Managing ports (serial ports, parallel ports, USB ports, etc.)

ONLINE HELP
WINDEV, WEBDEV AND WINDEV MOBILE

Version:

Home | Sign in | English

Help

WLanguage

WLanguage functions

Standard functions

Windows management functions

Serial/Parallel Ports functions

Managing ports (serial ports, parallel ports, USB ports, etc.)

Overview

Serial port/parallel port/infrared port

USB port

Related examples

See also

Managing ports (serial ports, parallel ports, USB ports, etc.)

Overview

Several devices can be managed directly via a management of the ports used by these devices to communicate with the computer. Therefore, the management of a serial, parallel or infrared port can be used to directly manage a bar code reader or a print as you go.

WINDEV, WEBDEV and WINDEV Mobile allow you to manage the actions performed on these different ports.

Remarks:

This feature only affects the server computer.
Infrared ports are not supported.
Only serial ports are supported.
Only serial ports are supported.

Serial port/parallel port/infrared port

Several WLanguage functions can be used to easily manage the serial and parallel ports. All these functions start with the letter s.

You can for example:

open a serial or parallel port (sOpen) or close it (sClose).
write into a serial port (sWrite) or read its content (sRead).

For more details on the available functionalities, see Serial and parallel port management functions.

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.

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.

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

USB port

The management of a USB port does not depend on the port itself but on the device that is attached to it. The management of a USB port to which a printer is connected differs from the management of a USB port to which a scanner is connected. No management standard can be defined.

The USB port is not a passive port like the serial port or the parallel port. It is always subject to the use of a specific driver for the device used.

Therefore, WINDEV or WEBDEV does not manage the USB port but the device that is installed on this port. If the device installed is:

a printer, you have the ability to use the print functions.
a scanner, you have the ability to use the TWAIN functions,
...

In most cases, the devices connected to a USB port are supplied with a driver. We advise you handle this driver from WINDEV directly.

WINDEV offers USB functions to handle the elements accessible from a USB port.

Related Examples:

Unit examples (WINDEV): Direct print

[ + ] Direct print on a dot-matrix printer with the WLanguage functions.
The following topics are presented in this example:
1/ the functions for managing the communication ports
2/ sending sequences to a printer.

This example powered by WINDEV is used to directly print on the dot-matrix printer connected to the parallel port of your choice.
This example is using the WLanguage "sWrite" function.
This feature is very useful for the applications exploiting cash registers.
This example is not suited for a laser printer ; in this case, we recommend that you use the report editor of WINDEV.