User`s guide

216 DC 900-1340I
BSC Programmer’s Guide
B.1.4 Data Reception
The BSC 2780/3780 software can receive data at any time after the link is started. The
client application program should have a
dlRead request issued at all times so the
received data can be transferred to the client. Figure B–6 is an example of how the
BSC 2780/3780 software receives a typical data message.
Figure B–6: Data Reception Sequence
Client Freeway
Remote Station
608 Bytes Normal Data
ENQ
ACK0
EOT
Block 1 (ETB)
254 bytes data
Block 2 (ETB)
254 bytes data
ACK1
ACK0
Block 3 (ETX)
100 bytes data
ACK1
dlRead
(
DLI_PROT_SEND_NORM_DATA_EOM)