Worth Data 5000 TriCoder s Manuel du propriétaire télécharger pdf (Page 80)

Test For Good Communication

• Implement an event handler for OnTermSignIn that causes a beep or displays a message when called. If

communication between the host PC and the terminal is good, your event handler will fire when your

program is running and you sign in a terminal on your network.

Terminal Tracking

• Since you get only one set of event handlers, you will need some scheme for keeping track of where

each terminal (up to 1000) is in its transaction sequence. Remember, WD7802Term will give you a

unique ID number for each Terminal that signs in and that number is “locked” to that Terminal until it

signs out. One possible solution is to use a "state" variable for each terminal (perhaps stored in an array).

Test the state variable to determine the next prompt for any given terminal. See the samples for more

ideas.

• It is very important to keep track of "login status" for each terminal. Every SignOut event should have

an associated SignIn event and a given terminal should not be allowed to SignIn twice without and an

intervening SignOut. Multiple SignIns from one terminal without appropriate SignOuts indicate either:

1. A terminal going out of range and having its power cycled before returning within range OR

2. Two (or more) terminals using the same IP address (terminal ID conflict).

Real-Time vs. Batch Mode Operation

It is possible to build a system that operates in only Real-Time mode or only in Batch Mode. It is also

possible to build a system that can operate in either mode.

Real-Time and Batch mode can be combined since sending a batch program is just like sending a prompt,

and receiving data from a batch program is just like receiving data from a prompt response. It is also

possible to create a program that allows the Terminal operator to decide and choose whether to operate in

Batch mode or Real-time mode.

It is important to understand that operating in Batch mode requires some identification scheme for each data

field. This is because there is no way to maintain or guarantee a 1:1 prompt-data relationship when receiving

Batch data, as opposed to receiving Real-time data. The easiest way to do this is to assign data prefixes for

each data collection statement in the Batch program and have your application use the prefixes to sort out

what each piece of data is for.

Concepts – WD7802Term ActiveX

Drop-in components are tools that are added to your programming environment "tool kit". Only the ActiveX

variety are widely compatible with almost all development environments. When you use drop-in

components in your program you will follow the standard object-oriented programming paradigm that uses

properties, methods, and events to implement the functionality of the drop-in component.

Properties are the various configuration variables used by the drop-in component. An example of a

property is the ServerActive setting.

Methods are function calls used to issue commands and access features of the drop-in component. An

example of a method is sending an Input command to the terminal.

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Worth Data 5000 TriCoder s Manuel du propriétaire Page 80