Eurotech PCN-1001, Руководство пользователя

Страница: 77 / 118

Know
WinClient PCN-1001 User manual
77
PCN-1001_UserMan_En_4.0
“Time Background” panel
The “Time Background” is an algorithm that can be used after the “Scene background” procedure. It allows you to
dynamically acquire the background in order to manage intense light variations of the detection area or manage
static objects that may be introduced in the detection area after its first acquisition during the installation, all
conditions that may affect the scene background.
WARNING!
The “Time Background” feature has been specifically developed for building installations.
If the PCN-1001 is installed on-board a transportation vehicle it is strongly recommended to disable
the Time background by setting to “0” the value of the “Time bkg” parameter.
This because the time when the door will be open is not predictable. If the acquisition of the
background starts while the door is opening there would be a discrete number of false negatives.
This will happen because the count is disabled during the background acquisition.
The value of the “Time bkg” parameter indicates how many minutes should pass before automatically executing a
new background acquisition; this happens only if during this period of time the image changed a number of pixels
higher than the valued indicated by the “Static Threshold” parameter. The maximum “Static Threshold” value is
19200 pixels.
NOTE:
The “Time Background” algorithm foresees that any person stands in the detection area for less than the
amount of time (in minutes) set by “Time bkg”
Typical values are:
• “Time bkg” = 2-5 minutes (Default set is 0 and means disabled)
• “Static Threshold” = 1500-3500 pixels (Default set is 2500)
The “Time Background” algorithm is enabled giving to “Time bkg” a value higher than 0.
Use the command “timebkg” followed by the number of minutes (unsigned char) in order to set “Time bkg”
Use the command “staticth” followed by the threshold value (number of pixels (int)) in order to set “Static
Threshold”.