Owner`s manual

Byte position Function Possible values
1 SIGN ON SYN (ASCII 22) if 15 line
display configured as a 15 line
display.
SI (ASCII 15) if 15 line display
terminal configured as 15 line
display.
DC4 (ASCII 20) if 15 line
display configured as a 15 line
display.
Last Termination
of message
CR (ASCII 13)
After a terminal SIGNS ON, the host should be prepared to acknowledge the SIGN ON and give the
terminal instructions, such as:
Standby for Assignment, Press ENTER to acknowledge
Nothing to do, Press ENTER and See Supervisor
Pick Item 1234
If there is something for the Terminal to do, the host should send instruction to the terminal (as in “Pick Item
1234” above). If there is nothing to do at the time of SIGN ON, the host should acknowledge the SIGN ON
and tell the terminal to Stand By or See Supervisor (see lines 1 and 2 above). You will notice that in lines 1
& 2 above, there is a request for the operator to press the ENTER key. This is required for the message to be
a valid command - remember that all messages must end with a request for data input. The host should then
expect a response from the terminal of DATA (none if only pressing ENTER key) + CR.
SIGN ON is a good way for the terminal operator who has not received instruction from the host for several
minutes to determine if he is still connected and if the 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.
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 SIGN OUT SO (ASCII 14)
Last Termination of
message
CR (ASCII 13)
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