RSLogix5000 Aliasing Question

First time poster -- Great Forum!!

I am currently writing logic to move product from (8) packaging machines down to (6) palletizing robots. I am writing the code for the conveyor controls while the robot vendor is writing code for the robots, themselves.

One of my colleagues coordinated with the robot vendor, the naming of tags that reside in my controller that will be used by the robots.

For simplicity's sake, lets say that two pieces of data need to be moved into these tags for consumption by the robot PLCs -- Data_1 and Data_2.

Here's the problem: Had I named the tags, I would have created an array of (6) DINTs for each piece of data -- one for each robot. That way, I could use the Robot Number as the array index (subscript) for each piece of data. For example:

Data_1[0] for Robot 1
Data_1[1] for Robot 2
Data_1[2] for Robot 3
etc., etc.

Data_2[0] for Robot 1
Data_2[1] for Robot 2
Data_2[2] for Robot 3
etc., etc.

If I wanted to move data into the registers for Robot 1, I could simply use indirect addressing like this:

Robot_Num = 0
Data_1[Robot_Num]
Data_2[Robot_Num]

Instead, my colleague named the tags like so:

Robot1_Data[1]
Robot1_Data[2]
Robot2_Data[1]
Robot2_Data[2]

As you can see, the Robot Number is contained in the tag NAME, instead of the array subscript. I assume that there is no way to use the Robot Number as the tags are currently named, correct?

I'd like to be able to alias the array elements he created with my own, but I'm sure I can't do that in CLX:

Data_1[0] aliases Robot1_Data[1]
Data_1[1] aliases Robot2_Data[1]
Data_1[2] aliases Robot3_Data[1]
...
...
Data_1[5] aliases Robot6_Data[1]
================================
Data_2[0] aliases Robot1_Data[2]
Data_2[1] aliases Robot2_Data[2]
Data_2[2] aliases Robot3_Data[2]
...
...
Data_2[5] aliases Robot6_Data[2]

Anyone have any wisdom to share? My current options are:

1) Coordinate with the vendor and change tag names (??Likely??)
2) Write 48 "what-ifs" in logic (6 robots x 8 machines)

Thanks for any help you can provide!

You cannot alias array elements in Control Logix. You can write some dummy tags that alias to the Robot Tags, then manually map them to your array in a subroutine somewhere (I had to do that once), or coordinate with the vendor.

$

Your best bet is to talk nicely to the robot vendor - maybe set up a two-dimensional array (e.g. Robot_Data[1,2])

recondaddy said:

One of my colleagues coordinated with the robot vendor, the naming of tags that reside in my controller that will be used by the robots.

Click to expand...

[joke on]

Shoot your colleague!

[joke off]

Thanks for all your replies, everyone.

I have decided to use dummy tags and map them to the poorly-named tags.

I was so fixated on using alias tags that I completely missed the fact that I can do a "poor-man's aliasing" by moving data from dummy tags into the bad tags, using ladder logic.