DTMF Troubleshooting

Possible Setup Issues

If the DTMF symbols are not captured correctly, the it is possible that the Trigger Arm setting of the measurement is Continuous and the gate time is small. It is recommended to set the trigger arm state to single and retry measurement.

If more than 16 DTMF symbols are transmitted, the DTMF measurement only provides results for the first 16 DTMF symbols detected.

If the input signal is not present or is less than the minimum required input signal, then the integrity is set to "Under Range" and all other results of the measurement are 9.91E+37.

If the input signal overdrives the receiver or is clipped by the receiver, then the integrity is set to "Over Range" and all other results of the measurement are 9.91E+37.

Interpreting Integrity Indicator values

See Integrity Indicator

• If Over Range (5) is returned, it indicates that the input power has exceeded test set' s internal sampler maximum value by at least 6 dB during some part of the sampling or the input power has exceeded the calibrated range of the test set' s power detector for the expected power setting.
• If Under Range (6) is returned, it indicates that the measured input power is more than 20 dB below the expected input power level. Under range also indicates that the input power is more than 2 dB below the calibrated range of the test set' s power detector (-30 dBm). If the expected input power setting is correctly set for signal level into the test set, an under range condition can still occur if the receiver has not been tuned to the signal' s frequency.
• If Burst Not Found (25) is returned, it indicates that no valid DTMF character is measured.
• If the measurement has several errors, the error that has the highest priority is indicated.

Related Topics

DTMF Measurement Description

Measuring DTMF

Programming a DTMF Measurement