The version number is written on a small sticker, which is on the side of each P-mag. Check there for your version number. I doubt you are at version 40 because that came out in late summer of 2014.
This version fixes a very odd lost timing issue that only a very few of their customers experienced. This only happened on the ground, during startup, and would have been caught during the pre-flight check.
The other change was to fire the plugs 4* PAST TDC during the starting cycle. This helps with starting when a lightweight prop is installed and allows you to set the timing mark at TDC.
Wiring for a serial connection is easy. I often recommend builders run all the wires into the cockpit, just in case they need to use the EICAD program or think they might install an EICommander later on.
See the P-mag manual on how to wire for the serial connection. If you bring all the wires into the cockpit, bring in a tach line as well, just in case you elect to install an EICommander. If you think you will never install one, there is no need to run the tach signal line.
For the ground, we found it best to bring the ground line in from the P-mag and not use a ground off the ship's main ground bus.
Once you bring up the EICAD program, you can set the timing and advance limit. Read the manual and make sure you understand it. Basically, the timing starts at 26*, so you want to put in a negative offset to get it down where you need. The P-mag works in increments of 1.4* so you probably want to enter a negative 5.6, which will bring your timing down to 20.4* BTDC. Check your engine manual to make sure that is the timing you should have! Then set the max advance, start conservative as you can always change it later. For new engines, I recommend setting the advance limit to the desired initial timing so it works like a standard mag. Once the engine is broken in, then you can change it and let it advance. (The other option is to plug the vacuum lines and stay low during engine brake in.)
Once adjust the P-mag with the EICAD program, leave the jumper off. All software changes to the P-mag are made to the "B" configuration, thus you don't want to force it to the "A" configuration by putting the jumper in.
Good luck!