User's Manual

Chapter 6: Configuration
Imager – Advanced Options
170 Warrington Hand-Held Computer User Manual
Max Gain, Max Integration And Max Illumination
These parameters represent internal values used by the 2D imager. The “Auto Exposure” pa-
rameter automatically adjusts the Max Gain, Max Integration and Max Illumination
parameters to produce the best bar code read. Keep in mind that “Auto Exposure” must be
set to on in order for these parameter values to be automatically adjusted.
Double-tapping on any of these parameters displays an associated dialog box in which an al-
lowable range is displayed: Max Gain – 357 to 7920, Max Integration – 0 to 65535,
Max Illumination – 0 to 7.
Decoder Timeout
The decoder is a set of algorithms that examine the image and attempt to find the bar codes,
and then turn the pixels into data that the computer can use—this process takes time. “De-
coder Timeout” limits the amount of time the decoder will spend attempting to decode an
image, and forces it to stop and grab a new image, which will probably be easier to decode.
Adaptive Windowing
“Adaptive Windowing” is an advanced technique used to speed up bar code recognition in
certain applications. This parameter automatically reduces the size of the window to the
user-programmed window size when it successfully decodes (which reduces decode time
the next time it is used), but increases it to the full size window on a failed decode.
Constant Illumination
“Constant Illumination” is used to reduce the intrusiveness of the device’s illumination on
the observer. Instead of the illumination turning on and off every time the device attempts a
decode (2-4 times per second), the illumination stays on from the time the trigger is pulled
until a decode is successful. This feature is useful in low light environments, since it will
also reduce the distraction that the illumination can have on nearby co-workers.
Important: These parameter values should only be changed by qualified Psion
Teklogix personnel.
Note: When decoding multiple bar codes in one image, the value assigned to ‘Decoder
Timeout’ should be increased to 200ms/extra bar code after the first.
Note: This feature assumes that you have reached an understanding about how the device
operates in your application, and that, after a learning period, operators will get
used to using the imager in one particular way. It also assumes that a trained oper-
ator will usually only have near miss scenarios.
Preliminary Draft