HL LOGICAL LINK (870)    FILE (1)

Name Value
NAME HL LOGICAL LINK
DESCRIPTION
This file serves two purposes. It is a fileman-compatible transmission
characters define the beginning and end of a message (LLP START BLOCK
and LLP END BLOCK).
 
This file also stores information that drives the SYSTEMS LINK MONITOR
display option. Fields like, IN QUEUE FRONT POINTER, IN QUEUE BACK 
POINTER are used to manage the data flow in the queues but they are
also displayed on the SYSTEMS LINK MONITOR under the alias's MESSAGES
PROCESSED and MESSAGES RECEIVED. Fields like STATE and DEVICE TYPE
are also used to drive the SYSTEMS LINK MONITOR. These fields are
updated by the lower layer protocols in order to give real-time feedback
log. The Low Layer Protocols write and read directly from this file.
as to what is ocurring on a link. For example, when a message is 
received (see HLCSDR1) the state transitions from "IDLE" to "READING".
(See routines HLCSDR1 and HLCSDR2)
 
This file stores parameters that govern the behaviour of the Low Layer
Protocols. Fields like: READ TIMEOUT, ACK TIMEOUT, LLP START BLOCK, and
LLP END BLOCK, are fields that govern how long the finite state machine
waits for data to come down the line (READ TIMEOUT), how long it waits
for a lower level acknowledgement (ACK TIMEOUT), and which control