Toshiba DP120F, Руководство по обслуживанию

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DP120F/DP125F Circuit Description 7-80 March 2000 © TOSHIBA TEC
EU/AU/ASIA/HK models
Fig. 7-4-4
07-04-01E
Signal Name Type Active Description Destination
CML1 O H Line 1 CML Relay Control Signal RLY3, IC3
ATT3DB1 O H Line 1 Attenuator Control Signal IC3
RLADJ11,2 O H Line 1 Return Loss Adjust Signal 1, 2 IC5, IC7
The line path switching control circuit consists of the relays (RLY3, RLY4) and analog switch
(IC3, IC5) on the NCU PBA, the I/OP-1 GA (IC7) on the Main PBA, and other peripheral de-
vices. It changes the path for facsimile send/receive signals and connects it to each control
circuit.
The CML relay (RLY3) is switched according to the CML1 signal output from the I/OP-1 GA on
the Main PBA. When the CML1 signal goes HIGH, Q4 turns on to turn on the CML relay.
The relay (RLY4) is switched according to the RLADJ11 and RLADJ12 signals. When the
RLADJ11 and RLADJ12 signals goes Low, Q9 turns on to the relay turn on.
The analog switch (IC3) is switched according to the CML1 signal and ATT3DB1 signal. When
the CML1 signal or ATT3DB1 signal goes HIGH, the analog switch turns on.
The analog switch (IC5) is switched according to the RLADJ11 and RLADJ12 signals.
The analog switch is switched according to the states of the RLADJ11 and RLADJ12 signals.
Turning on the CML relay and analog switch allows the MODEM to be connected to the line.