sOpen (Function)

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Standard functions

Windows management functions

Serial/Parallel Ports functions

sOpen

Presentation

Example

Operating mode

Using an external library: RXTX

Features specific to Android and Android widget

See also

sOpen (Function)

In french: sOuvre

Opens and initializes:

a serial port.
a parallel port.
an infrared port. In this case, only the second syntax is available.

The default values are as follows:

Transfer rate: 9600 Bauds
Parity: None
8 data bits
1 stop bit

Parallel and infrared ports are not supported.

This function affects the server.

Example

See additional examples

// Open COM1 (using the port number)
LineCom1 = sOpen(1, 2000, 2000)
IF LineCom1 = True THEN
// Configure COM1: Rate 9600, even parity,
// 8 data bits, 1 stop bit
sParameter(1, 9600, 1, 8, 0)
// Rest of process...
// Close COM1
sClose(1)
ELSE
Error("Error while opening COM1")
END

// Open IR1 (using the port name)
IR1 = sOpen("IR1", 2000, 2000)
IF IR1 <> 0 THEN
// Configure IR1
sParameter(IR1, 9600, 1, 8, 1)
// Rest of process...
// Close IR1
sClose(IR1)
ELSE
Error("Error while opening IR1")
END

Syntax

Not available in Linux, Android and Android widget

Opening and initializing a port by specifying its number Hide the details

<Result> = sOpen(<Port number> , <Size of input buffer> , <Size of output buffer> [, <Timeout> [, <Managing events>]])

<Result>: Boolean

True if the port was opened and initialized,
False otherwise.

<Port number>: Integer

Number of relevant port:
Number of the serial port: 1, 2, 3, ... 256 for COM1, COM2, COM3, ... COM256.
Number of the parallel port: -1, -2, -3 or -4 for LPT1, LPT2, LPT3 or LPT4.

<Size of input buffer>: Integer

Size of input buffer in bytes (up to 32768).

<Size of output buffer>: Integer

Size of output buffer in bytes (up to 32768).

<Timeout>: Optional integer or optional Duration

Duration (expressed in milliseconds) for reading or writing a character. If <Timeout> is set to 1s when writing 1024 bytes, the waiting time will be 1024s.
This parameter is used to avoid a lock when a read or write problem occurs on the print port.
New in version 28
if <Timeout> is negative, the waiting time will be constant. For example, if <Timeout> time is set to "-1s" when reading 1024 bytes, the waiting time will be 1s.
When <Timeout> has expired, the read or write function returns 0.
The default value of this parameter is defined at system level.
The sDefaultTimeout constant allows you to use the default timeout.
This parameter can be:
an integer corresponding to the number of milliseconds,
a Duration variable,
the duration in a readable format (e.g., 1 s or 10 ms).
No timeout will be applied if this parameter is not specified. The sDefaultTimeout constant is not available. If a timeout is specified, it will be applied to the read operations performed on the serial ports.

<Managing events>: Optional boolean

True to detect the events on the serial port,
False (default value) to avoid managing the events. These events can be managed by sEvent.

Opening and initializing a port by specifying its name Hide the details

<Result> = sOpen(<Port name> , <Size of input buffer> , <Size of output buffer> [, <Timeout>])

<Result>: Integer

Identifier of open port. This identifier can be used in the functions for managing ports.
This identifier corresponds to:
the number of the relevant serial port: 1, 2, 3, ... 256 for COM1, COM2, COM3, ... COM256.
the number of the relevant parallel port: -1, -2, -3 or -4 for LPT1, LPT2, LPT3 or LPT4.
the number of the relevant infrared port: 1, 2, 3, ... 256 for IR1, IR2, IR3, ... IR256.
0 if an error occurs.
Caution:
This identifier does not correspond to the serial port number.
Parallel port management is not available.
Infrared ports are not supported.

