User's Manual

3-3
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.
The Base Station knows that the data is a retransmission rather than a new data
transmission so it sends a message to the Terminal telling it “I have nothing for
you from the host, go to sleep”.
While in “sleep” mode, the Terminal “wakes” up at specific increasing intervals
and asks “do you have anything for me yet”, waiting for either a “go to sleep”
message or a new data prompt. These are the “wake up” intervals:
Interval Number of times repeated
½ second 5 times
2 seconds 1 time
4 seconds 1 time
8 seconds 1 time
16 seconds indefinitely - until prompt received
After each delays, the Terminal displays:
WAITING FOR HOST PROMPT
Waiting ½ second the first time before asking the base “do you have anything
for me yet?” is OK for most rapid response host programs. If your host program
is slow and doesn’t process your data quickly enough to get a new prompt out to
the terminal within 1/2 second, you need to set a new time by specifying a Host
Response Delay.
Host Response Delay allows you to set a particular delay value that determines
when the terminal will check with the Base for a new prompt. This is valuable
if you know that your program cannot respond for a certain amount of time. If
you know your host program can’t respond for 2 seconds, there is no need for
multiple times after ½ second; that creates unnecessary radio traffic that results
in unnecessary collisions and a decrease in system response time. It also wastes
battery power. Host Response Delay is critical to eliminating contention
between multiple terminals on one Base Station. See Chapter 2; RF System
Setup for details on setting the Host Response Delay.
If a Terminal receives no response at all from a Base Station (no data prompt or
“go to sleep” message), it retransmits its data and waits for a response. If the
Terminal gets no response after 10 re-transmissions, it displays:
TRANSMISSION FAILED
HIT ANY KEY_
Pressing a key on the Terminal starts the re-transmission process over again.
The RF Terminal will try to retransmit its data, displaying the TRANSMISSION
FAILED message after every 10 unsuccessful tries.