How to /setblock a specific type of redstone (Debug mode)
Solution 1:
@ModDL gave a great answer, but sadly on my Minecraft 1.8, when I tried that using blockdata, it didn't do anything. I still appreciate his answer, although.
Check out the answers at How to place redstone using Command Blocks.
Even when I first examined it using F3 on my Minecraft in 1.8, it showed it like this:
north:none
south:none
etc.
I tried modification using /blockdata
but that didn't work.
So then I thought: Hmm... what about data values?
So then I tried /setblock (x) (y) (z) redstone_wire (0-15)
and then like a miracle, it worked!
It turns out Minecraft is showing what the damage value corresponds to.
In 1.8+ it interprets the damage value so that it's human-readable.
But in 1.7 and lower, it just shows (block name)/(damage value)
.