Angelo1 Posted July 31, 2009 Report Share Posted July 31, 2009 Hi All, I built a middle complex application, which controls a machine. (Motors, Vibrators, etc.) In case of emergency, I created a software emergency stop to handle motor stop and stopping my application. Now I am wondering what is the best way to integrate my emergency stop button in the main applications front panel? In case the application freezes (yes, I am still debugging some problems due to timing), I don't want the button to not react any more. I tried to do it with a subpanel until I found out, that even if the VI of the button runs, the subpanel won't react any more. Then I tried to to run the Stop-VI separate and bring the Stop Button in front of the main application(like a dialog). However then I can't use the main application... I think you see what is my problem. I can control the stop in a separate VI fine, even in case of malfunction of the main application. But how can I now put both VIs on one screen? Any suggestions or ideas? Thanks, -Angelo Quote Link to comment
unicorn Posted July 31, 2009 Report Share Posted July 31, 2009 ..Then I tried to to run the Stop-VI separate and bring the Stop Button in front of the main application(like a dialog). However then I can't use the main application... What is about using VI server? The VI with the Stop button is running as a separate application and not as a dialog window. It opens a VI-reference to the VI to be controlled and if the stop button is hit the method "Abort VI" (using Invoke Node with the VI reference) is called. Quote Link to comment
Angelo1 Posted July 31, 2009 Author Report Share Posted July 31, 2009 What is about using VI server? The VI with the Stop button is running as a separate application and not as a dialog window. It opens a VI-reference to the VI to be controlled and if the stop button is hit the method "Abort VI" (using Invoke Node with the VI reference) is called. Yes, you are right. This is the way that I tried and liked. The problem I am having is, that I need to see and use the stop button any time. The Main application FP is maximized. So the stop button will be hidden behind it. I tried to use the Stop button VI as "frontmost", but then I can not control the main application anymore. Any idea? -Angelo Quote Link to comment
ESST Posted July 31, 2009 Report Share Posted July 31, 2009 If this is an Emergency Stop Button, shouldn’t it be implemented purely in HW? What if your UI computer goes down? When you have a motor, I'm guessing you will need emergency stop buttons at the motor itself and by the work station, at least. 1 Quote Link to comment
Angelo1 Posted July 31, 2009 Author Report Share Posted July 31, 2009 (edited) If this is an Emergency Stop Button, shouldn’t it be implemented purely in HW? What if your UI computer goes down? When you have a motor, I'm guessing you will need emergency stop buttons at the motor itself and by the work station, at least. ;-) You are absolutely right. When I was googleing for a solution I found the same statement. I totally agree. Still I want to keep that button, because I know the users... I am considering calling it immediate stop. A HW switch is needed indeed. Thank you for the good hint. In case of emergency, this is not the thing I want to help me. ;-) I am thinking of resizing my main application a little bit smaller and just have the window with the button next to it... Is there another better solution? -Angelo Edited July 31, 2009 by Angelo1 Quote Link to comment
unicorn Posted July 31, 2009 Report Share Posted July 31, 2009 It is true what ESST says. If you need to reduce the risk then a big emergency button near the computer is the solution which should be implemented first. Regarding a floating window: make the window floating and not modal. (VI Properties > Category "Window Appearance > Customize... > check floating under Window Behavior) Quote Link to comment
crelf Posted July 31, 2009 Report Share Posted July 31, 2009 If this is an Emergency Stop Button, shouldn’t it be implemented purely in HW? Right - when it's an emergency (hence the name) you need it in hardware, not software. Still I want to keep that button, because I know the users... I am considering calling it immediate stop. I wouldn't call it "immediate stop", because that suggests it's the same as an emergency stop. Also, it gives the operator 2 options, so if there's an emergency, they need to think and make a decision on which button to press (SW or HW), and decision making is difficult and unreliable under emergency situations. Stick with having a HW stop, and monitor it with a digital input so your software can react appropriately. 1 Quote Link to comment
Angelo1 Posted July 31, 2009 Author Report Share Posted July 31, 2009 I wouldn't call it "immediate stop", because that suggests it's the same as an emergency stop. Also, it gives the operator 2 options, so if there's an emergency, they need to think and make a decision on which button to press (SW or HW), and decision making is difficult and unreliable under emergency situations. Stick with having a HW stop, and monitor it with a digital input so your software can react appropriately. Finally I am convinced to let that button completely away. I never thought about the decision making between HW and SW if both is available. Thank you all! -Angelo Quote Link to comment
crelf Posted July 31, 2009 Report Share Posted July 31, 2009 Finally I am convinced to let that button completely away. I never thought about the decision making between HW and SW if both is available. Thank you all! No worries - that's what we're all here for - to learn for each other Quote Link to comment
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