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CHAPTER 19 DIAGNOSTIC INFORMATION
ATSC Receiver Blades
If an ATSC channel is not coming through, check the diagnostic information for the ATSC blade.
1. Click the Blades tab.
2. Locate the ATSC card and click the down-arrow under Details.
3. Verify the following:
RSSI – Received Signal Strength Indicator
Low RSSI indicates the antenna is not tuned correctly. In the event of a low RSSI, SMARTBOX may not
be able to lock to a service. -75 is the lowest value for which the software will assign a service to a tuner.
Tuner Lock and Demod Lock
Both Tuner and Demod must be locked to receive data from a station.
Demod SNR–Demod Signal-to-Noise Ratio
This value indicates a signal-to-noise ratio for the individual tuner. Higher is better. Above 20 is good.
RS Uncorrected– Reed-Solomon Errors
When the signal is weak, there may be a lot of RS errors. Each error causes a drop of at least one packet of
data and usually results in deteriorated picture or sound. Zero is good; more than a few errors indicates a problem.
ATSC Receiver Blade Input Specifications
ATSC Receiver Blade Input Power Range
The signal input into the ATSC Receiver Blade should fall into the range below. Any signal power outside of this
range may result in intermittent performance. Be sure to note the measurement being used.
Component
dBm dBmV
High -9.5 dBm +39.25 dBmV
Low -83.5 dBm -34.75 dBmV
ATSC Receiver Blade Signal Quality
1) Services with an SNR less than 20 for an incoming ATSC signal is likely to have some RS uncorrected errors,
which indicate that issues such as pixelation, freezing, or dropped services may occur.
2) If the RSSI is less than -75 during the scan, the services on that RF channel will not be listed as configurable
services. The RF channel will also not be listed if there are too many RS Uncorrected errors. As the scan is only a
few seconds per channel, there should be zero RS Uncorrected errors. The lower the SNR the more the number of
RS Uncorrected Errors there will be.
Satellite Receiver Blades
CER – Character Error Rate
A high CER number (in the thousands) indicates there is a problem with the satellite stream coming into
SMARTBOX - check the satellite feeds. A small number is not a problem. An increasing number indicates a current
signal issue. You can reset the CER counter on the satellite receiver blades by clicking the Reset all CER Counters
on the Blades tab to verify if the counter is increasing. This will bring the counters back to 0. If a tuner loses lock,
the CER will be reset.
SNR – Signal to Noise Ratio
A high SNR is a good indication. For satellite receiver blades, an SNR greater than 12 is desirable.
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