Panasonic KX-FM131BX / KX-FM131CX Service Manual ▷ View online
Cause 2:
Erroneous detection because of an echo or an echo canceler.
The sea bottom cable or satellite communication path (4 Line Type)
(Echo/Echo Canceler)
The signal from FAX1 reaches FAX2 via stations 1 and 2, but the reflection signal at station 2 also returns via station 1 (echo).
As the distance between station 1 and station 2 is far, the echo returns to FAX 1 at a max of 600 msec after transmission. There
is a possibility that this signal is detected erroneously as the signal from FAX2. For a normal call, there is also a possibility that
the echo of their own voice will make the call difficult to understand. For this reason, each station (station 1 and station 2)
attaches echo cancelers (S1 and S2) for international lines or long distance lines. For the echo canceler, the level of the
transmission signal from FAX 1 is compared with the level of the reception signal from FAX2. When the transmission signal is
larger, S1 is closed while S2 is opened when it is smaller. In other words, for transmission from FAX1, S1 is closed and S2 is
open, so that the echo does not return to FAX1.
As the distance between station 1 and station 2 is far, the echo returns to FAX 1 at a max of 600 msec after transmission. There
is a possibility that this signal is detected erroneously as the signal from FAX2. For a normal call, there is also a possibility that
the echo of their own voice will make the call difficult to understand. For this reason, each station (station 1 and station 2)
attaches echo cancelers (S1 and S2) for international lines or long distance lines. For the echo canceler, the level of the
transmission signal from FAX 1 is compared with the level of the reception signal from FAX2. When the transmission signal is
larger, S1 is closed while S2 is opened when it is smaller. In other words, for transmission from FAX1, S1 is closed and S2 is
open, so that the echo does not return to FAX1.
(Causes and Countermeasures)
(Cause A)
When a training signal is transmitted from FAX1 during the communication procedure at the time of transmission from FAX1 to
FAX2, there is a delay until the echo canceler operates. S1 is closed so that a part of the head of the training signal may drop
out. Normal reception by FAX2 may not be possible, and transmission may not be started.
FAX2, there is a delay until the echo canceler operates. S1 is closed so that a part of the head of the training signal may drop
out. Normal reception by FAX2 may not be possible, and transmission may not be started.
(Countermeasure A)
When the international line mode is ON in the service mode (code No. 521), a dummy signal is attached to the head of the
training signal to prevent this problem. As this is normally ON, it is necessary to reconfirm that this has not become OFF. When
the international mode is switched OFF, the transmission side will try the training signal three times at each speed (9600BPS,
4800BPS and 2400BPS). If NG, it will drop the speed by one rank (fall-back). When the international mode is switched ON,
each speed will be tried only twice. In other words, the slower speed with fewer errors can be accessed more easily. This is
done because the line conditions may deteriorate and the picture may be disturbed more easily during communication for
international lines or long distance communication, even when the training is OK. The default value is ON as preference is given
to clearer pictures rather than speed.
training signal to prevent this problem. As this is normally ON, it is necessary to reconfirm that this has not become OFF. When
the international mode is switched OFF, the transmission side will try the training signal three times at each speed (9600BPS,
4800BPS and 2400BPS). If NG, it will drop the speed by one rank (fall-back). When the international mode is switched ON,
each speed will be tried only twice. In other words, the slower speed with fewer errors can be accessed more easily. This is
done because the line conditions may deteriorate and the picture may be disturbed more easily during communication for
international lines or long distance communication, even when the training is OK. The default value is ON as preference is given
to clearer pictures rather than speed.
(Cause B)
The echo canceler operation stops with a 2100Hz signal. (i.e. S1 and S2 become ON). Accordingly, when FAX1 has executed
automatic reception, a CED signal is output. If this signal is 2100Hz, S1 and S2 will become ON. Then the echo of the DIS
signal output afterwards may be received and FAX1 may execute an erroneous operation, preventing communication from
starting.
automatic reception, a CED signal is output. If this signal is 2100Hz, S1 and S2 will become ON. Then the echo of the DIS
signal output afterwards may be received and FAX1 may execute an erroneous operation, preventing communication from
starting.
(Countermeasure B)
In the service mode, the CED signal frequency is set to 1100 Hz (code No.520), or the time setting between the CED signal and
the DIS signal is set from 75 msec to 500 msec in the service mode (code No.593). This is because the echo canceler operation
stop mode is canceled by an interval of 250 msec or more.
Reduce receiving sensitivity to reduce the effect of RCV echo signal. (Service mode: code No. 598)
the DIS signal is set from 75 msec to 500 msec in the service mode (code No.593). This is because the echo canceler operation
stop mode is canceled by an interval of 250 msec or more.
Reduce receiving sensitivity to reduce the effect of RCV echo signal. (Service mode: code No. 598)
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KX-FM131BX / KX-FM131CX
(Cause C)
This model is FAX1 and the other party is FAX2.
For transmission from this model to FAX2, FAX2 executes automatic reception and transmits a CED signal (2100 Hz) followed
by a DIS signal. As the echo cancelers stops as described in cause B, the echo of the DIS signal returns to FAX2. On the other
hand, this model detects the DIS signal and transmits a DCS signal. In other words, it is possible that the echo of the DIS signal
and the DCS signal transmitted from this model reach FAX2 one after the other. FAX2 detects an error and communication
does not start.
by a DIS signal. As the echo cancelers stops as described in cause B, the echo of the DIS signal returns to FAX2. On the other
hand, this model detects the DIS signal and transmits a DCS signal. In other words, it is possible that the echo of the DIS signal
and the DCS signal transmitted from this model reach FAX2 one after the other. FAX2 detects an error and communication
does not start.
