IFR 2026

INSTALLATION
2-8 46882/439
FSK operation
Data for FSK operation is carried on the contacts of the AUXILIARY PORT as shown by
Table 2-1 below. The unused contacts are left unconnected.
Table 2-1 Auxiliary port contact assignments
CONTACT FUNCTION
14
Source A − FSK A
15
Source A − FSK B
16
Source B − FSK A
17
Source B − FSK B
18
Source C − FSK A
19
Source C − FSK B
12 0 V
The frequency shifts produced by the applied data are as shown in Table 2-2 below for 2FSK and
in Table 2-3 below for 4FSK.
Table 2-2 Auxiliary port inputs for 2FSK
FSK A FSK B
SOURCE A pin 14 pin 15
SOURCE B pin 16 pin 17 SHIFT
SOURCE C pin 18 pin 19
LOGIC LEVELS 1 *0 +D
0 *0
−D
where D is the set deviation value.
*Tie FSK B as 0 or leave floating.
Table 2-3 Auxiliary port inputs for 4FSK
FSK A FSK B
SOURCE A pin 14 pin 15
SOURCE B pin 16 pin 17 SHIFT
SOURCE C pin 18 pin 19
1 0 +D
LOGIC LEVELS 1 1 +D/3
0 1
−D/3
0 0
−D
where D is the set deviation value.