Brother DCP-9010CN Service Manual page 556

WSW20 (Overseas communications mode setting)
■
Selector No.
1 EP* tone prefix
Overseas communications
2
mode (Reception)
Overseas communications
3
mode (Transmission)
4 Min. time length from reception
of CFR to start of transmission
5 of video signals
6
At CNG detection, elimination of
chattering noise (Not used.)
7
8 Limitation on CNG detection
- Selector 1: EP tone prefix
Setting this selector to "1" makes the machine transmit a 1,700 Hz echo protection (EP) tone
immediately preceding training in V.29 modulation system to prevent omission of training signals.
Prefixing an EP tone is useful when the machine fails to transmit at the V.29 modem speed and
always has to fall back to 4,800 bps transmission.
The setting made by this selector takes effect only when the Overseas Mode is set to ON.
- Selectors 2 and 3: Overseas communications mode
These selectors should be used if the machine malfunctions in overseas communications.
According to the communications error state, select the signal specifications.
Setting selector 2 to "1" allows the machine to use 1,100 Hz CED signal instead of 2,100 Hz in
receiving operation. This prevents malfunctions resulting from echoes, since the 1,100 Hz signal
does not disable the echo suppressor (ES) while the 2,100 Hz signal does.
Setting selector 3 to "1" allows the machine to ignore a DIS signal sent from the called station once
in sending operation. This operation suppresses echoes since the first DIS signal immediately
follows a 2,100 Hz CED (which disables the ES) so that it is likely to be affected by echoes in the
disabled ES state. However, such a disabled ES state will be removed soon so that the second and
the following DIS signals are not susceptible to data distortion due to echoes. Note that some
models when called may cause error by receiving a self-outputted DIS.
The setting made by selector 3 takes effect only when the Overseas Communications Mode is set to
ON. (The setting made by selector 2 is always effective.)
- Selectors 8: Limitation on CNG detection
If this selector is set to "1," the machine detects a CNG signal according to the condition preset by
selectors 2 and 3 on WSW18 after a line is connected. If it is set to "0," the machine detects a CNG
signal as long as the line is connected.
Function
App.1-23
Setting and Specifications
0: OFF
1: ON
0: 2,100 Hz
1: 1,100 Hz
0: OFF
1: Ignores DIS once.
No. 4 5
0 0: 100 ms
0 1: 200 ms
1 0: 300 ms
1 1: 400 ms
0: OFF
1: ON
* EP: Echo protection
Confidential