Envoy Application Programming Manual

BISYNC Multipoint Tributary Protocol
Envoy Application Programming Manual—427159-001
5-11
Address-List Format
Address-List Format
This subsection includes:
•
Station address on page 5-12
•
Poll List on page 5-12
•
Select List on page 5-12
The address list tells Envoy the poll and select addresses of the stations that the
application process represents. The address list is passed to Envoy, after the line has
been opened and before the first call to WRITE or READ, with a call to the
DEFINELIST procedure.
Each entry in the address list is referred to by an ordinal entry number; the first entry is
designated entry number 0. Envoy uses the entry number, following a READ
completion, to tell the application process which terminal responded to the poll. The
application process uses the entry number, in conjunction with a WRITE call, to tell
Envoy which terminal is to be selected. The application process and Envoy pass the
entry number back and forth by way of the entry number field of the message control
word (MCW) in the application’s read or write buffer.
The address list format consists of a poll list followed by a select list (Example 5-1
).
Example 5-1. Address List Format
station address, entry 0
station address, entry 0
.
. poll list
.
station address, entry pn-1
station address, entry pn
station address, entry pn+1 ______________
.
.
. select list
station address, entry n-1
________________________________
Legend
entry = entry number in the address list (first entry = 0)
pn = poll count
n = number of entries in the address list