Rslogix 5000 - indirect addressing in local io tags

[Quinn Mallory]

Hello,

I'm trying to create IO tags that will allow I/O to be changed via the HMI once the system is deployed, and without needing to connect via PC.

I've got "Local:1:I.Data.[SYS1.IO.T1]" working as a tag, allowing the terminal to be changed.

But, "Local:[SYS1.IO.S1]:I.Data.[SYS1.IO.T1]" is seen as invalid. This portion is needed as it would allow the slot to change as well as the terminal.

 

[A_G]

Not sure if RSLogix will allow you to do this.

Sounds like you want to change IO mapping directly from the HMI. This could get risky in my opinion. What happens if the operator accidentally changes the IO mapping? For example, an output that previously controlled a valve can be changed to control a pump etc. What if an input that was used for the Emergency Stop is accidentally remapped? Sounds like it could cause some issues. Just some things to consider.

 

[dmroeder]

It's not letting you because Local: is not an array. Same reason you can't indirect with something like: Tag1, Tag2, Tag3

Create an array, something like IOMap[n], move each local I/O word into the correct spot in this new array tag, then you will be able to double indirect with IOMap.

 

[daba]

A colon in a tag-name is not a delimiter, and anything either side of it cannot be referenced indirectly.

Local:3:I is a valid tagname, and in its entirety, it points to the module-defined tag created on insertion of a module that has input data, into slot 3 of the I/O Config tree.

The slot number cannot be dynamic, so you cannot indirectly address slot "n".

You can create UDTs of identical structure as the module-defined tags, and use code to manipulate the elements within, using COP or CPS to populate or read the data ....