7700 MultiFrame Manual
7700ADA7-EQ Equalizing Analog Video Distribution Amplifier
Revision
1.2
Page - 5
4. STATUS
LEDS
The 7700ADA7-EQ has seven LED Status indicators on the front card edge to show operational status of
the card at a glance. Figure 6-1 shows the location of the LEDs.
Two large LEDs on the front of the board indicate the general health of the module:
LOCAL FAULT:
This Red LED indicates poor module health and will be On during the absence of a
valid input signal, or if a local input power fault exists (i.e.: a blown fuse). The
LOCAL FAULT indication can also be reported to the frame through the FRAME
STATUS jumper.
MODULE OK:
This Green LED indicates good module health. It will be On when a valid input
signal is present, and the board power is good.
There are five small LEDs that indicate the status of the input video.
SD/HD Video Presence Indicators:
The width of sync is measured to determine if video is present and if it is NTSC/PAL-B or if it is analog
high definition video. If sync is approximately 4.7µsec wide, the green
SD PRES
LED is illuminated. If
sync is approximately 0.6µsec wide, the green
HD PRES
LED is illuminated. If neither sync size is
present, both LEDs are turned off.
This technique will also successfully detect HD signals with bi-level sync generated by Evertz DACs for
applications with computer monitors. Other manufacturer’s DACs may not have the same sync size so
the detection may not work with these signals.
Sync High/Low Indicators:
The sync level of the processed video is measured to determine if its amplitude is approximately
correct. If sync is below 270mV then the amber
SYNC LOW
LED is turned on and if sync is above
320mV then the amber
SYNC HIGH
LED is turned on. This measurement takes place AFTER all of
the card processing. This means that if the card is not calibrated properly, the indicators will not
represent the proper state of the video. This includes improper setting of restored DC level, poorly
equalized video and wrong gain settings.
"
These indicators will NOT indicate properly when the input video is AC coupled
and the DC restore clamp is turned off.
Video High Indicator:
The level of the processed video is measured to determine if its amplitude is approaching the 100%
level. If in one field, the video is ever above 700mV then the amber
VIDEO HIGH
LED is turned on for
a short duration. If the video is consistently too "hot", then the light will always be on. This
measurement takes place AFTER all of the card processing. This means that if the card is not
calibrated properly, the indicator will not represent the proper state of the video. This includes improper
setting of restored DC level, poorly equalized video and wrong gain settings.
"
These indicators will NOT indicate properly when the input video is AC coupled
and the DC restore clamp is turned off.