I have an HDS Carbon with active imaging 3 in 1 on the bow, along with Active Target on the trolling motor too. Has anyone noticed a difference with all this “pinging” going on? I can manually shut off sonar pinging, and manually shut off structure pinging, but I never have. Does running multiple pings from essentially 4 different transducers effect the picture quality? It has to, right?

So. Now the real question....how do I turn off the Active Target transducer when I only want down scan, or only want 2D sonar? That Active Target transducer is pinging, even when I shut off the front graph completely!! I have to turn off both the bow and console graphs in order to power down the Ethernet line and Active Target “box”.

Am I doing something wrong?

The frequency on the AT is far from the frequency of sonar and SS so no interference or cross talk should happen. You can turn on stop sonar, also in SS Is their a stop sonar on AT? Don't have mine yet so don't know. Seems like I read somewhere you can. You can go to advance settings and turn it off in the unit which is a long way to go but if you have to turn it off that will do it.

Update there is a stop sonar on AT.

Yes, you are doing something wrong. Your installation is not ideal, but it can be easily fixed. The fix has an additional advantage also - you have the opportunity to save power.

Note that Active Target is an accessory that can be turned on or off at will. It doesn't require a procedural shutdown like your HDS Carbon prefers.
The key is that so-often-misunderstood yellow wire in the power cables. It sounds like your trigger wire (yellow) is attached between the two displays, and there is no reason I can see that you need to have it that way, but this is easily corrected.
Connect the yellow "trigger" wire on the BOW Carbon power cable to the yellow wire on the Active Target power cable. Nothing else in the circuit, and certainly not 12V. With that configuration, the Active Target control box will turn on and off as you turn the bow HDS Carbon on or off. This will save some small amount of power. If you sleep the bow Carbon, or turn it off, the Active Target will turn off as well. It will turn back on when you wake up the bow Carbon. The trigger wire is an output from the HDS units; the yellow wire on the console Carbon can remain unconnected. Only the bow Carbon yellow wire would be connected to the AT.

Now for the extra trick that gives you some versatility, control, and saves power. Let's assume there are times you will have the bow Carbon on, but really do not need or want Active Target. No need to have it running then, right? You don't want power to be wasted needlessly, and maybe it's better not to be pinging so much electronic "noise" into the water (even if it does not affect image quality). How to do that? Very simple! Add a simple SPST switch in series in the yellow "trigger wire" connection described above. If you turn that switch on, the two yellow wires are connected, and the AT will power up and down as a slave to the Carbon. If that switch is turned to "OFF" (open circuit) the two yellow wires are not connected. The AT black box will NOT power up without the trigger signal from the Carbon. In both cases I describe, the POWER pin of the AT can be tied to a constant fused 12V. There is no need for power to that box to be switched. The box will ONLY draw power if the trigger circuit is completed.

So, any time you don't want or need AT, just flip that toggle switch to "OFF" and the entire AT will shut down, pinging and all, saving you power. You can locate this switch at the bow panel for convenience. Decide you want to take a look around with AT? Flip that switch and it will be operating in a jiffy.

Thanks buddy! You always have a logical fix. I’m gonna do that.

Glad to be of assistance. One thing I realize I wasn't clear about is my ending comment on use of the switch. I'd like to clarify that it only has an effect when the bow Carbon is operating. (This is OK since you wouldn't really need the AT to power up unless that bow MFD was on anyway.)

Great suggestion!

News flash!

Once activated via the yellow wire, either through a graph or a switch, the unit doesn’t turn off. The only way to currently remove power is with a switch on the red “b+” wire.

Lowrance is aware of the issue and promises to correct it on a future software update!

I'm glad you figured out this issue existed. That way, by the time I get an Active Target installed, I have a chance the update will be out!