Maple Systems STEPware-100 - Manual (Page 42)

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 data from F3 keypress
ETX
OIT #100 responds with its network address, the
contents of the Keyboard Output Buffer (which
happens to contain the ASCII string sent when
the F3 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 data from F3 keypress
ETX
OIT #100 resends the last transmission and ends
with the line terminator.
Operating Modes 39
1010-0096, Rev. 04