Maple Systems MAP450D - Manual (Page 23)

Sample Network Session
Below is a sample session showing a host controller communicating with three OITs on a
multidrop network. The OITs have network addresses of 1, 30, and 100. The line
terminator is set to
ETX
.
NOTE:Spaces are shown for clarity only and should not be used.
Source Message Description
Host 00
ESC
m 25
ETX
The host controller sends a global command
telling all terminals to display Message #25.
Notice that the host controller ended with a line
terminator. This “logs off” all of the OITs.
Host 01
ESC
e HELLO!
STX
The host controller sends an echo command as a
“log on” to OIT #1. Notice that the host controller
ends with a command terminator instead of a line
terminator. This allows the host controller to
continue communicating with OIT #1 without
having to send another network address.
OIT #1 01 HELLO!
ETX
OIT #1 responds with its network address, the
characters received from the host controller, and
a line terminator.
Host
ESC
?
STX
The host controller requests the keyboard status
of OIT #1. Notice that the host controller does
not specify a network address, since the host
controller has not sent a line terminator yet.
OIT #1 01 0
ETX
OIT #1 responds that no characters are currently
stored in the Keyboard Input Buffer and ends
with a line terminator.
Host
ESC
e BYE!
ETX
The host controller sends an echo command as a
“log off” to OIT #1. Notice that the host
controller ended with a line terminator. Now the
other OITs will listen for a new network address.
OIT #1 01 BYE!
ETX
OIT #1 responds with its network address, the
characters received from the host controller, and
a line terminator.
Host 1E
ESC
w 5
ETX
The host controller “logs on” to OIT #30 and
creates a five character display variable at the
current cursor position. Notice that the host
controller ended with a line terminator to “log
off” OIT #30.
Host 64
ESC
p
STX
The host controller “logs on” to OIT #100 and
polls the Keyboard Output Buffer contents.
OIT #100 64 A
ETX
OIT #100 responds with its network address, the
contents of the Keyboard Output Buffer (which
happens to contain the ASCII character sent when
the A key was pressed), and the line terminator.
Host
ESC
r
ETX
The host controller asks OIT #100 to resend the
last transmission.
OIT #100 64 A
ETX
OIT #100 resends the last transmission and ends
with the line terminator.
Chapter 2: Operating Modes 22
1010-0101, Rev. 00