How to Take the NX Safety PLC from Program Mode to Run Mode

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Valin's "How-To" video series on safety PLC's was very informative and saved me between 8 to 12 hours of reading tedious manuals. I was able to reference the videos as needed for clarification on questions. Going back though the videos I realized you had explained everything well, I just needed to see it once more. Very helpful!

John Peters, President
JJT Design
Hello this is Ray Marquiss, Senior Application Engineer at Valin Corporation. This video is going to show you how to take the NX Safety PLC from program mode through debug and then into the running mode where the machine will be shipped with the safety controller and the controller will operate to protect the machine.

OK, so if you've been following our other videos, you have a project, and it may look something like this.  But just due to different work I've been doing, it might look a little bit different than what you've got in yours, but it doesn't matter. If you've got a valid project, we want to make it so that now you can validate this project and run it automatically whenever the safety CPU is powered up. This is what the NX safety CPU looks like when it's brand new and powered up. You can see the lights flashing, debug, valid, run, and then all the lights on the input and output modules are flashing.
So I'm already on line. You can tell by this orange bar here. I clicked on this online button here. And now that I'm online, I need to go to the controller menu and change the mode to debug. You'll get a bunch of these messages that you can just answer “Yes” or “OK” to. If you have entered the password for the controller to protect it, then you need to enter that here.  It's a good idea during development just to leave the password blank until you actually deploy the system out in the field or sell the machine that it is on or whatever. OK, so now I'm in debug mode. And here you can see the LEDs on the controller. The debug light is on solid, the lights have stopped flashing and the run light is off. And you can see based on these two inputs being true that if the if the safety CPU is running then this output should be on, because this one means that it's going to automatically reset the output, meaning turn it on, when the PLC first powers up.  And then this one means it's going to reset whenever those input conditions are satisfied as they are here where the safety E-stop is true. So obviously the program is not running, so we're going to go to the controller menu. Go to debug and then start. We already went to the mode, changed it to debug.  The only other option there is for program. So we go to the debug menu here. And say [click] “start”. And now right away you can see that this output is true. Also, if you look at the safety CPU LEDs, you can see that the debug light is on, but also now the run light is on, meaning that the program is being executed.

So now we can test this and make sure everything is working.  But let's assume we've already done that and we're ready to deploy this program. Maybe this is a program that we deploy on every machine, so we are just ready to make it go and work so that the safety PLC will run this on its first cycle or whenever it powers up. So we have to go down here. And we can go to debug, but there's only stop, so we don't want to stop it. We can go to mode and there's only program; we don't want program mode. So that leaves safety validation. And what we'll do is validate the program. And we just say, yes, we're going to validate it. It's going to ask a few questions here. So now it says the safety CPU unit will start in the run mode on the next startup, and if I look at the LEDs on the front of the CPU, you'll see that the debug LED is still illuminated. So even though we validated it and finished that process, it's still in debug mode. So we could either cycle power right now, and it will power up in run mode, or will click on the run mode option here, and in the background I heard the relay turn off because it had been turned on in debug mode. That's the output relay from our function block here. And now I heard it go back on because the CPU went into run mode. And if we go back to the CPU with a little bit of “Blair Witch” type photography or vidography, you can see that the validation light is on and the run light is on, but the debug light, even though it looks like it's on, it's off. So we're in run mode and like I said in the very beginning with both of these set to true, it's basically going to reset this safety output every time this safety input is true.

OK, that's it for commissioning the Safety PLC and getting it into run mode. If you have questions you can contact us at the number or email above. Or reach out to us at, and we'd be happy to help.

If you have any questions or are just looking for some help, we're happy to discuss your application with you.  Reach out to us at (855) 737-4716 or fill out our online form.