Brother FAX 1840C, Service Manual

Page: 364 / 401

App. 4-52 Confidential
WSW50
(SDAA settings)
Selector
No.
Function Setting and Specifications
1
2
Percentage voltage for
interpreting the external
telephone as being hooked up
(based on the network's standard
voltage)
No. 1 2
0 0 : 80%
0 1 : 90%
1 0 : 70%
1 1 : No detection
3
DC mask curve table to be
applied when the line is
connected
0: Apply the initial value specified by local
regulations
1: Apply table DC5 prepared specially
4
AC impedance to be applied
when the line is connected
0: 600
W
termination
1: ZR termination
5
6
Current control to be applied
immediately after connection
of the line
No. 5 6
0 0 : Standard
0 1 : Increase start-up current for
termination
1 0 : Fine current control for termination
1 1 : Not used. (equal to "0, 0")
7
8 AC voltage threshold for
detection of ring
No. 7 8
0 0 : 19 V
0 1 : 11 V
1 0 : 25 V
1 1 : 31 V
NOTE: WSW50 is applicable to models equipped with SDAA circuits.
l Selectors 5 and 6: Current control to be applied immediately after connection of the line
FAX models equipped with an SDAA circuit (on which an NTU chip is mounted) might not be
connected to a broad band line such as an ADSL (Asynchronous Digital Subscriber Line) in a stable
condition. If those models fail to connect to such a line, try to change the current control to be
applied immediately after connection of the line by using selectors 5 and 6.
If selectors 5 and 6 are set to "0" and "1," respectively, the SDAA draws more current, decreasing
the period required to terminate the current control. If they are set to "1" and "0," the SDAA finely
controls precision of the termination current against the voltage to approach nearer to the specified
DC curve that specifies the current vs. voltage characteristics of the network termination. Selecting
either control may solve an unstable connection problem.