User manual

Publication LOGIX-AP010B-EN-P - May 2010 41
Software Conversions - Program Structure Chapter 2
Logix Aliasing
The difference between Step 5 and RSLogix 5000 software is the RSLogix
5000 software uses a feature called aliasing to assign more intuitive names to
I/O, which makes for more user-friendly programming.
An alias can be created for each I/O point and this alias will contain the same
value as the associated I/O point.
When writing code, the programmer can use the alias name instead of the
address location. The alias name can be up to 40 characters in length.
Use aliases in the following situations:
• Program logic in advance of wiring diagrams.
• Assign a descriptive name to an I/O device.
• Provide a simpler name for a complex tag.
• Use a descriptive name for an element of an array.
Example
If the 1st input channel is connected to the feedback signal from Pump1 then
the following alias can be created by right-clicking on the tag assigned to this
address and choosing
New tag which aliases “Local:1:I.Data.0”
from the pull-down menu as shown in the window below.