Sharp FO-475TH Externally connected TEL OFF Hook detection circuit section, CI detection circuit

UX-258TH

FO-475TH

5.Externally connected TEL OFF HOOK detection circuit section

•The circuit current detection is turned on together with OFF HOOK of main body or OFF HOOK of externally connected TEL. ON of CML OFF is judged as OFF HOOK of externally connected TEL.

6.CI detection circuit

•CI is detected by the photocoupler which is integrated in series in the primary side TEL circuit well proven in the existing unit.

7.Signal/DTMF transmission level & receiving level

•Signal transmission level setting: ATT 7 dB Circuit output: 7 dBm.

• DTMF transmission level setting: HF -6.0 dBm	LF -7.0 dBm
Thus, set the level.

•Attenuation in the LIU section of the receiving level is degigned at -6 dBm. (The modem and circuit error are not included.)

7.Signal selection

The following signals are used to control the transmission line of TEL/ FAX signal. For details, refer to the signal selector matrix table.

[Control signals from output port]

Signal Name			Description
CML	Line connecting relay and DP generating relay
(The circuit is located	H: Line make
in the TEL/LIU PWB.)	L: Line break
SP MUTE	Speaker tone mute control signal
(The circuit is located H: Muting (Power down mode)
in the TEL/LIU PWB.) L: Muting cancel (Normal operation)
	Handset reception mute control signal
TEL MUTE	H: Muting
	L: Muting cancel
	Speaker volume control signal,
		VOL A VOL B VOL C matrix
	OUTPUT	VOL A		VOL B	VOL C	OH-HOOK
						Receiving
	X0	L		L	L	—
	X1	H		L	L	—
	X2	L		H	L	HIGH
	X3	H		H	L	MIDDLE1
VOL A	X4	L		L	H	MIDDLE2
VOL B	X5	H		L	H	MIDDLE3
VOL C	X6	L		H	H	LOW
(The circuit is located	X7	H		H	H	—
in the control PWB.)
	OUTPUT	RINGER		BUZZER	DTMF	ICM/OGM
	X0	—		—	—	HIGH
	X1	HIGH		—	—	MIDDLE1
	X2	—		—	—	MIDDLE2
	X3	MIDDLE		—	HIGH	MIDDLE3
	X4	—		FIXED	MIDDLE1	—
	X5	—		—	MIDDLE2	LOW
	X6	—		—	MIDDLE3	—
	X7	LOW		—	LOW	—

•The volume settings of ON-HOOK receiving, DTMF and ICM/OGM must be performed to- gether. (The setting of RINGER must be per- formed separately.)

TXCONT	TXOUT mute signal
	L: Signal sending, when transmitting
(The circuit is located
	H: During reception, transmission mute,
in the control PWB.)
	(during standby)
GAIN-C	Reception gain switching signal
(The circuit is located	H: When connected to line, 1: 1 gain
in the control PWB.)	L: When not connected to line, HIGH gain
BZCONT	Speaker output signal switching
(The circuit is located	H: Buzzer signal output
in the control PWB.)	L: When monitoring line signal

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