<Port name>: Character string

Name of relevant port:
Name of serial port::
COM1, COM2, COM3, ... COM256.
Name of serial port in Java: /dev/ttyS4, /dev/ttyS5, ... /dev/ttyS9.
Serial port number in Linux (for example /dev/ttyS1).
Name of the serial port returned by sListPort.
Name of parallel port: LPT1, LPT2, LPT3 or LPT4.
Name of infrared port: IR1, IR2, ... IR256.
Reminder:
Parallel port management is not available.
Infrared ports are not supported.

<Size of input buffer>: Integer

Size of input buffer in bytes (up to 32768).

<Size of output buffer>: Integer

Size of output buffer in bytes (up to 32768).

<Timeout>: Optional integer

Duration (expressed in milliseconds) for reading or writing a character. If <Timeout> is set to 1s when writing 1024 bytes, the waiting time will be 1024s.
This parameter is used to avoid a lock when a read or write problem occurs on the print port.
New in version 28
if <Timeout> is negative, the waiting time will be constant. For example, if <Timeout> time is set to "-1s" when reading 1024 bytes, the waiting time will be 1s.
When <Timeout> has expired, the read or write function returns 0.
The default value of this parameter is defined at system level.
The sDefaultTimeout constant allows you to use the default timeout.
This parameter can be:
an integer corresponding to the number of milliseconds,
a Duration variable,
the duration in a readable format (e.g., 1 s or 10 ms).
No timeout will be applied if this parameter is not specified. The sDefaultTimeout constant is not available. If a timeout is specified, it will be applied to the read operations performed on the serial ports.

Remarks

Operating mode

A port cannot be opened if this port was not closed properly.
Important: A port must be opened by sOpen before it can be configured by sParameter.
WLanguage does not allow you to manage the control signals.
Two computers send each other characters via a port: if the second computer calls sOpen once the characters have been sent by the first computer, these characters are ignored.

Remarks:

If the WIN.INI file contains initialization values for the specified serial port, these values are used.
The following entries of the registry return the list of serial ports and parallel ports:
- "HKEY_LOCAL_MACHINE\HARDWARE\DEVICEMAP\SERIALCOMM" for the serial ports.
- "HKEY_LOCAL_MACHINE\HARDWARE\DEVICEMAP\PARALLEL PORTS" for the parallel ports.

Special case for Linux:

Only serial ports can be opened and initialized.
By default, users do not have access to serial ports. It is necessary to grant them specific rights to manage serial ports.

Using an external library: RXTX

In Java, the use of functions for handling the serial and parallel ports (sOpen, sWrite, sRead, ...) requires the presence of an external library: RXTX.

This library includes a Jar archive and one or more native libraries that depend on the operating system on which the application is run. To use these functions:

the Jar archive (RXTXComm.jar) must:
- be found in the same directory as the Java application generated by WINDEV,
- be found in the execution classpath of the application,
- be directly included in the generated application (from the wizard for Java generation).
the native libraries corresponding to the operating system on which the application is run must be found:
- in the same directory as the Java application generated by WINDEV,
- in the path of the application libraries (librarypath).

The RXTX library and its documentation can be downloaded from: http://users.frii.com/jarvi/rxtx/index.html (link valid at the time this documentation was published).

Caution: The management of infrared ports is not available in Java.

Features specific to Android and Android widget

In Android and Android widget mode, the serial and parallel port functions can be used:

Only on serial (not parallel or infrared) ports.
Only with devices that support the CDC/ACM protocol (Arduino ATmega32U4) and the following USB to serial converter chips:
- FTDI FT232R, FT232H, FT2232H, FT4232H, FT230X, FT231X, FT234XD
- Silabs CP210x
- Qinheng CH340, CH341A
- Prolific PL2303

Specific features of sOpen:

Only serial ports can be opened and initialized.
The user will see a dialog box to allow the application to connect to the device.
This function must be called in the main the thread of the application.
Events are not supported.
Only the syntax to open and initialize a port by specifying its name is available.

Business / UI classification: Business Logic

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