LURBY

Micrologix 1100 Analog input programming

6 posts in this topic

Hopefully a simple, basic question.  I want to utilize the on board Analog input on my Micrologix 1100.  What is it called??  How do I address it on my program?  It is not an expansion card.  Just the built in inputs.

I am sure that I will have more questions about scaling and setting it up but I can't even get my foot in the door if I don't know how to find it.

Thanks,

Chuck

Share this post


Link to post
Share on other sites

For a start - in the manual 1763-RM001 search for 'analog inputs'. That will at least give you the location of the onboard inputs. The 1763-UM001 will show you the wiring.

 

Otherwise the 0-10 voltage input is presented as a number (0 - 1023). Use ordinary math for processing and comparison.

Share this post


Link to post
Share on other sites

Not sure if this against etiquette to jump into a thread that isn't mine, but i would be interested in the answer: how do I address the analog input? Which command do is I use in rs logix? 

I need something along the lines of "give me a true value if the voltage on the input is more than 3 volts"

Thanks in advance. 

Share this post


Link to post
Share on other sites

1st...identify the PLC part number you have to verify the terminals for analog input (not every PLC has built-in analog inputs available)

Next...with the PLC part number, track down the A-B literature (User Manual) for that PLC model

If the Micro has built-in analog input channel, it already has registers ready for your analog inputs.  If I remember right, Micrologix PLCs utlize Logix500 software and are input-based.

The user manual will guide you through the memory mapping; the analog input channels would be mapped to input registers (I:X).

I also believe the analog channels have configuration words (read and write words) to configure the analog channel (0-5V, 0-10V, +-10V, 4-20mA, 0-20mA, etc.).

So once you know what PLC you have, then once you have the user manual, and after you have researched the configuration words and what the word addresses are, and after you have wired in your analog input, then you can map the analog input and have it scaled using a SCL function block.  Going off of memory...a 4-20mA input will be coming in 0-32766 which you want to scale into whatever (degrees C or F [temp], inches/cm [height], etc.).

1 person likes this

Share this post


Link to post
Share on other sites

Thanks, for once something was easier than expected. :) One weird thing so: I'm using a mixrologix 1100 (1763-l16 awa) with 9 (or 10, don't remember) and two analog inputs. I:0/4 should definitely be digital, but that's where my analog signal us stored. I am using rslogix micro light, and I was only able to chose a generic mixrologix plc. I assume that is the reason? Will this cause problems when I or another person tries to modify the program with rslogix 500?

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now