Rockwell Automation 2755 AtomScan Bar Code Reader - Manual (Page 95)

6–10 Hardware Operation
Publication 2755-6.9
The reader will check the auxiliary port parameter for data when the
reader is about to send a no read message after exiting a read cycle.
The reader will wait up to 20 ms for the first character from the next
reader down the line. If there is no data within 20 ms, the reader will
send a no read message. If there is a character, the reader will wait
for a terminating CR up to 20 ms after every auxiliary character
received and sends the message up the line to the next reader (or to
the host if it is the master scanner). If no CR is received in time, the
reader will send a no read message up to the line to the next reader
(or to the host if it is the master reader).
If you are using more than one label, field separators are necessary to
separate each label and are used by the master reader to count the
number of labels received by the auxiliary port parameter. The
master reader must receive and read at least the number of bar codes
set in Number of Labels. If the reader reads less, the reader will
interpret the auxiliary data it receives as the missing labels and will
add a no read message to the data for each missing label.
The reader connected to the auxiliary port must have the following
settings.
•
Postamble = CR (^M).
•
Postamble is enabled.
•
Multilabel separator and serial trigger character must match the
master setting.
Auxiliary Port Operation
Auxiliary Port Parameters allow you to set communications
parameters between daisy-chained readers or between the reader and
an auxiliary monitor. An auxiliary monitor can be used to configure
the menus, send data to the host, and display data transmissions
originating from the host or reader. The auxiliary port cannot be
used in conjunction with RS-485 or RTS/CTS on the host port.
Note: The Aux Port baud rate should never exceed Host Port baud
rate or auxiliary port data could be lost.