CompactLogix Future Add of Point I/o

Good evening,

I have a point i/o project that the customer knows they want to add an additional unit in the year or so when funds are available.

Question, could I have this future AENT setup in my configuration w/o any issue when it will not be present?

If so second question, is anyone aware of a system tag I could use to toggle visibility in my OIT program while this future portion is not present?

Unfortunately I do not have an AENT available to see for myself.

v29, L30ER if that makes any difference.

Edit: Thinking back on an old project I do not remember any issues with offline AENTs as long as major fault was disabled...So might have that answer. Suppose I just need to find away to toggle the OIT portion when it is offline.

It's certainly possible, and yes, as long as you disable the major fault on connection failure for the AENT and all attached modules, you should be fine. I believe that option is disabled by default in v29 so you should have no issues. Just set up a tag in your PLC which, when set, will hide all the applicable items on the HMI. Then just give them a (password protected) pushbutton which will turn that bit back off when they install the new equipment.

You could, if you wanted, inhibit the connection to the AENT entirely using that same bit, so that you don't have any I/O errors in the meantime. See this thread for details.

The only other thing I'd be considering here is that if you allow the system to run just fine without that AENT chassis present, you should also consider what might happen later on if it is supposed to be present and isn't. In some cases it won't present an issue - e.g. if all the equipment connected to that rack is standalone and doesn't relate to any other equipment, then no problem. But if your main piece of equipment is relying on signals from that I/O rack to e.g. feed material downstream into the remote system, then you might need to have some means of checking the status of that rack to make sure the information you're getting is valid.

If you are talking about 1734 point I/O then you can add these Off-Line only.

Thanks for the feedback! Got this setup to inhibit the modules and really like it.