Rockwell's Micro800 family of low cost programmable controllers have very appealing price points.

But when it comes to usability, many of us have been reluctant to trade our familiarity and efficiency with RSLogix / Studio 5000 for a few hundred dollars in savings on low I/O count projects.

That familiarity extends to Logix's naming convention used with local I/O, which is drastically different from how the Micro800's embedded I/O is defined.

At first look, the Micro800's _IO_EM_Dx_Ox embedded I/O tags names just look plain odd.

Now I do understand that start starting a tag with an underscore will allow it to be displayed before tags starting with a letter when sorted alphabetically.

That said, anyone who's ever written a sorting routine knows it's a fairly simple task to sort by “type” first, and then by “name,” which eliminates any need to use the first character to force a particular sorting order.

So while using the “first letter” to force the sorting order of files and folders on a hard drive can be useful, it seems totally unnecessary to use it for Micro800 embedded I/O tag names.

That said, the good news is that creating aliases for these embedded I/O tags couldn't be easier.

Unlike Logix, which requires you to create a new alias tag before aliasing it to an existing tag, in CCW you just type in your desired alias to the right of the IO tag name and you're done.

So while the odd naming convention used for Micro800 embedded I/O makes Logix programmers like myself cringe, the fact that aliasing them is so easy goes a long way to making up for it.

That, and I have to say I'm loving the Micro800's freeFBD editor, but we'll save that for a future article…

If you'd like to see how aliasing Micro800 embedded I/O actually works, check out my video below.

And if you know anyone who needs to get up to speed on the Micro800 quickly, please pass on a link to my affordable Micro800 / CCW training course Nano Basics Course.

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Shawn Tierney
Automation Instructor and Blogger (post views: 1,001 views)

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Forum Comments:
  1. Hi,
    I have two problems with micro 850 tags! I extract the tags from program but:
    1- there is no I/O in the tag list ! since they are available in global variables
    2- the tags are totally different with standards Allen Bradley Tags for example this is a standard tag!
    TAG R3_A110511_CAB02_VAC_K01:15:I AB:1734_IT2I:I:0 (ExternalAccess := Read/Write)
    and this is what I extract from micro 850:
    finalpresure REAL Var ReadWrite 0.046
    How can I have standard tags? or if it is not possible, How can I use these tags in the network ?!!
    tanks in advance
    Good afternoon vahhag,
    Sorry I missed your post earlier in the month - not sure how it slipped by me 🙁
    Tags in the Micro800 series are much different than the Logix series, which is what you are seeing.
    I would suggest contacting your software vendor to find out what format they support. For instance, if you are using a ViewStudio this guide will help with the export import:
    Also keep in mind the connection limits:
    Good luck,
    Shawn Tierney,
    Instructor at

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