Frame Manual
500ADA-EQ-L Equalizing Analog Video Distribution Amplifier
Revision
1.2
500ADA-EQ-L - 5
4. STATUS
LEDS
The 500ADA-EQ-L 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 manufacturers 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.