Signal-To-Noise Ratio (Snr) − Osd Only; Modulation Mode; Short Term Error Count; Long Term Error Count - Motorola DCT 2000 Installation Manual

B - 1 2 D i a g n o s t i c s
Signal-To-No ise Ratio (SNR) − − − − OSD Only
The SNR displayed on the OSD is a rough estimate of the carrier signal-to-noise ratio. The SNR
displayed is a measure of the QAM cluster variance, which is proportional to the signal-to-noise
ratio.
Analog channels display analog for carrier lock. The SNR display a number for the numeric
value and blank for the ssss value.
A blank display indicates that the digital section of the DCT2000 is still in the initial state. If
this occurs, check diagnostic d07.
Table B-9 lists the SNR indicators for the OSD:
T a b l e B - 9
S N R i n d i c a t o r s − − − − O S D o n l y
ssss value Meaning
Good value
GOOD
Marginal signal level − check the signal
FAIR
Unusable signal
POOR
M o d u l a t i o n M o d e
The modulation mode for analog and digital channels are illustrated in table B-10:
T a b l e B - 1 0
M o d u l a t i o n M o d e
Ch annels

Modulation Mode

Analog
Analog
channels
QAM 64
Digital channels
QAM 256
Sh o rt T e rm Erro r Co u n t
The Short Term Error Count polls the FEC errors (maximum count of 65535) at 5-second
intervals. The Short Term Error Count is cleared after polling.
L o n g T e rm Erro r Co u n t
The Long Term Error Count is the accumulation of the Short Term Error Count (maximum
count of 65535). The Long Term Error Count is cleared every 24 hours.
T u n e d F re q u e n c y
Tuned Frequency (Carrier Definition Frequency + 1.75 MHz) is the actual frequency the tuner is
programmed.
D C T 2 0 0 0 I n s t a l l a t i o n M a n u a l