Rockwell Automation 2755 Enhanced Decoder Series B - Manual (Page 106)

7–18 Configuration: Scanner Control, Primary Match Table, Discrete I/O
Publication 2755-833
Read and No-Match Activates the specified output when a valid
read occurs but the bar code data does not match
any entry in the primary match code table.
The read and no-match condition is used to detect
when incorrect labels have been used.
The corresponding output counter increments each
time a read and no-match condition occurs.
No-Read or No-Match Activates the specified output when either a
no-read or a no-match condition occurs. (The bar
code data does not match any entry in the primary
match code table.)
Like the read and no-match condition, this condition
is used to detect incorrect or missing labels.
The corresponding output counter increments each
time a no-read or no-match condition occurs.
Buffer Full The specified output signals that the bar code data
buffer is full and cannot process additional bar code
data. The output turns off when the buffer full
condition is cleared. This is not a pulsed output. The
output will actuate whenever the Buffer Full
condition exists, and turn off when Host
Communications resume.
Often, the decoder can decode data faster than the
host can receive it. Use this condition as an indicator
to control the package rate to keep pace with host
transmissions.
The corresponding output counter increments each
time the buffer full condition occurs.
Buffer Overflow The specified output signals that bar code data has
been lost because of a buffer overflow condition.
The output turns off when the buffer overflow
condition is cleared.
The buffer overflow condition may occur:
•
if host communications is suspended
•
if an XOFF is sent to the decoder via either the
Host or AUX Port
The performance indicator displays 999 until the
buffer overflow condition is cleared.