Rockwell Automation 2755 Enhanced Decoder Series B - Manual (Page 91)

7–3 Configuration: Scanner Control, Primary Match Table, Discrete I/O
Publication 2755-833
Continuous The decoder continuously attempts to decode every
scan from the scanner. There is no start and stop
control.
The continuous mode of operation is useful during
initial setup to determine the optimum location of
the scanner relative to the bar code labels. (Use a
Symbols Per Package value of 1 for setup.)
The no-read condition does not exist in this mode.
Continuous/Unique The decoder continuously attempts to decode
every scan from the scanner. The decoder discards
valid reads that are identical to the previous valid
read. The decoder does not process data (send to
host or activate appropriate match codes) until a new
valid read is decoded.
A valid package in continuous/unique mode is a
valid read that is different from the previous valid
package.
The no-read condition does not exist in this mode.
Host A start scan command f rom a host device triggers
the decoder to start decoding.
Note: Refer to the section on host communications
for additional information on the start and stop scan
commands.
Package Detect A package detect signal triggers decoding on and
off. The package detect is typically an external
presence sensor or the trigger of a hand-held laser
scanner.
The package detect signals the arrival and departure
of a package.
Internal Timer This mode uses the No-Read Timer as a trigger
source. A set time interval triggers decoding on and
off. The No-Read Timer determines the time
interval.