Envoy Application Programming Manual

ADM-2 Multipoint Supervisor Protocol
Envoy Application Programming Manual—427159-001
7-9
Terminal Address
Terminal Address
Each entry in the address list is a terminal address. A terminal address is of the form:
NULL EOT a1 a1 p|q ENQ ! six characters.
a1 the terminal’s address character. The address character must be present twice.
p the entry used for polling the terminal.
q the entry used for selecting the terminal.
Poll List
The poll list contains one entry for each terminal to be polled (poll count). The most
significant bit of the first element of each entry in the poll list (that is, terminal address.0
is the poll-state bit. The state of this bit indicates whether the associated terminal should
be polled when polling is initiated:
0 = "enable polling"
1 = "disable polling" (do not poll the terminal associated with this address)
Select List
The select list immediately follows the poll list in the address list. It contains one entry
for each terminal that may be selected (the number of entries minus the poll count). The
entries in the select list must correspond exactly to the entries in the poll list.
The program in Example 7-2
shows how to build an address list:
Example 7-1. Address List
terminal address, entry 0
terminal address, entry 0
.
. poll list
.
terminal address, entry pn-1
terminal address, entry pn
terminal address, entry pn+1 ______________
.
.
. select list
terminal 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