User`s guide

70 DC 900-1317J
ADCCP NRM Programmer’s Guide
3.4.20.1 First Variant
The first variant of the DLI_PROT_CFG_LINK packet allows the client to configure a physical
link. The client must specify the
usProtCommand field (DLI_PROT_CFG_LINK), iProtModifier
field (0,) the link ID, usProtXParms[1] field (data size = 2 or 4), and the data area (see
Ta ble 3 –7 ).
Bits 0–3 in word 0 of the data area select the nominal baud rate. The client must specify
the nominal baud rate even if the clock source is external. The ICP bases the default
retry timer values upon this nominal baud rate and the maximum data size.
Bits 4 and 5 of word 0 must be zero.
Bit 6 in word 0 selects the transmit clock source (receive clocking is always externally
derived). Internal or external transmit clocking may be selected. When the client selects
external, the nominal baud rate specification need not be precise if the client adjusts the
station timer constants to values known to be correct (see Section 3.4.20.3).
Bits 7–15 of word 0 must be zero.
The use of word 1 of the data area, which configures the data encoding and electrical
interface for the link, is optional. If word 1 is used, the data size must be four bytes. If
the data size is two bytes, then word 1 is not used, the link’s data encoding is defaulted
to NRZ, and its electrical interface is defaulted to EIA-232.
Bits 0-7 of word 1 select the data encoding for the link. NRZ, NRZI, or ANRZI may be
selected. ANRZI (“asynchronous NRZI”) is a special use of NRZI encoding wherein the
receive clock is extracted from the data signal (while the transmit clock source is inter-
nal). 115200 bits/second is the highest data rate offered with ANRZI encoding.)
Bits 8-11 of word 1 select the electrical interface. EIA-232, EIA-449, EIA-530, or V.35
may be selected.
Bits 12-15 of word 1, when it is used, must be zero.