AEA PK-232 Technical Reference Manual page 51

PK-232 TECHNICAL MANUAL
The frame shown is an I frame, not going through a level 2 repeater, from WB4JFI (SSID=0) to
K8MMO (SSID=0), with no level 3 protocol. The P/F bit is set; the receive sequence number (N(R))
is 1; the send sequence number (N(S)) is 7.
A.2.13.1.1 Destination Subfield Encoding
Fig. 3 shows how an amateur call sign is placed in the destination address subfield, occupying oc-
tets A1 thru A7.
Where:
1. The top octet (A1) is the first octet sent, with bit 0 of each octet being the first bit sent, and
bit 7 being the last bit sent.
2. The first (low-order or bit 0) bit of each octet is the HDLC address extension bit, which is set to
zero on all but the last octet in the address field, where it is set to one.
3. The bits marked "r" are reserved bits. They may be used in an agreed-upon manner in individ-
ual networks. When not implemented, they should be set to one.
PK232TM Rev. A 5/87
Fig. 3A – Nonrepeater AX.25 frame
Octet ASCII Bin. Data
01111110
Flag
A1 K 10010110
A2 8 01110000
A3 M 10011010
A4 M 10011010
A5 O 10011110
A6 space 01000000
11100000
A7 SSID
A8 W 10101110
10000100
A9 B
A10 4 01100100
A11 J 10010100
A12 F 10001100
A13 I 10010010
A14 SSID 01100001
Control I 00111110
PID none 11110000
FCS part 1 xxxxxxxx
xxxxxxxx
FCS part 2
Flag 01111110
76543210
Bit position
Fig. 3 – Destination Field Encoding
Octet ASCII Bin. Data
A1 W 10101110
A2 B 10000100
A3 4 01101000
A4 J 10010100
10001100
A5 F
A6 I 10010010
CRRSSID0
A7 SSID
Bit Position 76543210
APPENDIX A – AX.25 LEVEL 2 PROTOCOL
Hex Data
7E
96
70
9A
9A
9E
40
E0
AE
84
68
94
8C
92
61
3E
F0
HH
HH
7E
Hex Data
AE
84
68
94
8C
92
A-6 Page 51