Today I decided to switch positions of my 127-128, to take advantage of the chirp / down view on the 128 with the CP 100 transducer. I sure was surprised, when I removed both units to switch them and the the sockets on the two MFDs were different. So much for Chirp up front.
NATCH,
There should be no need to swap the MFDs. Should these MFDs be interfaced to one another via an appropriate length of RayNet (F) to RayNet (F) Cable, or should the MFDs and CP200 be interfaced to a HS5 Network Switch, then you should be able to view 50 kHz conical sonar, 200 kHz conical sonar, CHIRP (conical) sonar, DownVision sonar, and SideVision on either of the networked MFDs. Naturally, both of the MFDs and CP200 would need to be powered ON. After interfacing the MFDs and CP200 in this manner, then you need simply select the desired sonar source to be viewed within the Fishfinder application of the MFD being viewed.