RS Logix 5000 / ControlLogix - Can you create a new Analog Tag online ?

Good Afternoon,

I should know the answer to this . I have a 1756- 4-20 ma input card with spare inputs .I would like to add a new Analog Input tag . I can do that online , and also , scale it , correct ?

Thanks so much for your help,

if the module is already installed - and working - then you probably already have a tag available for each of the module's channels ... you should also be able to scale each of the channels ... try doing a Right-Click on the module in RSLogix - and take a look at the Properties tabs ...

you can make an ALIAS (street name) for any existing channel ... is that what you're asking? ... if so, then yes that can be done online ...

You can add new Controller Tags to the database, just makesure that you set the type as they default to DINT usually. You can also Add logic at runtime and even call a add on instruction. The only thing you cannot do is modify the code or tags within an addon structure.

But word of Warning "I would be very careful in changing an Online system as events could be un predicatable and you could damage something or Kill someone. Best practice is always to make changes in a controlled "offline" enviroment and TEST, TEST, TEST!"

Especially because of the nature of the orginal question I would wary of competance to modify or add on the "fly".

And to add to the tag information above, you CAN create a tag online, but you cannot modify the tag type once it has been created.

If you create a new tag and mistakenly accept the default DINT type, you cannot come back and change it later to a REAL. If you created it as an alias to one tag but needed to change that, you cannot do so. But, if an item is not being used, you could delete it and then recreate it.

You can of course change any of those by going offline.

OG