Interface Configuration and Interpretation

Clear Points

Clears all points from the display grid.

Readings

 

MER (dB)

(Modulation Error Ratio) Provides a single 'figure of merit' for

 

received signal. It is the ratio of 'ideal signal vectors' to 'errored

 

signal vectors' expressed in dB. MER is similar to a

 

signal-to-noise measurement (ref: TR 101 290).

EVM (%)

(Error Vector Magnitude) Closely related to, and can normally

 

be calculated from, MER. It is a ratio of 'errored signal vectors'

 

to maximum signal amplitude expressed as a percentage

 

(ref: TR 101 290 Annex).

BER

(Bit Error Rate) Provides an indication of the Forward Error

 

Correction workload.

TEFs

(Transport Error Flag or TEI transport error indicator) Indicates

 

the Forward Error Correction failure.

Lock

If the QAM interface is able to acquire full lock onto the channel

 

and is receiving the signal correctly, the Lock indicator will

 

light up green. Red indicates that lock cannot be achieved. Gray

 

indicates that a signal is not present.

Settings

 

Update (s)

Allows the period in seconds between samples of the incoming

 

signal to be set.

Persist

Allows the time that the dots persist on the grid display to be set.

Log

 

File

Constellation data can be written to the file identified in this

 

field; data is saved in csv format.

MTM400 MPEG Transport Stream Monitor User Manual

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