command in the low order word and a channel number in lowest
four bits of the high order word.
The Switch command values are:
Clear(0)
Clears all of the switch commands listed below for the specified
channel.
Lockout of Protection(1)
Prevents any of the working channels from switching to the protection
line.
Forced Switch of Working (to Protection)(2)
Switches the specified working channel to the protection line.
Forced Switch of Protection (to Working)(3)
Switches the working channel back from the protection line to
the working line.
Manual Switch of Working (to Protection)(4)
Switches the specified working channel to the protection line.
Manual Switch of Protection (to Working)(5)
Switches the working channel back from the protection line to
the working line.
Exercise(6)
Exercises the protocol for a protection switch of the specified
channel by issuing an Exercise request for that channel and
checking the response on the APS channel.