Programming Reference Guide

Programming Reference Guide 243
Chapter 5
Message Formatting
Message Formatting
A message from the Host to the base must follow these rules:
• If Address stamping options or address delimiter are
enabled on the base, the Host
replay must have address field and delimiter too. Otherwise the message will be
ignored. Address delimiter is present only when address stamping is enabled.
• Address stamping is necessary to correctly route
the message to the scanner, especially
when more than one handheld is linked to the same base. Address stamping could be
disabled if the system is in point to point configuration. If address stamping is not
enabled, the messages are addressed to the first handheld linked to the base.
• The maximum character length for
messages is 48.
• Messages end with “CR” 0x0D ASCII character. The CR character cannot be con-
tained in the middle.
• Messages cannot start with '$' or # because these
are reserved for Service mode com-
mand
• Base station can receive host message only if
Host Commands Obey/Ignore is set to
Ignore.
• Message could be sent to the HH in response
to a Label when “Transmit mode” require
Ack from Host (see transmit mode parameter) or at any time. When messages are sent
not in response to a label must start with DC2 0x12 ASCII character and could be sent
in any transmit mode setting.
• Message could be sent to all HH linked to bas
e by using a Multicast message:
“00 00 00 00 2A AA”
• In order to receive a message, handhelds must not be in sleep state.
The format of the ACK from Host message (used for transmiss
ion mode 02) is:
[Scanner_Addr] [Scanner_Addr_delimiter] MESSAGE <CR>
The format of a generic message From Host to HH is:
[Scanner_Addr] [Scanner_Addr_delimiter] DC2 MESSAGE <CR>
where DC2 is ASCII 0x12 (^R) character.
[Items in square brackets are optional.]
• If you want to control the Scanner's beeper from t
he host, you will also probably want
to disable the good transmission beep that is emitted when the code is received from
the cradle. (See "W
ireless Beeper Features" on page 192).
The message field can store plain text and escape sequences.