Envoy Application Programming Manual

ADM-2 Multipoint Supervisor Protocol
Envoy Application Programming Manual—427159-001
7-10
Polling
This example has the following components:
•
The address list contains six entries.
•
The address list is defined as a STRING array so that individual byte elements can
be initialized.
•
Each terminal address consists of six characters.
•
The first three entries (poll^count) constitute the poll list.
•
The last three entries (num^entries minus poll^count) constitute the select list.
•
The terminal addresses in the select list match the terminal address in the poll list.
Polling
The application initiates polling by calling the READ procedure. This subsection
includes:
•
Polling Type on page 7-11
•
Polling Interval on page 7-15
•
Poll State on page 7-16
Example 7-2. Build an Address List
LITERAL addr^size = 3, ! address size in words.
num^entries = 6, ! number of address-list
!entries.
NULL = 0, ! ASCII NULL character.
EOT = 4, ! ASCII EOT character.
ENQ = 5, ! ASCII ENQ character.
poll^count = 3; ! number of poll-list entries.
STRING
.saddr^list[ 0 : addr^size * num^entries * 2 - 1] :=
! address list.
[NULL, EOT, "11p", ENQ, ! terminal 1 poll.
NULL, EOT, "22p", ENQ, ! terminal 2 poll.
NULL, EOT, "33p", ENQ, ! terminal 3 poll.
NULL, EOT, "11q", ENQ, ! terminal 1 select.
NULL, EOT, "22q", ENQ, ! terminal 2 select.
NULL, EOT, "33q", ENQ] ; ! terminal 3 select.
INT .addr^list := @saddr^list ’>>’ 1; ! redefine as INT
!array.
CALL DEFINELIST (linefnum,addr^list,addr^size,num^entries,
poll^count,poll^type);
IF < THEN ...