Home -- Software Development -- Activex -- EasyCom -- Description

The EasyCom ActiveX control is a Winsock/Telnet communication component. It is intended for VB and VC++ developers to easily add communication capabilities to their applications. Examples of such communication capabilities might include handling and configuration of remote network equipments and servers, and getting information on such systems.

EasyCom vs. scripting in terminal emulators

There is a couple of advantages about using EasyCom in VB or VC++ rather than using terminal emulators built-in scripting tools. First, you get more control on the running conversation : for instance, when reading, EasyCom affords easily detecting different possible answers from the remote system. Second, you can easily get the characters received and handle and process them as required. See the VB example attached for an example of this.

Services

Each instance of EasyCom handles a connection that can be used for reading and writing. The Read method can wait until one of the strings expected by the calling program is received, and give back control when this (or a time-out) happens.

Errors are handled through error messages that are displayed for a duration that you specify, thus affording working with absolutely no user intervention. But if you made another choice, you can also give user feedback using a “terminal view” window to display the characters exchanged. For even more user control, this window includes a Cancel button that affords prematurely terminating the connection.

Last, you can specify that you are not waiting for any string to arrive from the remote computer and be notified through an event if such a string arrives.

Communication layers supported

EasyCom affords working with several distinct underlying communication layers, but the interface is the same whatever the layer. The difference resides only in the string that you pass to the Open method, and that contains all of the configuration data for the layer :

1. TCP/IP is implemented through the use of the Windows sockets version 2.0. A minimal Telnet emulation is also included. This minimal emulation mainly denies whatever service request is done by the remote computer and hides the Telnet protocol characters exchanged from the component's Read routine.

2. Asynchronous communications are implemented through the use of Mscomm32.ocx, a freely redistributable Microsoft component. The Mscomm32.ocx option makes the assumption that you are connected to a PAD asynchronous equipment using the ITU-TT X3 recommendation (this equipment says "COM" or "ENGAGED" when the conversation is established, and says "LIB" or "CLR" when it is freed).

Legacy X25 and Wincom communication layers

The following layers are not included with the base release of the product but can be provided if required :

3. X25. The software can run on a machine containing a Prima Atlantis X25 board (Windows 95 or Windows NT), or on a client computer (Windows 95) using the Atlantis Gateway.

4. Wincom. Wincom is a Terminal Emulator from Icom informatique, offering TCP/IP, asynchronous and X25 communications. The versions supported by EasyCom are V4.2 (32 bits) and Wincom VT320 (16 bits).

The steps are the following :

Insert the component into your application

In your development environment (any environment that affords using ActiveX full controls), drag'n'drop the component on the form or dialog where it will reside.

Setup the design-time properties

These include the license owner and key information.

Call the methods

EasyCom methods should be called in the following order. First :

1 - Open
2 - Connect

Then as many of these as you need :

3 - Write or WriteNoEcho
3 - Read

Then these :

4 - Disconnect
5 - Close

The Version method may be called at any time to get the component's current version. The interrupt methods works in the X25 or X3 case. Else it does nothing.

Handle the event

The Incoming event may be triggered when the CheckIncoming method is called with a “true” parameter and characters are received from the remote computer.