User`s guide

96 DC 900-1317J
ADCCP NRM Programmer’s Guide
4.3.2 ICP Station Reset Condition
If the client application receives an DLI_PROT_RECV_STATION_RESET packet, the client
application must send a
DLI_PROT_SEND_STATION_RESET_CFM packet to the ICP. The client
assumes that any unacknowledged data remains unacknowledged, and initiates higher
level data recovery procedures.
4.3.3 ICP Exception Conditions
Most of the exception conditions reported by the ICP are for information only. Specific
exception conditions are discussed in Section 3.4.25 on page 78.
4.4 Broadcast Procedures
The client application may use selective or global broadcast addressing to disseminate
normal data from the primary station to multiple secondary stations on an unbalanced
multi-drop configuration. In this case the ICP assumes responsibility for preparing the
targeted secondary stations to receive the broadcast. That is, the primary station resets
remote secondary stations if necessary to ensure correct alignment of sequence number
variables in all secondary stations for which the broadcast is intended. Once the send
and receive sequence number variables for all destination secondary stations are
aligned, the ICP proceeds with the broadcast.
The ICP does not report these station resets to the client application that initiates the
broadcast, because a reset notification would imply that the (as yet unacknowledged)
transmission is lost. On the other hand, the remote secondary station does report any
reset to its client application. If a station reset preceding the primary station’s broadcast
disturbs a secondary station’s data transmission, it is the secondary station’s responsi-
bility to initiate any required data recovery at a higher level.
During a selective or global broadcast, the ICP suppresses secondary station I-frame
responses by switching from normal polling procedures to RNR polling procedures.