Worth Data 802 RF user manual Control Keys for Possible Programming, Test For Good Communication

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, WD802Term 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).

Control Keys for Possible Programming

There are some keys on the 802 RF Terminal keypad that when pressed, can transmit special ASCII characters back to the host program. This feature might

be used by a programmer to allow the operator to review transactions. You can use these keys for special program functions, such as scrolling thru data, backing up steps, jumping, finishing a process, etc The keys are as follows:

Key	Code transmitted to Host
UP ARROW key	FS (ASCII 28)
DOWN ARROW key	GS (ASCII 29)
LEFT ARROW key	RS (ASCII 30)
RIGHT ARROW key	US (ASCII 31)
BEGIN key	ETB (ASCII 23)
END key	CAN (ASCII 24)
SEARCH key	VT (ASCII 11)

The STATUS key is reserved to only display the Time and Date.

The Control keys can be used without pressing the ENTER key by using the Control Keys Only Terminal Setup parameter. See Chapter 2; RF System

Setup for details.

6-6