Modify tag for alias issue

[suboliu]

Hello everybody,
Today I read some Rslogix 5000 program code, but I want to modify a tag which is a alias tag to another alias. that is change this tag for another alias, but, tag edit window show that the alias field is gray, so can't change. I test and create another tag BB to same alias. after verified, I open BB tag edit window, It showed me that may modify and change, but why original can't modify and change.
see attach file.

Thanks

 

[rdrast]

You can only modify a tag online that is NOT IN USE.

 

[suboliu]

You can only modify a tag online that is NOT IN USE.

I am not online, I am offline, why I can't modify it?

 

[A_G]

I think you have a Safety PLC, (1756-L71S), if I remember correctly you may have to "unlock" the safety PLC before you can edit the tag

 

[suboliu]

I think you have a Safety PLC, (1756-L71S), if I remember correctly you may have to "unlock" the safety PLC before you can edit the tag

It is safety PLC, but it is unlocked. my question is why I can add a tag for input alias, but can't modify a tag for input alias.

 

[rdrast]

Because the first one is only a sort of alias. You have actually named it right down the the physical IO word (or autogenerated an alias). The second, you actually gave a name to.

The first one has special characters not allowed in names normally.

 

[suboliu]

Because the first one is only a sort of alias. You have actually named it right down the the physical IO word (or autogenerated an alias). The second, you actually gave a name to.

The first one has special characters not allowed in names normally.

hello
you mean that "Main_Panel_Point_IO:5:I" is special characters and auto generated? that is when add module, It will generate this word ? so can't modify? can explain more detail?
thanks

 

[suboliu]

Because the first one is only a sort of alias. You have actually named it right down the the physical IO word (or autogenerated an alias). The second, you actually gave a name to.

The first one has special characters not allowed in names normally.

when add module, It auto generates tag Main_Panel_Point_IO:I.Date and not Main_Panel_Point_IO:5:I, Main_Panel_Point_IO:5:I tag should be programmer create tag to alias to input tag Main_Panel_Point_IO:I.Date