1 Introduction

1.1 Features
1.2 Documentation Set
1.3 Example Program
1.4 Installation
1.5 Uninstalling
1.6 Pricing
1.7 Updates

2 Library Overview

2.1 Dynamic Link Libraries
2.2 Key Codes
2.3 Win32 STDCALL and DECLSPEC
2.4 Limitations on COM Ports
2.5 INCLUDE Files
2.6 Dynamic Strings
2.7 Waiting for New Serial Data
2.8 Error Display
2.9 SioEvent Logic
2.10 Virtual Serial Ports
2.11 WSC Declaration File
2.12 Adding WSC to an Xbase++ Program

3 Compiler Issues

3.1 Xbase++ Compiler
3.2 Compiling and Linking Programs

4 Example Programs

4.1 WSCVER
4.2 SIMPLE
4.3 XMS and XMR
4.4 YMS and YMR
4.5 FINDER
4.6 ATOK
4.7 DEVICE
4.8 DIALER
4.9 SELFTEST
4.10 EVENT

5 Revision History

1 Introduction

The Windows Standard Serial Communications Library for Xbase++ (WSC4XB) is a component library of functions providing the capability to quickly write serial communication applications in Xbase++. The WSC component library uses the standard Windows API (Application Programmer's Interface) to communicate with any device connected to a serial port.

A straightforward interface is provided to access data from a serial port using RS232 or multi-drop RS422 or RS485 ports. WSC also supports virtual serial ports using Bluetooth serial and USB-to-serial converters.

The Windows Standard Serial Communications Library for Xbase++ (WSC4XB) supports and has been tested with all versions of Alaska Xbase++. WSC4XB includes numerous Xbase++ example programs that demonstrate serial port communications to help software developers easily build software applications using the WSC SDK.

WSC has been tested on multiple computers running Windows 95/98, Windows Me, Windows NT4, Windows 2000, Windows XP and Windows Vista. A Win32 DLL is provided. The WSC DLL (WSC32.DLL) can be used from any 32-bit language (C/C++, Visual C++ .NET, Visual C#, Visual FoxPro, Visual Basic, VB.NET, Visual FoxPro, Visual dBase, and Delphi) capable of calling the Windows API.

When comparing the Windows Standard Serial Communications Library against our competition, note that:

1. WSC4XB is a standard Windows DLL (NOT an OCX or ActiveX control) and is much smaller than a comparable OCX or ActiveX control.
2. WSC does NOT depend on ActiveX or Microsoft Foundation Class (MFC) libraries or similar "support" libraries.
3. The WIN32 version of WSC is fully thread safe.
4. The WSC functions can be called from applications not capable of using controls.

MarshallSoft also has versions of the Windows Standard Serial Communications Library for Visual C/C++ (WSC4C), Delphi (WSC4D), Visual Basic (WSC4VB), Visual FoxPro (WSC4FP), Visual dBASE (WSC4DB), and PowerBASIC (WSC4PB). All versions of WSC use the same DLLs (WSC16.DLL or WSC32.DLL). However, the examples provided for each version are written in the specified computer environment. Development time is shortened in multi-language projects because programmers need only learn one interface.

The latest versions of the Windows Standard Serial Communications Library (WSC) can be downloaded from our web site at http://www.marshallsoft.com/serial-communication-library.htm

Our goal is to provide a robust serial communication library component that you and your customers can depend upon. A fully functional evaluation version is available. Contact us if you have any questions.

1.1 Features

Some of the many features of the Windows Serial Communications Library are:

• Can control any serial device connected to the serial port.
• Can control multiple ports (up to 256 ports) simultaneously.
• Can be used with virtual serial ports using Bluetooth serial or a USB to serial converter.
• Includes 34 functions plus modem control.
• Comes with ANSI emulation and ASCII, XMODEM and YMODEM.
• Supports hardware and software flow control.
• Supports any baud rate (32-bit version).
• Ability to specify the parity, word size, and number of stop bits.
• Supports binary and text data transfer.
• Is fully thread safe.
• Supports Windows 95/98/Me/NT/2000/2003/XP.
• Supports character peek (SioEventChar).
• Implemented as a standard Windows DLL, which will work with all versions of Windows.
• Can send Windows messages on completion of events (incoming character, etc.)
• Supports all versions of Alaska Xbase++.
• Does not depend on support libraries. Makes calls to core Windows API functions only.
• Can be used with any program (in any language) capable of calling Windows API functions such as Visual C++, Visual C++ NET, Visual Basic, VB.NET, Visual FoxPro, Delphi, PowerBASIC, dBASE, COBOL, Access and Excel.
• Can be purchased with or without source code.
• Updates are free for one year (updates to DLL source code are separate).
• Royalty free: there are no run-time fees.
• The evaluation version is fully functional (60 day evaluation period).

