type, the pulse-width type, one of these constants:
PS3000A_PW_TYPE_NONE: do not use the pulse width qualifier
PS3000A_PW_TYPE_LESS_THAN: pulse width less than lower
PS3000A_PW_TYPE_GREATER_THAN: pulse width greater than
lower
PS3000A_PW_TYPE_IN_RANGE: pulse width between lower
and upper
PS3000A_PW_TYPE_OUT_OF_RANGE: pulse width not between
lower and upper