Signaling Encoder and Decoder - Screens and Control Fields

Control Fields for the Signaling Encoder and Decoder

On Time

For the encoder, this field sets the length of time each DTMF tone is on during the sequence.

For the decoder, this measurement column lists the length of time each tone is on during the sequence.

Screens Where Field is Present

SIGNALING ENCODER (Modes: DTMF)

SIGNALING DECODER (Modes: DTMF)

Polarity

This field is used to match the polarity of the encoded signal being analyzed.

This function is helpful to restore the proper data polarity when the transmitter, repeater, or receiver used in your communications system has an odd number of inversions; causing the received data to be inverted when decoded. (This is common when a signal is translated to a lower frequency using an LO whose frequency is higher than the signal’s frequency; or when inverting amplifiers are used.)

Normal Operation

When this field is set to Norm, a logical high (1) is displayed when a positive peak in the received signal is detected. A negative peak displays a logical low (0).

Inverted Operation

When this field is set to Invert, a logical low (0) is displayed when a positive peak in the received signal is detected. A negative peak displays a logical high (1).

Operating Considerations

Inverting amplifiers used in transmitters, receivers, and repeaters can cause an inversion of the modulating digital data. If the decoded signal does not display the expected results, change this field’s setting to see if the signal may be getting inverted before being decoded.

Screens Where Field is Present

SIGNALING DECODER (Modes: AMPS-TACS, NAMP-NTAC)

SIGNALING ENCODER (Modes: AMPS-TACS, NAMP-NTAC)

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Chapter 8

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Agilent Technologies 8935 series e6380a manual On Time, Polarity, Normal Operation, Inverted Operation