Rockwell Automation 2755 Enhanced Decoder Series B - Manual (Page 92)

7–4 Configuration: Scanner Control, Primary Match Table, Discrete I/O
Publication 2755-833
Figure 7.1 Internal timer trigger
ON
OFF
X Y
X = Y = No-Read Timer value (in milliseconds)
Minimum value = 10 msec
Maximum value = 9999 msec
➀
Resolution = 5 msec
A no-read occurs if the timer expires before a valid
package occurs.
The Internal Timer decode mode is useful during
initial setup to simulate the package detect signal.
Note: When Scanner B is operating independently from Scanner A,
its decode mode is always either Package Detect or Host.
No-Read Timer
Field Type Options
Edit 10 through 9999 or 0
Specifies the length of time the decoder will try to decode a label
when triggered by a host command or package detector. The timer
starts when the decoder is triggered. If a valid package does not
occur within the specified time (Symbols/Package setting is not
satisfied), a no-read occurs.
The default of 0 disables the timer. To set the timer, enter a number
between 10 and 9999.
➀ Select a value that allows the decoder enough
time to read an entire package or a no-read will occur.
Note: When the decode mode is set to internal timer, the no-read
timer functions as a trigger source. The trigger remains on until the
no-read timer expires. See Internal Timer under Decode Mode.
➀ ATTENTION: Set output durations in multiples of 5 milliseconds. Actual output will have a worst-case precision
of +0 to –5 milliseconds, varying with the timing of the output. Durations that are not set in multiples of 5
milliseconds will be rounded up to the nearest multiple of 5 and function within the same +0 to –5 millisecond
precision.
For example, a setting of 25 milliseconds will result in a duration of from 20 to 25 milliseconds. A setting of 23
milliseconds will result in the same duration range.