User's Manual

A little more in depth…

This RF system’s dialogue is Terminal initiated. The Terminal says, “I’m

here, give me something to do. The Worth Data RF system is different from

other systems in that our RF Terminal does not constantly “listen” for a data

prompt from the host. We decided to use a different approach that would

help to eliminate unnecessary radio traffic, conserve battery power, reduce

the size of the Terminal, and greatly simplify the operation.

Here is how it works:

Each RF Terminal has a unique Terminal ID. When the RF Terminal

powers up, it asks if you want to SIGN ON? Pressing YES at the SIGN

ON? prompt causes the RF Terminal to transmit it’s Terminal ID and a

byte of data indicating to the Base Station that it wants to sign on to the

system.

When you press YES to the SIGN ON prompt on the RF Terminal, the

Terminal will display the following message:

WAITING ON BASE TO ACKNOWLEDGE

This message is normal when first establishing communication and may

occur occasionally during normal operation.

When the Base Station receives a SIGN ON message from a RF Terminal,

the Base Station transmits the SIGN ON information to the host computer.

The host computer application can then do one of two things:

1. If it has something for the Terminal to do, it can send a prompt to the

Base, which in turn transmits it to the Terminal. The RF Terminal

receives the prompt, waits for the operator to enter the requested

data, and then transmits the data back to the Base Station.

2. If the host program does nothing within an allotted time, the

Terminal displays the message:

WAITING ON HOST PROMPT

Lets suppose that a RF Terminal and a Base Station have been processing

data by sending prompts and data back and forth as described in example 1.

The Base Station sends a data prompt to the RF Terminal, the RF Terminal

transmits the operator-entered data back to the Base Station. If the host

program has another prompt for the terminal, the Base sends it out, repeat-

ing the process above.

Suppose the host program does not have a prompt ready to send back to the

Terminal; the Terminal transmits its data to the Base Station but does not

receive a new data prompt. The Terminal then retransmits its data (it thinks

maybe the host didn’t receive it) and waits for a response.

Once the terminal has received a prompt back from the host, the time it took

the host to respond is sent to the Terminal. For all subsequent transmissions,