Also see WSC versions for other supported languages:

• http://www.marshallsoft.com/wsc4c.htm (C/C++,C#,.NET)
• http://www.marshallsoft.com/wsc4d.htm (Delphi)
• http://www.marshallsoft.com/wsc4vb.htm (Visual Basic, VB.Net, VBA languages)
• http://www.marshallsoft.com/wsc4fp.htm (Visual FoxPro)
• http://www.marshallsoft.com/wsc4db.htm (dBase)
• http://www.marshallsoft.com/wsc4pb.htm (PowerBASIC)

A good selection of Xbase++ programs with full source code is included. Refer to Section 4 for more details on each of the example programs.

     [PROGRAM]    [DESCRIPTION]
     WSCVER     :  Program that displays the WSC version number.
     SIMPLE     :  A simple terminal emulator.
     FINDER     :  Finds a modem connected to one of your serial ports.
     XMS , XMR  :  XMODEM programs.
     YMS , YMR  :  YMODEM programs.
     DEVICE     :  Program sends string to serial device.
     DIALER     :  Dials up host (or BBS).
     ATOK       :  Forms based program that sends "AT" to modem.
     SELFTEST   :  Performs port functionality testing.
     EVENT      :  A terminal emulator that uses SioEventWait.

1.2 Documentation Set

The complete set of documentation consists of four manuals in three formats. This is the first manual (WSC_4XB) in the set.

• WSC_4XB Programmer's Manual (WSC_4XB.DOC, WSC_4XB.TXT, WSC_4XB.HTM)
• WSC User's Manual (WSC_USR.DOC, WSC_USR.TXT, WSC_USR.HTM)
• WSC Reference Manual (WSC_REF.DOC, WSC_REF.TXT, WSC_REF.HTM)
• SERIAL User's Manual (SERIAL.DOC, SERIAL.TXT, SERIAL.HTM)

The WSC_4XB Programmer's Manual is the language specific (Xbase++) manual. All language dependent programming issues are discussed in this manual. Information needed to compile your programs in an Xbase++ environment is provided in this manual.

The WSC User's Manual (WSC_USR) discusses language independent serial communications programming issues including modem control. Purchasing and license information is also provided.

The WSC Reference Manual (WSC_REF) contains details on each individual WSC function.

The Serial Communications Manual (SERIAL) contains background information on serial port hardware.

Each manual comes in three formats:

• Microsoft Word (files ending in .DOC). The best format for printing manuals.
• Hyper Text (files ending in .HTM). Use any web browser to read.
• ASCII Text (files ending in .TXT).

Documentation is also provided online at
http://www.marshallsoft.com/wsc4xb.htm

1.3 Example Program

The following example demonstrates the use of some of the library functions:

     #INCLUDE "DLL.CH"
     #INCLUDE "WSC32.CH"
   
     Procedure Main()
     LOCAL Version
     LOCAL A, B, C
   
     ? "WSCVER 10/08/2007"
     ?
     * pass the key code
     if xSioKeyCode(WSC_KEY_CODE) < 0
       ?"ERROR: Bad Key Code!"
       return
     endif
     Version = xSioInfo(ASC("V"))
     * Compute WSC version
     A = int(Version / 256)
     Version = Version - (256 * A)
     B = int(Version / 16)
     C = Version - (16 * B)
     ? "WSC Version: " + LTRIM(Str(A)) + "." + LTRIM(Str(B)) + "." + LTRIM(Str(C))
     return

Refer to the WSC Reference Manual (WSC_REF) for individual function details.

1.4 Installation

1. Before installation of WSC4XB, your Xbase++ compiler should already be installed on your system and tested.
   
   
2. Unzip WSC4XB43.ZIP (or WSC4XB.ZIP for registered users) using any Windows unzip program.
3. Run the installation program SETUP.EXE which will install all WSC4XB files, including copying WSC32.DLL to your Windows directory. No Windows system files are modified.

Note that the Windows registry is not modified.

1.5 Uninstalling

Uninstalling WSC4XB is very easy. WSC does not modify the registry.

First, run UNINSTAL.BAT, which will delete WSC32.DLL from your Windows directory, typically C:\WINDOWS for Windows 95/98/Me/XP/Vista or C:\WINNT for Windows NT/2000. Next delete the WSC project directory created when installing WSC4XB.

