Burning State Question

Hi all,

My question is about an AOI and specific output bools. They're readable by anything external, HMIs, and so on:
- Sts_Active or
- Sts_Inactive or
- Both available

I think it's generally only necessary to have "Sts_Active" but I'm scraping to find that "gotcha" moment where it becomes necessary (or convenient) to have both.

A granular set of statuses might be Active (running), Inactive (not running, not faulted), Down (not running, faulted), but this may confuse the idea when dealing with an AOI that doesn't have a fault state.

Can I hear opinions either way?

Thanks and Happy New Year!

I suspect you are using Rockwell but check out this part of the CoDeSys help file that describes some common interfaces for Function Blocks (AOI's).

The concepts will apply to AOIs created in RSLogix as well as Function Blocks created in CoDeSys

https://help.codesys.com/webapp/behaviour_model;product=LibDevSummary;version=3.5.15.0

Looks like PlantPax. I don't see the need for both. For PLC code, you can negate to get the other state. In HMI, basically the same, but I guess it depends on what HMI you use.

As "ndzied1" mentioned, it appears that you are using Rockwell Software.
I usually make a "status" word (usually a DINT) and write a number into it depending on the result of the AOI. i.e. Motor Unknown Status = 0, Stopped = 1, Running = 2, Fault =3, or it can be expanded Running Forward = 21, Running reverse = 22, so 20<Status>29, then it's running regardless of direction. This can be expanded to add 100 to the status if the motor is in "Manual Mode". The same can be applied if you need to differentiate between faults. I find this method convenient if using different coloured symbols & text on the HMI or to display different alarms in the Alarm log.

I hope this helps