User's Manual

6-8
host is still functioning. By SIGNing OUT and SIGNing back ON, the operator
should receive a message that there is nothing to do. It is also a good idea for the
host to keep track of elapsed time that a terminal has not had a message sent out to
it. The host should then send a message periodically to re-assure the operator
(remember to ask him to press ENTER) that instruction is coming or tell him to
see his supervisor for re-assignment (or whatever makes sense for your
application).
Ideally, if the operator is leaving the area (to go to lunch or move to another
building) before he is out of range of the network, he should SIGN OUT, then
SIGN ON upon his return.
Prior to RF Terminal version 9075, all terminals signed on using ASCII 15. As
of RF Terminal version 9075, in order to distinguish between 4 line and 6 line
display terminals, an additional SIGN ON character was added. A 6 line display
terminal configured as a 6 line display (see Installation and Setup for LCD
DISPLAY MODE) now sends ASCII 22 as its SIGN ON character. A 6 line
display terminal configured as a 4 line display will transmit the ASCII 15
character for SIGN ON. All 4 line display terminals regardless of their version,
will SIGN ON using the ASCII 15 character.
SIGN OUT
When a RF Terminal is powered down manually or the user presses the F1 key
to exit data entry mode to go to one of the other modes (SETUP or ONE WAY),
the host receives the following SIGN OUT message:
Byte position Function Possible values
1 RF Terminal ID 0-F
2+ SIGN OUT SO (ASCII 14)
Last Termination of message CR (ASCII 13)
Base Station Error Feedback
The following are four different unexpected feedbacks that the Base Station can
send back to your program: (Be sure to look for each of them to be sure your
program doesn’t blow up at an unexpected time.)
Addressing a Terminal not SIGNed ON
If the host attempts to send a message to a terminal that is not SIGNed ON, the
Base Station sends back the following message to the host computer:
Byte position Function Possible values
1 RF Terminal ID 0-F
2+ Terminal NOT Signed In DC1(ASCII 17)
Last Termination of message CR (ASCII 13)