Link Layer - Motorola MOSCAD 68P02958C00-B User Manual

will start transmitting only after a delay that is equal to this parameter multiplied by the RTU's
priority level. If in the meantime the channel has been taken by a higher-priority RTU, the
whole process is repeated when the channel is free again.
For example, let's assign the time resolution T. When the RTU accesses the channel, it starts
transmitting only after a delay that is a factor of T. When the RTU accesses the channel for the
first time, the delay is (n+4) T, where n represents the 4 less significant bits in the address. When
an RTU sends an acknowledgment to another RTU, it will start transmitting only after a delay of
0 to 3T. If a collision occurs because two RTUs have been addressed with the same 4 less
significant bits, then the address bits are shifted automatically, and the RTU starts transmitting
after a different delay.
Channel monitor override delay: <0-3200> 100 mSec
Defines the delay after which the RTU will transmit its message even if the communications
channel is busy. The default value of 0 means that this feature is disabled (i.e., the RTU will
not transmit if the channel is busy).
Data repeat mode: <Yes / No>
Not used.
For future use. To implement the store and forward feature by hardware. It is applicable in
case the piggyback modem is DFM, FSK, or COS.
Minimum time to retry: <0-2500> mSec
The minimum time (in msec) that the RTU will wait before retransmitting an unacknowledged
message.

Link Layer

This section reviews the parameters through which you can control the functioning of the Link
Layer.
Link type
Not supported yet. Select the Standard link type to establish a link that requires ACKs.
Otherwise select Fast Link (no ACK).
TX queue size <2^3-2^9>
This is the maximum number of MDLC frames that can be placed in the transmission queue
before a transmission process starts.
Number of ACK buffers <5-50>
The reception process of the Data Link layer prepares an ACK for each received data frame,
and is capable of issuing, in a single ACK message, up to 57 ACKs for data frames that arrived
in uninterrupted sequence. This parameter determines the number of ACK buffers in which
ACKs are prepared and moved to transmission before the "Cannot get ACK buffers" message
is issued to the Error Logger. This message means that the acknowledging side is unable to
move to ACK transmission because of heavy reception traffic, or because it cannot access a
channel for transmission.
5-43
Site Configuration
[0]:
[No]:
[0]:
[Standard]:
[2^6]:
[8]: