Maple Systems OIT Family (ASCII) - Manual (Page 19)

Below is a sample session showing an ASCII host communicating with three OITs on a multidrop
network.TheOITshavenetworkaddressesof1,30,and100.ThelineterminatorissettoETX.
Source Message Description
Host 00
ESC
M 25
ETX
The ASCII host sends a global command telling
all terminals to display Message #25.
Host 01
ESC
A HELLO!
STX
The ASCII host sends an echo command as a “log
on” to OIT #1. Notice that the ASCII host does not
end with a line terminator but instead uses the
command terminator. This allows the ASCII host
to continue to communicate with OIT #1 without
having to “log on” with another network address.
OIT #1 0 HELLO!
ETX
OIT #1 responds with no error, echoes the
characters received from the ASCII host, and
ends with a line terminator.
Host
ESC
R C 0500 1
STX
The ASCII host asks OIT #1 for the current bit
value of OIT coil address C500. Notice that the
ASCII host does not have to specify a network
address, since the ASCII host has not sent a line
terminator yet. Notice also that the memory
address must be four digits (0500).
OIT #1 0 1
ETX
OIT #1 responds with no error, the value (1) of OIT
coil address C500, and ends with a line terminator.
Host
ESC
A BYE!
ETX
The ASCII host sends an echo command as a
“log off” to OIT #1. Notice that the ASCII host
sent the line terminator. Now the other OITs will
listen for a new network address.
OIT #1 0 BYE!
ETX
OIT #1 responds with no error, echoes the
characters received from the ASCII host, and
ends with a line terminator.
Host 1E
ESC
W D 0012 3 543
ETX
The ASCII host “logs on” to OIT #30 and writes
the value 1,347 (543 hex) into the 16-bit register
at D12. Notice that leading zeroes are not
required on the data value (543).
OIT #30 0
ETX
OIT #30 responds with no error and ends with a
line terminator.
Host 64
ESC
P
STX
The ASCII host “logs on” to OIT #100 and polls
the OIT’s buffer contents.
OIT #100
0
ESC
X D 0001 4 03072523
STX
ESC
X C 0725 1 1
STX
data from F3 keypress
ETX
OIT #100 responds with no error, the new value of
50,799,907 (03072523 hex) in D1, the new value
of 1 in C725, the ASCII string sent when the F3
key was pressed, and then ends with the line
terminator. The “Notify Host of Read/Write
Register Monitor Updates” feature must be
enabled for the OIT to notify the ASCII host of
the changes to the values in D1 and C725.
Host
ESC
Q
ETX
The ASCII host asks OIT #100 to resend the last
transmission.
OIT #100
0
ESC
X D 0001 4 03072523
STX
ESC
X C 0725 1 1
STX
data from F3 keypress
ETX
OIT #100 responds with no error, resends the
last transmission, and ends with the line
terminator.
18 OIT Family Operation Manual (ASCII)
1010-0088, REV02