Is there an easy way to get an "Always On" tag in Logix5000?

JaxGTO,
i'm not a logix 5000 expert. what happens when someone uses 20 or 30 of this always on bits to debug the program and get it running. he forgets / doesn't correct the logic because it's 2 am. then a year later, Bubba modifies the program on the weekend during a maintenance day without telling anyone he turned off the bit or does it by accident. Monday morning, the machine doesn't run and everyone is in a state of panic?
this is why we put the always on / off rung as the first line of the plc code.
james
 
The only problem with that is when Bubba'a online and he toggles the TRUE bit off it will stay off. Always make sure on the first rung to turn it back on. And force the status of the AFI bit off.


When it is set to constant, it cannot be toggled from a rung in the ladder window. However it can be changed from the tag database
 
The only problem with that is when Bubba'a online and he toggles the TRUE bit off it will stay off. Always make sure on the first rung to turn it back on. And force the status of the AFI bit off.

if it’s ever changed, major fault the controller. if an “always true” expression isn’t always so, then the PLC shouldn’t also be in an undefined state.
 
When it is set to constant, it cannot be toggled from a rung in the ladder window. However it can be changed from the tag database

How?
Open tag properties, untick constant (only offline mode?), Hit ok, toggle bit, download? Or is there another way?

Seems as difficult as inserting a rung with "otu always_on" halfway through the code.

For both, don't let your cats play with your code.
 
How?
Open tag properties, untick constant (only offline mode?), Hit ok, toggle bit, download? Or is there another way?

Seems as difficult as inserting a rung with "otu always_on" halfway through the code.

For both, don't let your cats play with your code.


I understand your point, someone can always work around it. My point was more to show that a bit that is set to constant can simply be set to 1 from controller tags.


You don't need to download to change the constant property, right click, edit properties, uncheck. Although at that point, Bubba's gonna do what Bubba's gonna do, so I'm with you there.
 
Although at that point, Bubba's gonna do what Bubba's gonna do, so I'm with you there.

I have thought further on this. Perhaps we are misnaming the "always_on" bit. "Please_leave_on"? "I_put_games_in_Routine_14_please_play_around_there"? "I_dare_you_to_leave_me_on"?

Curiously, does "XIC TRUE" work? or "XIC 1"?
 
I have thought further on this. Perhaps we are misnaming the "always_on" bit. "Please_leave_on"? "I_put_games_in_Routine_14_please_play_around_there"? "I_dare_you_to_leave_me_on"?

Curiously, does "XIC TRUE" work? or "XIC 1"?


XIC 1 will not work, XIC TRUE will work if there is a tag named TRUE. It's not a built in constant or anything like that, although that would be neat.
 
I have thought further on this. Perhaps we are misnaming the "always_on" bit. "Please_leave_on"? "I_put_games_in_Routine_14_please_play_around_there"? "I_dare_you_to_leave_me_on"?

Curiously, does "XIC TRUE" work? or "XIC 1"?

'Bubba_P**s_Off' is probably best.
 
If you are using this as an input parameter to an AOI, which it sounds like you are doing (from post #4), then you don't need a tag, just put literal "1" where you would put the always-on tag for the AOI instances that need the parameter to be ON, and "0" for instances where you need it OFF.

2019-12-13_111103.jpg
 
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