Omron NT20, Руководство пользователя

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RS-232C Communications Section 6-2
6-2 RS-232C Communications
This section describes the communications procedure when using the NT20-
ST128 (RS-232C), and program flow using examples in BASIC.
6-2-1
Communications
Procedure
The Host and NT20 communicate according to the following procedure.
1,2,3... 1. The RS-232C circuit must be opened (i.e., communications enabled) be-
fore communications can start.
2. Commands are used to control the PT and to receive notification from the
NT20.
3. Close the RS-232C circuit again after communications have been complet-
ed.
After a circuit has been opened, it can be used until it is closed again.
OPEN: Opens the RS-232C circuit. The Host communications condi-
tions are also set.
Refer to 3-5-7 Setting RS–232C Communications Conditions
(NT20-ST128) on page 99.
PRINT#: Sends an instruction via the RS-232C circuit to the NT20.
LINE INPUT#: Receives a command from the NT20. [LINE INPUT] is used
when receiving input delimited by commas (,) or double quo-
tation marks (").
CLOSE: Closes the RS-232C circuit.
Refer to the Host's BASIC Manual for more details about the
commands.
Operation by Operating
Commands The operating commands display monitored data from the production line and
messages to the factory workers. They are also used for NT20 control and
management.
The communications flow between the Host and NT20 differs according to the
following three cases:
Message from Host to
NT20
Enquiry from Host to NT20
Host program
RS-232C circuit
NT20 operation
OPEN command
PRINT # command
LINE INPUT # command
CLOSE command
Open circuit
Send instruction
Close circuit
Send instruction
Receive instruction
Send instruction
Open
status
Host program NT20 operation
Message to PT Process message
Message operating command
Host program NT20 operation
Enquiry operating command
Enquiry
Receive command
Receive command
Send response command
Response operating command