User`s guide

60 DC 900-1317J
ADCCP NRM Programmer’s Guide
stations unless the client has enabled ADCCP option 8 for the specified secondary sta-
tion. The client must specify
the usProtCommand field (DLI_PROT_SEND_NORM_DATA), the
iProtModifier field, the usProtXParms[0] field (station ID), the usProtXParms[1] field (data
size), and the data field contents.
For NRM primary and secondary stations, bit 0 in the iProtModifier field indicates
whether more data follows. The client should use the more data indication if one of the
following conditions applies:
• The client sends numerous DLI_PROT_SEND_NORM_DATA packets via an NRM pri-
mary station using selective or global broadcast addressing and wants to use RNR
polling instead of RR polling to inhibit secondary response I-frame transmissions
during the broadcast
• The client wants to send as much data as possible in each poll response via an
NRM secondary station.
When bit 0 in the iProtModifier field is reset to zero, the ICP assumes that the data packet
is the final frame in a data set. If the data packet is sent via an NRM primary station, the
ICP enables normal polling. If the data packet is sent via an NRM secondary station, the
ICP transmits the data in an I-frame with the F-bit set to one.
When bit 0 in the iProtModifier field is set to one, the ICP assumes that more data pack-
ets follow. If the data packet is sent as part of an NRM primary station broadcast, the
ICP switches to RNR polling (to inhibit secondary response I-frame transmission) and
allows the client one to two seconds after broadcast completion to send more data
before reverting to normal (RR) polling automatically. If the data packet is sent via an
NRM secondary station and the station’s transmit window is still open, the ICP trans-
mits the data in a response I-frame with the F-bit reset to zero.
For NRM primary stations, bits 1 and 2 in the iProtModifier field indicate the frame
addressing mode requested by the client. If both bits 1 and 2 are reset to zero, the ICP
uses normal individual station addressing. If bit 1 is set to one and bit 2 is reset to zero,