panelview + objects

stu · Aug 13, 2009

hi i have a panelview + 700 which has a maintaned button which i would like to change to a latched button is there an easy way to change the instruction??
thanks stu

widelto · Aug 13, 2009

stu said:
hi i have a panelview + 700 which has a maintaned button which i would like to change to a latched button is there an easy way to change the instruction??
thanks stu

Write down your button´s connection and then instead of using a maintained button use a latched one, after changing button write back connection to the new button.
Depending on your application, you must use factorytalk view or rsview me, before doing so please make a backup up of your application just in case.

504bloke · Aug 13, 2009

stu said:
hi i have a panelview + 700 which has a maintaned button which i would like to change to a latched button is there an easy way to change the instruction??
thanks stu

What's the reason for doing this ?

stu · Aug 13, 2009

504bloke said:
What's the reason for doing this ?

i have changed the program that will need the button to unlatch.thanks stu

rdrast · Aug 14, 2009

stu said:
i have changed the program that will need the button to unlatch.thanks stu

Just in thought, you probably don't want an actual 'Latched' button, but rather an 'Indicator' button.

A 'Latched' button is not guaranteed (in my experience) to change it's state if it's corresponding tag in the PLC changes, especially if there are any other HMI's on the network.

Also, they have been known to get 'Stuck' in any event.

Generally, it's better to use a momentary 'Indicator' button, with two tags. One tag is the momentary action that gets sent to the PLC when it is depressed, which can be used or ignored in logic based on the system state, and the other tag is the 'Indicator' tag that will change the visible state of the object on the screen. That is on scan 100% of the time, and always responsive.

rta53 · Aug 14, 2009

I just had to deal with a similar issue in a PV+ 1000. I used a multistate button to set a bit in the processor. Basically it was acting as a toggle, press on, press off. That function worked fine. However in my program I had a condition that would reset the bit when needed. However the button on the panelview would not change. All I had to do was add the same bit to the indicator tag. Now the button changes to reflect the actual state of the bit.

504bloke · Aug 14, 2009

rdrast said:
Just in thought, you probably don't want an actual 'Latched' button, but rather an 'Indicator' button.

A 'Latched' button is not guaranteed (in my experience) to change it's state if it's corresponding tag in the PLC changes, especially if there are any other HMI's on the network.

Also, they have been known to get 'Stuck' in any event.

Generally, it's better to use a momentary 'Indicator' button, with two tags. One tag is the momentary action that gets sent to the PLC when it is depressed, which can be used or ignored in logic based on the system state, and the other tag is the 'Indicator' tag that will change the visible state of the object on the screen. That is on scan 100% of the time, and always responsive.

I agree, which is why i asked what the reason was for....

panelview + objects

stu

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504bloke

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stu

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rdrast

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rta53

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504bloke

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