Precautions - Omron NT20S-ST121B-EV3 User Manual

RS-232C Communications
Notification of Operation
at NT20 to the Host
Operation by Terminal
Commands
6-2-2

Precautions

Commands
Command Length
214
Host program
Receive notification
The terminal commands allow the NT20 to be used as a terminal of the Host
to display text and graphics independently of the screens stored in the NT20.
The Host sends a command and the NT20 processes the message. The
NT20 does not send back a response to the Host.
Host program
Message to PT
Some important points to consider when using commands are listed below.
If a personal computer is used as the host and a high-level language, such as
BASIC or C, is used for programming, commands are specified with ASCII
text strings.
In the descriptions in this section, parameters are given in lowercase letters.
When specifying commands, specify any text given in uppercase letters as is
and replace lowercase letters with ASCII text strings to specify the numeric
values of the parameters (BCD or hexadecimal) or the text strings for parame-
ters. Any text given in square brackets [ ], however, represents one control
code, such as ESC or CR.
In the descriptions of commands, "4-digit BCD" indicates an ASCII text string
of a 4-digit BCD value and "4-digit hexadecimal" indicates an ASCII text string
of a 4-digit hexadecimal value. Do not specify BCD or hexadecimal values
directly. Always use ASCII text strings to represent them.
Example
The command format for the Four-digit Numeral Memory Table Write com-
mand is as follows:
[ESC] C
1B 43
Assuming that the following parameters were to be specified, the text string
given below would actually be sent.
d d d : 014 (3-digit hexadecimal)
1 2 3
n n n n : 1234 (4-digit BCD)
1 2 3 4
[ESC] C
1B 43
Note In the descriptions of commands and responses, "**" indicates the specified
characters in ASCII (2-digit hexadecimal).
If a mistake during command specification results in a command being too
long, the correct length of the command is executed and the remainder is
ignored.
A timeout error results if a mistake during command specification results in a
command being too short.
Notification operating command
Terminal command
d d d n
1 2 3 1
* * * * * * * *
0 1 4 1
30 31 34 31
Section 6-2
NT20 operation
Send notification command
NT20 operation
Process message
n n n
2 3 4
* * * * * *
2 3 4
32 33 34