Samsung ERV RHF025EE Service Manual page 98

Circuit Descriptions
3. Communication (485 Communication) Part
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■ Communication (485 Communication) Part Description
1. Faulty Connection Prevention RELAY: When 220V power is supplied to power source link, 12V voltage is provided to RELAY, so
as to connect communication link. (Protect circulation in case of fault power source link or communication link.
2. SNUBBER Circulation: NOISE of over 5V is eliminated through SAC5.0 DIODE.
3. 485 IC (Line Driver/Reeceiver)
● HIGH / LOW is determined through voltage gap between the two electrodes of A and B.
: A-B>200mV : HIGH, B-A>200mV : LOW
● DATA is received and prepared with "R" PORT. When sending the DATA, HIGH is input at ENABLE.
4. EXCLUSIVE GATE
Non-polar communication realization element to change signal LEVEL with utilizing INVERSE when connections is switched.
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