Compressor Ex 2- Logixpro 500

I have completed Exercise 1, I believe correctly. Can anyone help me with exercise two? Not sure how to alternate the compressors.
I have attached a pic of my exercise 1.


Here are the instructions for the Lab:
http://www.thelearningpit.com/lp/doc/c2/comp2.html


I need help with exercise 2.

Thanks, Kelby

Kelby,

Your work looks good. Exercise #2 is just another turn of the screw. In order to make this work; you’re going to need a minimum of 3 components. 2 objects to change states (the motors or lamps) and 1 object to keep track of the state change.

Take a look in the first rung of the ladder you just posted. The answer is right in front of you.

Do I need to use the Latch instructions? If so, I do not know how to use them.

Drop one in, click on it and press F1. The help files are very good on RSLogix.

Without speaking specifically about your application, there is never a place where you HAVE to use the latch/unlatch instructions. There are places where it's a good idea, and places where it's a bad idea, and places where it's neither here nor there and down to personal preference. If you can get good results using it, and it makes your code simpler and clearer, use it.

Oh, and welcome to the forum

As ASF has suggested, latches are not always the tool to use. Take a look at this 3 rung ladder using the LogixPro I/O Simulator. Hopefully it will inspire you. If not, we are still here for you.