Verilink ConnecT 56K DSU (896-502110-001) Product Manual - Manual (Page 26)

Installation
2-10 ConnecT 56K DSU User Manual
[F][A][C][V.25 bis COMMAND][FCS][F]
The address field [A] is FFH. The control field [C] is set to 13H except
for cases of multi-frame responses. For this case, the control field is set to
03H in all but the last frame. The 03H in the control field indicates that
other frames are to follow while the 13H in the control field indicates the
final frame.
BI-Sync option character format
1. Data bits - 7
2. Parity bit - OD
COMMAND STRUCTURE:
[SYN][SYN][STX][V.25 bis COMMAND][ETX]
Asynchronous option character format
1. Start bit - 1
2. Data bits - 7
3. Parity bit - EVEN
4. Stop bit - 1
COMMAND STRUCTURE:
[V.25 bis COMMAND][CR][LF]