@cmac, I tried waking up my PC from my mac, and I came up with these tips for sending the wakeonlan "magic packet" from a TRIGGERcmd command on a mac:
First, make sure you've enabled Wake on LAN in the PC's BIOS, like so:
Get your PC's network interface's mac address. Google how to do that if you don't know. Also, it has to be a wired connection, not wireless. You probably already knew that, but just in case.
On the mac, do the brew install wakeonlan command to get it installed, then open a terminal and try it using a command like this:
… where c0:7c:d1:a1:89:f8 is the PC nic mac address.
If that works, you're golden. The next thing is, in the TRIGGERcmd command on the mac, you have to specify the full path to the wakeonlan binary. Brew installs in as /usr/local/bin/wakeonlan.
So you command field should look like this:
YMMV. In my case, I couldn't turn my computer on if it was off. I could only wake my PC up from sleep mode.