Fairfield doesn't use tone outs in the QCII sense which is what the 996/396 work off or. They use the standard centracom alert tones off the board. the long steady tone may work for fto it should be 1000htz, the alternating (ALERT III) can not be decoded. What you need to do is listen to the tone and see if there is a standard length of tone duration. If they consistently sound the tone for less than 5 sec try option 1 below if the tone is sounded for 5 sec try option 2 below. If it varies it means the dispatcher just pushes the alert button and you will not have a consistent decode of the tone due to its various lengths. As a last resort you can put them both in and see which one picks up more.
option 1
tone A: 1000.0 ht z
tone B: 0.0
option 2
tone A: 0.0
tone B: 1000.0 ht z