Technical data

Byte Field to be sent (request) Byte Field received
(Confirmation/Indication)
0 com_class
FDL request=00
(service request to layer 2)
0com_class
FDL confirmation = 01H
(acknowledgment from layer 2
firmware after FDL request) or
FDL Indication = 02H (data
received)
1user_id
Freely assigned ID that is
returned unchanged in the
confirmation
1user_id
Identifier assigned in an FDL
request (only relevant for
confirmation; with indication the
value is "0")
2 service_code
Type of requested service:
SDA = 00
H
SDN = 01
H
SRD = 02
H
RPL_UPD_S = 06
H
RPL_UPD_M = 07
H
2 service_code
Type of service provided by the
layer 2 firmware
SDA = 00
H
/ SDN = 01
H
SRD = 32
H
Only with FDL confirmation:
RPL_UPD_S = 06
H
RPL_UPD_M = 07
H
Only with FDL indication:
SDN_MULTICAST = 7F
H
3 link_status
only relevant for confirmation
relevant
3 link_status
(see table 17.11)
4 service_class (priority)
Low = 0
H
, High = 1
H
4 service_class (priority)
Low = 0
H
, High = 1
H
5 DSAP/RSAP
Number of the destination SAP
(default SAP = FF
H
)
5 DSAP/RSAP
Number of the remote SAP
(=Source-SAP) (default SAP =
FF
H
)
6 rem_add_station
station address of the receiving
station
6 rem_add_station
station address of the receiving
station
7 rem_add_segment
logical segment address; always
enter FF
H
7 rem_add_segment
logical segment address; always
enter FF
H
Table 17.10 Structure of the Confirmation/Indication/Request Header
Appendix B8976060/02
Volume 1 17 - 22