Allen-Bradley CompactLogix L32E (v15 f/w) and Ignition 8 to build some an app. I have created dynamic UDT's to access the individual bits of any DINT tags. I noticed however, that if any of the DINT's in my PLC are configured as arrays (even if only 1 array) then I can access/browse the individual bits directly within ignition, no UDT or creation of separate tags required.
Just wondering if this is by design, bug or whatever may be the case.

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Edit: Moved post to correct Topic

2

This purely a browse phenomenon, and intentional. You can always use the bits of DINTs in OPC item paths by appending the dot and bit number to an integer type's item path. The array is confusing the browse operation to show these when it normally would not.

1 Like
3

Yes, that is how I've been doing it (thanks to a previous post of yours I found) but was wondering do I need to if I can just add these to my tag group using the browser within the designer.

4

I wouldn't make arrays just for this. (Adds a smidgeon of overhead in the driver unless you are going to be using more than 32 bits anyways.)

For any significant quantity of tags in patterns, you should be using Ignition UDTs anyways....

1 Like
5

Thank you Phil