Envoy Application Programming Manual

ADM-2 Multipoint Supervisor Protocol
Envoy Application Programming Manual—427159-001
7-20
Normal Text
The ADM-2 multipoint supervisor protocol accepts the following types of message
formats:
•
Normal Text on page 7-20
•
Sequential Select on page 7-20
•
Fast Select on page 7-21
•
Broadcast Select on page 7-22
•
Send Function on page 7-23
Normal Text
Normal text is indicated by messages of the form:
message = STX-text-ETX
(message length = 2 + text length)
The following message format is received by the application process if the terminal
operation presses a function key (F1:F16):
message = SOH c ETX
(message length = 5)
where c is an ASCII character that indicates which key was pressed (@, A, B ... O, or ’,
a, b, ... o).
Sequential Select
A sequential-select function is used to display a message on a group of terminals. The
group is defined by a list of terminal addresses included in the message format.
Addressed terminals that are not busy when the message is sent display the text; busy
terminals ignore the message.
The sequential-select function is performed by writing a message of the form:
MCW.<6> = 1 (special-format message)
MCW.<8:15> = 0
EOT a1 a1 ra2 a2 r...an an s STX--text--ETX
a1 is the one-byte terminal address of the first terminal to receive the
message
a2 is the one-byte terminal address of the second terminal to receive the
message
an is the one-byte terminal address of the last terminal to receive the
message
r is a one-byte sequential-select function code
s is a one-byte fast-select function code