I was nineteen years old the first time I ever used a computer and learned the possibilities of what would be my career ahead, but young people today have an advantage.

They have used phones, tablets and laptops since a very early age. All it takes is a little interest and they have the background to easily jump into a field in what is known to them today as STEM (Science, Technology, Engineering, Mathematics)

My daughters are a testament to this and since they have shown interest in the S7 1200 PLC I have been working on, we have worked on a few things together to both spend quality time as well as see what sparks interest for them in the years ahead.

Siemens Stack Light

We have a Siemens Stack Light (part # 8WD4408-OAE) that we want to connect to our S7 1200 PLC.

Wiring the Lights

A look at the manual shows us how to connect the stack light to our 24VDC Outputs as follows:

  • 24VDC + from our power supply connects to the L+ terminal

  • 24VDC – from our power supply connects to white wire of stack light

  • 0 – Output 0 connects to our brown wire of stack light (RED LIGHT)

  • 1 – Output 1 connects to our green wire of stack light (GREEN LIGHT)

Actual Wiring of outputs

Writing Her First Logic

What we decided to do was write logic that would make the lights blink alternately.

Brooklyn created a timer that would run continuously. She then used two “IN_RANGE” instructions to evaluate the “Elapsed Time (ET)” of the timer and turn on each output for one second intervals.

We also adjusted the timer preset “PT” and In_Range “MIN” and “MAX” parameters to make the lights blink at different intervals.

This helps them see physical change in the real world as a result of the program changes that they make and you can see their minds working as they catch a glimpse of what the possibilities are in the world.

Let There be Light!



When I discovered control systems and how much I loved to “Make Things Go” for a living, I have always enjoyed sharing it with others.

While I would never “push” a career path on my kids (nor anyone else) that they would not want to become involved in, I do love to share the experience and the exposure to them.

Who knows, maybe they just had a quality afternoon with ole’ dad and maybe a seed was planted for a future path. Only time will tell.

Written by Brandon Cooper
Senior Controls Engineer and Freelance Writer

Have a question? Join our community of pros to take part in the discussion! You'll also find all of our automation courses at TheAutomationSchool.com.

Sponsor and Advertise: Get your product or service in front of our 75K followers while also supporting independent automation journalism by sponsoring or advertising with us! Learn more in our Media Guide here, or contact us using this form.

Brandon Cooper


Please enter your comment!
Please enter your name here