DHY-03 User Handbook
13
Acoustic Cancellation Enable – SW6 {OFF}
When switch SW6 is enabled the DHY-03 performs a local acoustic cancellation on the
incoming signal from the audio input. This is required when this signal contains elements of
the signal sent to the output (e.g. in a bingo hall when the output goes to the speakers and
the input is driven from a microphone that can pick up the speaker output.)
Network Cancellation Enable – SW7 {ON}
When switch SW7 is enabled (on) the DHY-03 will perform the echo cancellation routine on
the incoming signal from the telephone line. This would be the normal operational setting,
but it may be disabled for special circumstances.
Country Set on Power Up – SW8 {OFF}
SW8 is only read on power-up and needs to be on to set the specific country code to be
used for the unit (set on remaining switches - see Table 2-1 on page 19). After power up the
switches should be returned to their normal position, otherwise the unit may fail to work
correctly. The country code can also be changed via the serial port, but in either case when
the country setting is altered, any calibration parameters are discarded as they will most
likely now be incorrect. These parameters include tuned hybrid impedance settings
& coefficients and default cancellation calculation coefficients.
Remotes
The remote port allows the user to control the line hold circuit from a mixing desk or other
remote device and also outputs opto-isolated outputs to indicate the line hold status and
the DTMF detect function. See chapter 4 for connection details.
RS232 Serial Port
The serial port allows the user to remote control the DHY-03 connection, including the
ability to dial out using Tone Dialling. This port is also used to adjust the operational
parameters and upload new firmware. Full details are given in chapter 3.
C
ONFIGUR
A
TION & C
ONTR
OLS
CONFIGURATION & CONTROLS
Remotes
RS232 Serial Port
Figure 2-4 : Rear Panel Controls.
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