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Use of event name when using hardware interrupt OB

Created by: Wim A. at: 12/29/2011 12:09 PM (3 Replies)

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12/29/2011 12:09 PM	Rate (0)
Wim A. Posts: 2 Rating: (0)	Hello, I am looking at understanding more about the interrupts in s7-1200. I am trying a hardware interrupt OB for the moment. I want to keep track of the number of boxes that go into a machine. For each box going in i have an edge that i can detect. So i setup the enable edge detection and call this event name : "box coming in". Then i assign this event to the interrupt "how many boxes are in the machine". The same thing happens for outgoing boxes. The event name :" box coming out". And assigned to interrupt "how many boxes are in the machine". When i go into the interrupt i want to see wich event caused the trigger so i can adapt the number accordingly. I try to use compare with event name buth i does not work.. How do i do this?
Wim A. Posts: 2 Rating: (0)
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12/29/2011 12:53 PM	Rate (0)
Gorp Posts: 89 Rating: (16)	I think you can notdetect which event caused the interrupt, so you have to make two separate interrupt OB's.
Gorp Posts: 89 Rating: (16)
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12/29/2011 1:08 PM	Rate (0)
0_Einstein Diamond Expert Joined: 7/7/2010 Last visit: 1/24/2025 Posts: 15558 Rating: (2468)	Wim A. Hello, I am looking at understanding more about the interrupts in s7-1200. I am trying a hardware interrupt OB for the moment. I want to keep track of the number of boxes that go into a machine. For each box going in i have an edge that i can detect. So i setup the enable edge detection and call this event name : "box coming in". Then i assign this event to the interrupt "how many boxes are in the machine". The same thing happens for outgoing boxes. The event name :" box coming out". And assigned to interrupt "how many boxes are in the machine". When i go into the interrupt i want to see wich event caused the trigger so i can adapt the number accordingly. I try to use compare with event name buth i does not work.. How do i do this? I do this on many of my applications to detect which event happened first and lock onto that input and process accordingly. Use the edge detection for your two inputs by creating your interrupt OB first, then point to that OB in the PLC input configuration screen. Those inputs must be wired into the PLC inputs and not an add-on signal module inputs. Inside your interrupt OB, there is only one edge to detect that causes the OB to run for a single scan, so look for that input state to be whatever you want, and cause it to increment a counter or set a bit you can handle in your main OB. Boxes move more slowly than 10-20ms you would get for your main OB's processing time, so you could really just use -\|p\|- to incrementcounters for boxes-in and boxes-out. You might want to add a debounce timer in case the boxes skew slightly during entry and exit.
	science guy
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12/30/2011 1:20 PM	Rate (0)
Wim A. Posts: 2 Rating: (0)	Thanks, I should have tought of that. It is indeed the logic thing to do. Many thanks.
Wim A. Posts: 2 Rating: (0)
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