1.7 Pricing

A developer license for WSC4XB can be registered for $115 (or $195 with ANSI C source code to the library DLL's). Purchasing details can be found in Section 1.3 "How to Purchase" in the WSC User's Manual (WSC_USR.HTM). Also see INVOICE.TXT provided with the evaluation person or order directly on our web site at

    http://www.marshallsoft.com/order.htm

1.8 Updates

When a developer license is purchased, the developer receives a new registered DLL plus a license file (WSCxxxx.LIC) that can be used to update the registered DLL for a period of one year from purchase. Updates can be downloaded from

   
     http://www.marshallsoft.com/oem.htm
   

After one year, your license must be updated if you want to be able to download updates. Your license can be updated for $30 if ordered within one year of the original purchase (or previous update). After one year, licenses can be updated for $55. Updates to the source code can be purchased for $40.

Note that the registered DLL's do not expire. After one year, your license must be updated if you want to be able to download updates. Your license can be updated for :

• $30 if the update is ordered within one year of the original purchase (or previous update).
• $55 if the update is ordered between one and three years of the original purchase.
• $75 if the update is ordered after three years of the original purchase.

If source code was previously purchased, updates to the source code can be purchased for $50 along with the DLL update. Note that the registered DLL's never expire.

2 Library Overview

The Windows Standard Serial Communications Library (WSC) has been tested on multiple computers running Windows 95/98/Me/XP/Vista, and Windows NT/2000.

2.1 Dynamic Link Libraries

The WSC4XB serial communication library component includes a Win32 dynamic link library (DLL). A DLL is characterized by the fact that it need not be loaded until required by an application program and that only one copy of the DLL is necessary regardless of the number of application programs that use it. Contrast this to the traditional static library that is bound to each and every application that uses it at link time.

An important advantage that DLLs have over other "popular" library formats such as VBX or OCX is that DLLs are callable by all Windows applications. Since DLLs are the building blocks of the Windows Operating System, they will not be replaced by a "newer technology".

2.2 Keycode

The WSC32.DLL has a keycode encoded within it. Your keycode is a 9 or 10-digit decimal number (unless it is 0), and will be found in the file KEYCODE.CH. The keycode for the evaluation (shareware) version is 0. You will receive a new keycode and a set of new DLL's when registering. The KEYCODE is passed to SioKeyCode.

If an error message (value -108) is received when calling SioKeyCode, it means that the keycode in your application does not match the keycode in the DLL. After registering, it is best to remove the evaluation version of the WSC32.DLL from the Windows search path or delete them.

2.3 Win32 STDCALL and DECLSPEC

WSC32 is written in ANSI C and is compiled using the STDCALL and DECLSPEC keywords. This means that WSC4PB uses the same calling conventions and file naming conventions as the Win32 API. . In particular, function names are NOT decorated. There are neither leading underscores nor trailing "@size" strings added to function names.

Any Windows application program may call the WSC32.DLL functions provided that the proper declaration file is used.

2.4 Limitations on COM Ports

The 32-bit version of WSC4XB (WSC32.DLL) can use any port from COM1 to COM256, provided that the port is known to Windows 95/98/NT/2000/Me/XP/Vista and there is physical hardware present.

2.5 INCLUDE Files

All example programs include the file WSC32.CH. The file WSC32.CH contains all the necessary constants and function declarations for WSC4XB. The Xbase++ include file DLL.CH is also required. For example,

     #INCLUDE "DLL.CH"
     #INCLUDE "WSC32.CH"

2.6 Dynamic Strings

A string in the C language (in which WSC and Windows are written) consists of a pointer to the first byte of a character buffer in which a zero byte ends the string characters.

When passing a string buffer to a DLL function into which text will be copied, it is strongly recommended that the local string be allocated immediately before use. For example, a string buffer is passed to the user defined dllGetMessage function , which copies a text message into it. Note that SPACE(80) is called immediately before xSioWinError.

     Procedure SayError(ErrCode)
        LOCAL Code
        LOCAL Buffer
        if ErrCode < 0
          ? "ERROR " + STR(ErrCode)
          Buffer = SPACE(128)
          Code = xSioWinError(@Buffer, 128)
          if Code > 0
            ? Left(Buffer,Code)
          endif
        endif
     return

This technique is not necessary for passing a string to a DLL function, only when passing a buffer to a DLL into which data is to be placed by the DLL function.

2.7 Waiting for New Serial Data

All serial data is moved from the UART's buffer to the receive queue in memory (by the Windows serial port driver) under interrupt control. Similarly, all out going serial data is moved to the transmit queue in memory.

