PLC Timer Basics Question

Hey everyone, I'm a new user here and new to PLCs . I'm trying to teach myself PLC programming and have run into a snag using counters. I am using an old SLC 100 and am trying to program 3 different lights to come on at different intervals. Here's how it is layed out. I need someone to give me a sampe ladder to go by if possible. I'm getting this out of an old programming manual, but there is no answer key.

1st light is off for 8 sec. and then on for 8 sec.
2nd light is off for 4 sec. and then on for 4 sec. for 16 seconds.
3rd light is off for 2 sec and then on for 2 sec. for a total of 16 seconds.

Also, I would like this to reset itself and continuously run.
Any help? I'm lost.....Thanks a bunch.....

Hello Fafnir, and welcome to the forum. First, do you have the actual SLC100 controller, software and interface module in order to actually test your solution?

If not, you may want ton investigate learning on another platform, perhaps even an online simulator.

If you do have everything you need, I think I can provide some examples.

Paul

Yes sir, I sure do. I appreciate the help......

Ttt

I just noticed that I said I was having problems with counters, but I'm having problems with TIMERS--Duh......thanks

See if this manual is the same as what you have:

http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1745-um001_-en-p.pdf

It talks about timers in chapter 6.

All timers in a SLC100/150 are retentive. This means that they hold their accumulated values even when the timer rung goes false. The accumulated value will increase only while the rung is true, and freeze its present value when the rung goes false or even when the PLC is power cycled. Use the RST (reset) instruction to reset the timer when it is done, or when you need it to start over according to the needs of your program.

Also read through to page 6-4. On that page there is a pretty good explanation with examples and a timing diagram.

Paul