(Countermeasure C)
When the international DIS detection setting is set in the service mode (code No.594), this model does not respond to the first
DIS signal and returns a DCS signal only for the second DIS signal.
DIS signal and returns a DCS signal only for the second DIS signal.
In other words, there is an interval of 250 msec between transmission of the first and second DIS signal so that the echo
cancelers operation recovers. An echo is not generated for the second DIS signal.
cancelers operation recovers. An echo is not generated for the second DIS signal.
Note:
When the other FAX does not respond with a DCS signal after DIS signal transmission, the DIS signal is transmitted three
times for trial.
times for trial.
Summary:
Symptom/Countermeasure Table (Long distance and international communication operations)
SYMPTOM
COUNTERMEASURE
Does not receive in the automatic mode.
a.
If possible, manual transmission should be done from the
transmission side.
transmission side.
b.
If possible, two pauses should be inserted at the end of the auto
dial number on the transmission side.
dial number on the transmission side.
c.
If possible, the Function Selector Switch should be switched to
FAX.
FAX.
Does not transmit.
a.
Confirm the international line mode is ON. (Service mode: code
No. 521)
No. 521)
b.
Set the international DIS detection. (Service mode: code No. 594)
Does not receive.
a.
Set the time between the CED signal and the DIS signal to 500
msec. (Service mode: code No. 593)
msec. (Service mode: code No. 593)
b.
Set the CED frequency to 1100Hz. (Service mode: code No. 520)
6. The unit can copy, but the transmission and reception image are incorrect.
(Long distance or international communication operation)
This symptom highly depends on the transmission and reception capability of the other FAX unit and the line conditions.
The countermeasures for this unit are shown below.
Transmission Operation:
Set the transmitting speed to 4800BPS (service mode: code No. 717) or select the overseas mode.
Reception Operation:
If 80% or more of the reception is incorrect, set the receiving speed to 4800BPS. (Service mode: code No. 718)
·
Refer to 2.4.4. SERVICE FUNCTION TABLE.
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KX-FM131BX / KX-FM131CX
7. How to output the Journal Report:
a. Press the MENU button.
b. Press "#", then " 8 " and " 4 ".
c.
Press the START/COPY/SET button.
d. The report prints out.
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KX-FM131BX / KX-FM131CX
Error code table:
(1) CODE
(2) RESULT
(3) MODE
SYMPTOM
Counter-
measure*
measure*
PRESSED THE STOP KEY
TX & RX
Communication was interrupted by the STOP button.
DOCUMENT JAMMED
TX
The document paper is jammed.
NO DOCUMENT
TX
No document paper.
THE COVER WAS OPENED
TX & RX
The cover is open.
40
NO RESPONSE
TX
Transmission is finished when the T1 TIMER expires.
1
41
COMMUNICATION ERROR
TX
DCN is received after DCS transmission.
2
42
COMMUNICATION ERROR
TX
FTT is received after transmission of a 2400BSP
training signal.
training signal.
3
43
COMMUNICATION ERROR
TX
No response after post message is transmitted three
times.
times.
4
44
COMMUNICATION ERROR
TX
RTN and PIN are received.
5
46
COMMUNICATION ERROR
RX
No response after FTT is transmitted.
6
48
COMMUNICATION ERROR
RX
No post message.
7
49
COMMUNICATION ERROR
RX
RTN is transmitted.
8
50
COMMUNICATION ERROR
RX
PIN is transmitted (to PRI-Q).
8
51
COMMUNICATION ERROR
RX
PIN is transmitted.
8
52
NO RESPONSE
RX
Reception is finished when the T1 TIMER expires.
9
54
ERROR-NOT YOUR UNIT
RX
DCN is received after DIS transmission.
11
58
COMMUNICATION ERROR
RX
DCN is received after FTT transmission.
13
59
ERROR-NOT YOUR UNIT
TX
DCN responds to the post message.
14
65
COMMUNICATION ERROR
TX
DCN is received before DIS reception.
2
65
COMMUNICATION ERROR
RX
Reception is not EOP, EOM PIP, PIN, RTP or RTN.
2
68
COMMUNICATION ERROR
RX
No response at the other party after MCF or CFR is
transmitted.
transmitted.
13
70
ERROR-NOT YOUR UNIT
RX
DCN is received after CFR transmission.
13
72
COMMUNICATION ERROR
RX
Carrier is cut when the image signal is received.
16
75
MEMORY FULL
RX
The document was not received due to memory full.
79
CANCELED
TX
The multistation transmission was rejected by the user.
FF
COMMUNICATION ERROR
TX & RX
Modem error. For the DCN, DCN, etc. abbreviations,
refer to 6.6. MODEM SECTION.
refer to 6.6. MODEM SECTION.
12
TX=TRANSMISSION RX=RECEPTION
Most fax communication problems can be resolved by the following steps.
a. Change the transmit level. (Service code: 596, refer to 2.4.4. SERVICE FUNCTION TABLE.)
b. Change the TX speed/RX speed. (Service code: 717/718, refer to 2.4.4. SERVICE FUNCTION TABLE.)
Note*:
If the problem remains, see the "Countermeasure" flow chart.
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KX-FM131BX / KX-FM131CX
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