You're right, there's another way. Actually with ACADE and most other ACAD-based products, there's usually a few dozen ways. And don't worry about how much you post. Very many of us on this forum were once right where you're at now. I was! It's all good, we'll get you together.
1. Enter AECOPYCIRCUIT at the command line, or go to Schematic> Edit Components>Copy Circuit. This command copies any circuit to another location in the same drawing. If you need to copy a circuit to a different drawing, use AECIRCCOPYCLIP, which is also found at Schematics>Circuit Clipboard>Copy Clip. This command will let you copy a circuit, any circuit, no matter how large or small, to another drawing. When pasting the circuit (using either command), ACADE will automatically update all tags. There are a few selections in the dialog for dealing with source arrows, fixed numbers, etc. You may want to review those options in HELP if they come into play for you.
2. As for I/O drawings, it's pretty common to see several drawings in a row that all have the exact same blocks in the exact same locations, with only field devices and buttons etc being different. However, if you're doing a 'Save As' and changing the drawing's name, you're making a lot of extra work for yourself. Also, if you're using Project Manager (which you should be, IMHO), then you'd have to manually add the drawing to the project. So here's what I would do, broken into several steps. This should help minimize the amount of go-back-and-edit that has to be done:
*Set up the I/O drawings, with only your ladders (or grid), bus wires if you need them...and rungs only if you must. Do this by entering ACENEWDRAWING at the command line, or go to Project Manager>New Drawing. This command makes the new drawing a part of the active project. I usually set up all of mine at once, the end result is a dozen or so empty drawings.
*Go to the first one and bring in your PLC modules. Don't add any wiring unless it's going to be on every drawing.
*Now, use the circuit clipboard to copy these two modules. Go through the next few drawings and paste it into each one. ACADE will retag for you, unless you made them fixed. (DO NOT use this command with fixed tags active. If you do, the software will consider each pasted component as a child and the original component as the parent. Trying to retag one will change the tags on the others. Un-fix any fixed tags BEFORE starting this command.)
Some notes:
--This command won't renumber wires; you'll have to do that part manually.
--When selecting the circuit to copy, make sure you capture all of the connection dots/tees. ACADE won't redraw those for you later if you miss them at first.
--It's to your benefit if you can have anything that will appear in the other drawings in your original circuit. So it's worth taking a beat to pause and think about what needs to be drawn later. This command copies everything about the circuit - even normal, non-attribute text. I often include notes and other things that aren't *technically* a part of the circuit. So if there's anything like that, be sure to have it in place when you start to copy.
--If you didn't know about it before, consider the command AEMULTI (Schematic>Insert Components>Multiple Insert). It's very useful when adding terminal blocks in a ladder drawing, or even a bunch of NO or NC contacts. It allows you to draw a single line across the rungs, and everything inserts along that line. So it all comes in already aligned, and you generally only have to input the catalog info once, and it's all done in one command. I use the crap out of that one.
Hope this helps,
Jim

Jim Seefeldt
Electrical Engineering Technician