While the MicroLogix 1000 is the least expensive RSLogix based PLC from Rockwell Automation (starting around $150,) it's also the most limited.
That in mind, in today's article we'll compare the MicroLogix 1000's “Data Files” with the MicroLogix 1100's, as they are the only two MicroLogix PLCs supported by the free version of RSLogix Micro we discussed last week.
When you create a new MicroLogix 1000 program, you'll notice that like other MicroLogix, and the SLC-500 and PLC-5, you have several Date Files created for you automatically, as shown below:
However, unlike those other PLCs, each data file in the 1000 has been expanded to its maximum size, and can not be expanded past it.
What that means is, if you run out of Bits, Timers, Counters, or Integers, there's nothing you can do to add more as the “Elements” field is grayed out:
However, when you create a new program for the 1100, the first thing you'll notice is an extra data file, the F8 Float file.
This data file, which most other MicroLogix, SLC-500, and PLC-5s also support, is of the IEEE 32bit Single Precision Floating Point Data Type, and is perfect for storing numbers which contain fractions:
And unlike the 1000, with the 1100 you can also create new data table files by right clicking on Data Files:
Some of the new data file types you can create include Long (32 bit signed integer,) String (82 ASCII character,) MSG (for message instructions) and PID (for PID instructions.)
And while each file defaults to only one element, you can expand each to up to 255, however the 1100 does not have enough memory to have all 254 data files contain 255 elements:
And that's it for our look at the differences in Data Files between the MicroLogix 1000 and 1100.
If you'd like to learn how to use and program both the MicroLogix 1000 and 1100, I suggest checking out my affordable MicroLogix video training course at PLC Basics Second Edition
And to see a video of the above comparison, check out the below episode of The Automation Minute:
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