Omron NX Safety Controller: Setting Up the IO

Hello this is Ray Marquiss, senior application engineer at Valin corporation. This video is going to show you how to set up the IO for the NX safety controller from Omron. If you've watched previous videos, you'll have a project that's at this point. You'll have a control PLC and you will have added the safety PLC and configured the network so you'll be able to tell that by clicking on the box there and pulling it down. We're going to look at the IO map in the control PLC just to see that there are IO points created for the safety controller, and you can see that we’ll click on the NX-SL part there, then the I/O that goes along with it so you can see that there are some IO points created.  If we create variables over here, which we can do by highlighting it and then saying create a data variable, or a device variable. Or we can go back in and manually do it. Type in for each one. We can create a variable for these.  There is going to be the variables for the safety controller and then there will be some variables for the I/O that goes along with that safety controller that’s mounted on the rack that you can see from our previous video. We'll come back to this in a minute.

It's better to set up the safety IO first, so we'll click over here and go to the safety IO. We want to look for the parameters for the input and output slices that we have, so we'll double click on that parameter and you can see a nice graphic that shows the slice and then over on the right is a tool box where we can pull down devices to connect to it. So I want to add a safety relay to this, so I'll just click on it and drag it over, get it close to one of those triangle points and then let go and you can see it even gives me a little bit of a wiring diagram here. And those correspond to the points on the slice itself physically. Typing in a comment here will allow you to describe what this is for, but this isn't the variable name.  We're going to do that in a little bit. So I'll type in a comment and you can have spaces and different characters in the comment name. And then I want to go do the inputs so I'll double click on the Inputs. And you'll see a similar graphic. And then the tool box I'm going to pull out because I haven't E-stop-you saw that in the configuration in the previous video. I can grab that E stop it so there's a single channel than a dual channel, so I'm I want to grab the dual channel and drag it and I can drag it to that first input point. But if I try to drag it to the second input point, it still uses the 1st and 2nd input points, so when you have dual channel devices they have to be put on the even numbered inputs or they have to start with the even numbered inputs. So once again I see sort of a simple wiring diagram here and I can add a comment. I only need to comment the first input point. And I want to grab…from the toolbox…I want to grab a reset switch, so I'll just click on that. It's a reset with the test output and I can put that anywhere. It doesn't have to be an even one like the dual channel devices do, but I just click on that or drag it to that triangle, let it go. And now I've got my normally open reset switch attached. I can put in a comment for that.

Once we're done here, we need to go look at the IO map. And will double click on the IO map. When you see these little triangles, you click on them and there's more information underneath that expands out. So when I dropped down for the safety output, you can see that my comment was there for that first output, but I want to add a variable so I can use it, so I'll just click in that field-and you have to actually click 3 times-and I'll type in a name. Once I've done that, I can drop down the info for the inputs. And once again, I'll click here. You click on that field 3 times and then you can type in a name, so we'll give it a name and then you can remember it. Notice what happens if I try to put a name in on the second input, because both of those are used by that same E stop switch and it knows that the; PLC software knows that, so it'll give me an error, so I have to delete that variable name. And I'll go down here to put in the one for the reset. You can see there's more than just the IO tags or variables that we need to create here, or that we can create here. There are other status and alarm IO points that could use variables, but you can look those up in the manual to see which ones you want to use or which ones you should have in your program.

But now we can go back to the control PLC IO map. This is control PLC. This is where we were before. Now that we know what the assignments are for the safety PLC inputs and Outputs, we can create variables over here in this control PLC. They don't have to be the same names. They can be completely different names, and what this will allow you to do is monitor the inputs and outputs of the safety PLC directly in the control PLC without having to write any code or communication code or anything like that. So I'm going back over here to the safety PLC to see what is my first logical input or first safety input. And I know that that's the eastop, so I'll go in here and just say that's the safety PLC's E-stop.  It could be any name you want. And then you can use those in your control PLC program. Notice that all of those are read only.  You can't write to the outputs. Or, of course, you couldn't write to the inputs. All of the variables here for the safety PLC IO are read only, so you can just monitor it.

Next, we're going to create some input and output variables that can be read and written by the control PLC. So if you look on the left over there where we've been clicking around for the regular safety IO. You'll see there's an entry called “Standard” and then underneath that is “exposed variables”. So we'll open the exposed variables and you can create an output variable or an input variable. And so I'll create one at the top there that says safety PLC to control PLC and make it a boolean. That's going to be an output variable, and then I'm going to create an input variable that's going to be the control PLC to the safety PLC. These names are meaningless, it’s just to kind of show you the direction that they're going, but then once I get done creating those, if I go back to the IO map for the control PLC by clicking on that tab and then go up here and look at the IO table for the NX safety controller, the NX-SL3300 there, you can see those two new variables that I just created are added in, and you can create a variable for those there and if you look at the attribute of those one is read only in one is write. So I can now add these variables to my program in the in the safety PLC and I'll be able to write to them from the control PLC. I can't use them as safety inputs on that PLC, but for standard input stuff like a simple reset or a selection of a zone maybe or something like that, I could use those standard inputs. And that will not take any special communications programming. It's just the create the program in both controllers correctly.

That's it for this video in a future video I'm going to show how to do some testing with your IO so you can make sure that you've wired your safety inputs and outputs correctly.

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.