Learn how to configure alarms with dynamic setpoints.

Video recorded using: Ignition 7.7


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[00:00] It is possible to have dynamic setpoints on alarms in Ignition. That way, operators can change a high or low setpoint, that changes how the alarm is being evaluated. So, here for example, I have a tank level. And I want to alarm the tank level when it goes below 10 and above 90. So, if I right click and go edit the tag, and put the alarm on here, put a new alarm, and I set the mode to, say below setpoint, put a value of 10, I'm actually hard coding that value here. So, rather than hard coding, as you can see, all the properties of the alarm condition here, all the settings, have a little database icon to the right hand side. And that allows us to actually link that setting to either a tag, another tag in the system, or an expression, which is a calculation. So, rather than having a hard coded value, we can actually link it to another tag. So for this, I'm going to cancel this for a second. For my tank level, I want to have a low setpoint and I want to have a high setpoint, as separate tags. So, if they don't exist in the PLC, we can right click on our tags folder and I can add a couple of memory tags. I'm going to add a memory tag here. The first one, I'm going to call it low setpoint, and I'll make it integer. And I'll put the value here as default of 10. I'm also going to create another one called the high setpoint. And I'll put the value, again it's integer, the value as 90. So, now I have my two high and low setpoints. They're coming from tags. I'm going to right click on the tank level again, go edit the alarm. I'm going to add two alarm states. The first one being our low alarm. I'm going to set the display path to Tank A, and you can set the notes and all that, but down here under the alarm mode settings, I'm going to set the mode to be below setpoint. And rather than put a value in here, I'm going to bind that setpoint to another tag. In this case, I'm going to use the Low SP memory tag we just created. I'm going to do the exact same thing for my high state. I'm going to go and set this one up to high, my display path again, Tank A, come down here to the mode and set this to be above setpoint, and bind the setpoint to another tag. I'm going to set that to the high setpoint. So, it's very easy for us to bind any of these properties of the alarm to another tag or to expression, thus making that dynamic. So, as soon as I press okay, I'll see if this... That little bell on the right hand side of the tag, and I can see, if I expand it, if it's currently active. So, right now, it's not because it's not in that state. Of course, if the value was to go, let's say, below 10, like, if I put the value to a value of 8, you're going to see it's active now. But if I go up here and set the Low SP to say, a value of 5, so the operator was to change that value, now you'll see the alarm is no longer active because it's using this setting for the low and the high setpoints.

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