I don't have this switcher (but I am thinking about buying one) but looking at the documentation it seems there is a command (or "order" as in "I order you to...") protocol and a status protocol. The commands are 4 bytes long. The first is the command, the second is the command inverted (~order) and the last two appear to be markers of some sort. So it appears that the power toggle command is the string:

"\x10\xEF\xD5\x7B";

I would expect that the switcher would reply with a status string that your would then need to decode. Annoyingly there doesn't appear to be discrete power codes but I suppose you could try sending a dummy command like:

"\xFF\x00\xD5\x7B";

and see if the switch responds with status. If so you can determine the power state from the status returned and decide whether the switch needs to be powered on. You could also leave it on all the time I suppose.

The switching commands are fairly simple:

A = 1 "\x00\xFF\xD5\x7B";
A = 2 "\x01\xFE\xD5\x7B";
A = 3 "\x02\xFD\xD5\x7B";
A = 4 "\x03\xFC\xD5\x7B";
B = 1 "\x04\xFB\xD5\x7B";
B = 2 "\x05\xFA\xD5\x7B";
B = 3 "\x06\xF9\xD5\x7B";
B = 4 "\x07\xF8\xD5\x7B";

Again. I have no way of testing this but this is how I interpret the docs. Please let me know if this works.