Hi all, I’m evaluating Ignition and have a question about it’s ability to directly reference bits within a DINT tag with in a PLC specifically for ControlLogix/CompactLogix systems.
For example:
PLC_DINT_Tag. So 32 possible bit references.
I use DINT tags for SCADA animations to reduce tag counts (for those SCADA products that use # of tags for licensing). So PLC_DINT_Tag may contain 32 various animations for SCADA within a single tag.
In another SCADA program, I could reference at the bit level by appending the bit reference to the tag within the SCADA program:
Can you achieve this same effect with Ignition? If so, what is the Syntax? I really don’t want to have to create separate tags for each bit within the DINT tag.
I found a DINT tag in my PLC, browsed to it via the OPC browser, dragged it into my SQLTags folder. I now have a DINT (int4) tag called “Tagname” in my project.
When I try to bind this tag to the visibility property on a rectangle, the following works:
Expression: {Tagname} = 1
Great, I can change visibility based on an integer value.
When I try to directly reference a bit, I get an error. I choose the “tag” option to bind the visibility to “Tagname”, then change the tag to “Tagname.0” to reference bit 0 as a true/false. I get the following errors:
“Tag Property ‘0’ is not a valid property”
“You must choose a tag or tag property in the tree”.
Thinking there must be a way, I edited the “Tagname” OPC Item Path to be Tagname.0, now this works when I bind “Tagname” to the visibility property of the rectangle. However, this isn’t the desired function as “Tagname” is now just a bool as it is directly referenced to the .0 bit in “Tagname”, and can no longer access the other 31 bits unless I make specific tags for each of those bits.
In order to do this, you MUST specify a SQLTag in Ignition for each BIT you wish to reference You cannot do a bit reference like this on the Ignition SQLTag name, it as to be done at on the tag OPC path.