There are several methods that can be used to receive incoming serial data. SioGetc and SioGets can be called directly. Note that if there is no input data available, SioGetc returns WSC_NO_DATA while SioGets returns zero. Also see section 2.9 "SioEvent Logic".

2.8 Error Display

The error message text associated with WSC error codes can be displayed by calling SayError (refer to Errors.prg). Each sample program contains examples of error processing.

2.9 SioEvent Logic

SioEvent, SioEventChar, and SioEventWait will block until the specified event occurs. If a call to SioEvent, SioEventChar, or SioEventWait is placed in a thread, then the thread will block but the application calling the thread will not.

SioEventWait is used in the Event.prg example program.

2.10 Virtual Serial Ports

A "virtual" serial port is COM port that appears to be a real RS232 serial port to the Windows API (and thus to WSC), but is in reality a COM port emulator.

The two most common virtual ports are those created for USB/serial port converters and Blue Tooth. WSC does not access the USB directly but will work with most USB-to serial port converters and with Bluetooth serial.

More information about Virtual serial ports can be found in Section_2.12 of the WSC User's Manual (WSC_USR). (http://www.marshallsoft.com/wsc_usr.htm#Section_2.12 )

2.11 WSC Declaration File

All WSC functions are declared in the WSC declaration file WSC32.CH. This file can be copied to the Xbase++ INCLUDE directory (where Xbase++ can find it) if so desired.

Note that each function is declared with the prefix character of 'X'

2.12 Adding WSC To An Xbase++ Program

Add the two INCLUDE statements

     #INCLUDE "WSC32.CH"
     #INCLUDE "KEYCODE.CH"

after

     #INCLUDE "DLL.CH"
   

Be sure that SioKeyCode is the first WSC function called. Note that the key code constant passed to SioKeyCode is found in the file KEYCODE.CH. This value will be 0 for the evaluation version and an 8 to 10 digit value for the purchased version.

Compile and link with WSC32.LIB. For example, to compile and link the (console mode) example program SIMPLE.PRG:

     xpp simple.prg
     alink /subsystem:console simple.obj wsc32.lib
   

3 Compiler Issues

The WSC4XB library works with all versions of Xbase++.

3.1 Xbase++ Compiler

If you don't have the Alaska Software Xbase++ compiler, you can find it on the web at

     http://www.alaska-software.com
   

3.2 Compiling and Linking Programs

Details about each of the example programs are provided in Section 4.0 "Example Programs".

To compile and link console mode programs such as SIMPLE.PRG, use:

     xpp simple.prg
     alink /subsystem:console simple.obj wsc32.lib

To compile and link windows GUI programs such as ATOK.PRG, use:

     xpp atok.prg
     alink /subsystem:windows atok.obj wsc32.lib

Some programs (such as XMR.PRG, XMS.PRG, YMR.PRG, and YMS.PRG) require the XYM32.DLL module and must be linked with XYM32.LIB.  For example,

     alink /subsystem:console xms.obj wsc32.lib xym32.lib

Also, some programs (such as FINDER.PRG) require the MIO32 module and must be linked with MIO32.LIB. For example,

     alink /subsystem:console finder.obj wsc32.lib mio32.dll

4 Example Programs

Before writing your own programs, compile and run the example programs.

4.1 WSCVER

The first example program is the program WSCVER (WSC Version) that displays the WSC library version number.

     xpp wscver.prg
     alink /subsystem:console wscver.obj wsc32.lib

4.2 SIMPLE

SIMPLE is a very simple communications program using WSC4XB. Everything that is typed on the keyboard is sent to the serial port, and everything incoming from the serial port is displayed on the screen.

The easiest way to test SIMPLE is to connect to a modem. Typing 'AT' should result in an 'OK' being displayed.

A null-modem cable can also be used to connect two computers together with their serial ports. Run SIMPLE on both machines. Whatever is typed on one machine will be displayed on the other.

     xpp simple.prg
     alink /subsystem:console simple.obj wsc32.lib

4.3 XMS and XMR

XMS (XMODEM Send) and XMR (XMODEM Receive) are programs that send and receive files using the XMODEM protocol.

     xpp xms.prg
     alink /subsystem:console xms.obj wsc32.lib xym32.lib

     xpp xmr.prg
     alink /subsystem:console xmr.obj wsc32.lib xym32.lib

4.4 YMS and YMR

YMS (YMODEM Send) and YMR (YMODEM Receive) are console mode programs that send and receive files using the YMODEM protocol.

     xpp yms.prg
     alink /subsystem:console yms.obj wsc32.lib xym32.lib

     xpp ymr.prg
     alink /subsystem:console ymr.obj wsc32.lib xym32.lib

4.5 FINDER

The FINDER program is a program that searches for a connected modem. Your modem must be connected to one of COM1 through COM4, and the modem must be turned on. FINDER takes no arguments. Note that FINDER uses the MIO module.

     xpp finder.prg
     alink /subsystem:console finder.obj wsc32.lib mio32.dll

4.6 ATOK

The ATOK program was developed using the Forms Designer (XPPFD) and is the only graphical example.

