Grass Valley DEC-1023 - Manual (Page 25)

GUIDE TO INSTALLATION AND OPERATION
DEC-1023 | 21
The controls for all of these error types are identical (see figure 3.14), except for the threshold range
available. Each set of controls contains these elements:
Enable: a checkbox to enable the alarm associated with this parameter
Threshold: a threshold value for detection of an error. The error will be detected when the measured
parameter falls above (or below, depending on the nature of the parameter) the indicated threshold value. In
most cases this is a slider with data entry box.
Below the THRESHOLD slider are found controls for configuring the conditions under which a detected error
is flagged and reported. These conditions are set independently for each error type::
• ERROR DURATION: the length of time during which a parameter is allowed to be out-of-tolerance
without being identified as an error. This is useful for situations such as a hard switch or patch of a
video signal where there is a discontinuity in the signal which the user has deliberately caused and
does not need to be flagged as an error. If a parameter is continuously out of tolerance for the
specified duration, then an error is considered to have been detected. However, this error will not be
flagged (causing the status LED to change color and an error message to be sent out on the frame’s
interface) until the OCCURRENCE / DETECTION WINDOW conditions have been satisfied.
(Range: 0 to 90 seconds)
• OCCURRENCE: the number of times that a detected error is allowed to occur in a specified
DETECTION WINDOW before an error flag is set, and the error is reported (status LED changes color,
and message sent on the interface)
(Range: 1 to 16)
• INTERVAL: the time duration during which errors are counted to determine if the error flag should be
set. This is a moving window, e.g. the previous 2 minutes, and only errors falling within that window are
counted.
(Range: 1 min to 24 hours)
LOCKS tab: allows the user to lock the alarm settings for pairs of audio channels, e.g. 1& 2, 3&4.
HELP tab: gives the user basic information on the different audio parameters
.
• Use the pulldown to select the error type
3.5.7 Blanking
This panel provides control over VBI data handling.
VBI: PROCESS, PASS, BLANK, LINE BY LINE: select whether the overall VBI data field will be processed,
will pass or be blanked. If Line by Line is selected, use the right-side panel to set each line individually.
LINE BY LINE: Available when Line by Line is checked in the previous section. Radio buttons allow the
selection of conditions for each line of the VBI data field.