The output register in the aos has the following functions connected:
Bit	hex	Function

1	00001	AOS_1 Noise source   ON  (Set bit and reset after delay)
2	00002	AOS_1 Noise source   OFF (Set bit and reset after delay)

3	00004	AOS_1 Comb           ON  (Set bit and reset after delay)
4	00008	AOS_1 Comb           OFF (Set bit and reset after delay)

5	00010	AOS_1 IF                 (Set bit and reset after delay)
6	00020	AOS_1 50 Ohm             (Set bit and reset after delay)

7	00040	AOS_1 1db	     On=set, Off=reset
8	00080	AOS_1 2db	     On=set, Off=reset
9	00100	AOS_1 4db	     On=set, Off=reset
10	00200	AOS_1 4db 	     On=set, Off=reset	( Total 11 db)

11	00400	AOS_2 Noise source   ON  (Set bit and reset after delay)
12	00800	AOS_2 Noise source   OFF (Set bit and reset after delay)

13	01000	AOS_2 Comb           ON  (Set bit and reset after delay)
14	02000	AOS_2 Comb           OFF (Set bit and reset after delay)

15	04000	AOS_2 IF                 (Set bit and reset after delay)
16	08000	AOS_2 50 Ohm             (Set bit and reset after delay)

17	10000	AOS_2 1db	    On=set, Off=reset
18	20000	AOS_2 2db	    On=set, Off=reset
19	40000	AOS_2 4db	    On=set, Off=reset
20	80000	AOS_2 4db 	    On=set, Off=reset   ( Total 11 db)