The ATOK program sends "AT" to a connected modem and expects an "OK" back.

     xpp atok.prg
     alink /subsystem:windows atok.obj wsc32.lib

4.7 DEVICE

The DEVICE program is designed for talking to an arbitrary serial device. Use this program as a guide when communicating with all serial devices other than modems and other computers.

     xpp device.prg
     alink /subsystem:console device.obj wsc32.lib

4.8 DIALER

The DIALER program dials up a HOST (or BBS) program, connects, and then operates like SIMPLE; in which all serial input is copied to the screen and all keyboard input is sent out the serial port.

     xpp dialer.prg
     alink /subsystem:console dialer.obj wsc32.lib mio32.lib

4.9 SELFTEST

SELFTEST performs basic serial port I/O functionality testing using a loopback adapter. Refer to LOOPBACK.TXT for an explanation of how to make a loopback adapter (without tools!).

     xpp selftest.prg
     alink /subsystem:console selftest.obj wsc32.lib

4.10 EVENT

The EVENT example program is similar to the SIMPLE example program, except that it uses SioEventWait to block (efficiently wait) waiting for incoming serial data.

     xpp event.prg
     alink /subsystem:console event.obj wsc32.lib

5 Revision History

The WSC DLL (WSC32.DLL) is written in ANSI C. All language versions of WSC (C/C++, Delphi, Xbase++, PowerBASIC, FoxPro, dBase, Xbase++, and COBOL) use the same identical DLL.

Version 3.0: August 7, 2000

• The initial release of the Xbase++ version of WSC.

Version 3.1: May 31, 2001.

• RESETDEV Win API call not called (allows USB/serial converters).
• SioPutc and SioPuts return immediately (optionally).
• XYM (XMODEM/YMODEM) allows local upload/download directory to be specified.

Version 3.2: August 27, 2002.

• Added SELFTEST example program.
• Default for RESETDEV is "not called". SioDebug(ASC("R")) to enable.
• SioGetc & SioGets zero unused bits (DataBits 5,6,7).
• Corrected problem with SioBaud(-1, BaudRateCode).
• SioDebug returns -1 if no match.
• Added SioDebug(ASC("W")) toggle SioPuts wait for I/O completion.
• Added code to detect active threads & to close thread handles.
• Added USE_THREADS, so can compile version of WSC32.C without threads.
• Comm handle not saved in SioReset unless it is good.
• SioEvent returns mask that caused the event.
• Added SioInfo(ASC("B")) to get build number.

Version 4.0: January 22, 2004.

• Can now order either with or without source code to the DLLs.
• Added SioSetInteger function to set port specific integer parameters.
• Added SioKeyCode function to pass the key code to the DLL.
• Added SioGetReg function to return the registration string.
• Added "Burst Size" parameter for setting the TX burst size.
• Added ability to signal blocked thread, which was blocked by SioEvent.
  
  
  

Version 4.1: August 12, 2004

• Fixed problem with SioTxClear.
• Added overlapped I/O (for non-Win95) so can signal threads to exit w/o killing them.
• Increased default burst size to 256.
• SioFlow returns WSC_RANGE if cannot recognize parameter.
• Adjusted XModem/YModem timing for faster transfers.
  
  
  

Version 4.2: April 4, 2006.

• SioFlow returns 1 if OK.
• SioSetInteger(Port, 'S', 1) always forces SioEvent to unblock.
• Event mutex code added to EventThread() to prevent race conditions.
• Message box displays error if SioWinError(Buffer, 0) called.
• Major change in overlapped I/O
• Fixed problem: SioEvent returning wrong code.
• SioRxClear clears byte saved by SioUnGet.
• Number of supported ports increased to a maximum of 256.
• Added SioEventChar() and SioEventWait() functions.

Version 4.3: October 8, 2007.

• Fixed problem with SioTxQue returning wrong values.
• Changed SioParms so it checks the range of passed arguments.
• Port is verified in SioEventChar.
• SioStatus returns -1 if port is not functioning (USB/serial port disconnected).