Studio 5000 Power Up OTE vs OTL OTU of a Controllogix Compactlogix

We are going show you some very important differences between to OTE Output Energize instruction and the OTL/OTU latch unlatch instructions that happen when power is cycled to the PLC.

An OTE output energize will be off on power up where as the OTL/OTU will remain in it’s last state on power up.

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[brstilson]

I've been programming over 15 years and I never knew this! It never really came up for me before so I never thought about it. There really is always more to learn no matter how long you've done this.

[jerrywyatt]

Always something to learn. I'm finishing up a project and was concerned about my latched outputs when my emulator powered the dang things on at startup. I did use the S:FS to unlatch before watching this video, but now I know the how, and the why.
Thanks Tim!

[marshal]

Thanks a lot Tim this is just what I needed to know. Your the Best!!!

[johnrece]

That answered my question, thank you sir!

[marshal]

Im building an elevator system in my home and it uses multiple inputs and outputs for limit switches, door sensors and obstacle detection

[jonnymac]

Hell yeah man. I appreciate the wise words.

[matthewfisher]

Why not use NOHC or NCHO to eliminate your the pre and post scan variables?

[marshal]

Ok Tim, I tried the example with the S:FS instruction on my (U) rung but have multiple inputs via branching. When I added the S:FS branch it did not show First scan when hovering the mouse pointer but I got an error Invalid Direct File Offset?? Can this be used on multiple branches on a (U) rung??

[nassimlamrous]

I can't find the first scan bit in my controller