RsLogix 500 Configuring PLC and Expansion Modules in I/O Configuration
Today we are going to talk about how to configure a new PLC and configure it’s I/O in a new RsLogix 500 project.
Start with opening RsLogix and creating a new project. Then scroll down to the processor, in our case a Micrologix 1400 Series B.
Now double click on the I/O Configuration. Adding expansion modules is as simple as double clicking the part number of the module you want to add. We are going to add a 1762-IQ16 to slot 1, a 1762-OW16 to slot 2, a 1762-OB32T to slot 3, and a 1762-IF2OF2 to slot 4.
Now how to address them. Let's start by opening our input and output data tables. I’m going to arrange them so that we can see them both at the same time. There is a method to their addressing but let’s walk through a few addresses first then go through how it works.
The base unit’s 20 input points and the 12 output point are considered slot 0. The Micrologix is broken up into 16 bit blocks so the first 16 inputs are I:0.0/0 through I:0.0/15 and the last 4 inputs are I:0.1/0 through I:0.1/3. The outputs are O:0.0/0 through O:0.0/11.
The addressing of the other slots is just as easy with a small catch. In every PC I’ve ever seen, the default size of the data table obscures the far right column that identifies which slot goes to which address. Drag the data table view to widen it up so that you can see this column.
Now we can see slot 1’s 1762-IQ16 is I:1.0/0 through I:1.0/15 of the input data table and is not present in the output data table. Slot 2’s 1762-OW16 is not present in the input data table and is O:2.0/0 through O:2.0/15 of the output data table. Slot 3’s 1762-OB32T is similar to slot 2 having no presence in the input data table but has two rows in the output data table, O:3.0/0 through O:3.0/15 is the first 16 outputs and O:3.1/0 through O:3.1/15 is the last 16 outputs. Slot 4 and is easier to view if you change the radix to decimal. Then the first analog is I:4.0 and and the second analog input is I:4.1. The first analog output is O:4.0 and the second analog output is O:4.1.
So here is how it works. An input address begins with an “I”. An output address begins with an “O”. Then there is a colon “:”, then the slot number, then a period “.”, then a word identifier which breaks up the data into 16 bit blocks. The first 16 bits will be “0”, the next 16 will be “1”, etc. Then there is a slash “/” then the specific bit identifier. If it is analog, then you don’t break it down the the bit level, only the word level.