I worked at a plant that the senior programmer would just take out the JSR of aPLC5. For whatever reason he wouldn't delete the code. When the power would cycle to the plant. One of us would have to go in and toggle every analog card to get the correct configuration in it. This is when I learned about prescan and having multiple BTW. Once I deleted the old code that wasn't being scanned the problems went away.
I learned a lot about what not to do vs what to do from the senior guy. I explained I like to understand why not just blindly follow. So I questioned why did he do XYZ vs ABC. Sometimes I got an answer of "Just because" other times it was a well thought out answer.
I learned that messaging between controllers is a very powerful and dangerous tool. Using a message write just pushes data into a controller. So 50+ controllers just pushing data into another controller makes it fun to find out who sent what. From what I remember a message write uses 1 or 2 less connections than message read. So they used writes to keep network traffic down.
I learned a lot about what not to do vs what to do from the senior guy. I explained I like to understand why not just blindly follow. So I questioned why did he do XYZ vs ABC. Sometimes I got an answer of "Just because" other times it was a well thought out answer.
I learned that messaging between controllers is a very powerful and dangerous tool. Using a message write just pushes data into a controller. So 50+ controllers just pushing data into another controller makes it fun to find out who sent what. From what I remember a message write uses 1 or 2 less connections than message read. So they used writes to keep network traffic down.