![background image](http://html1.mh-extra.com/html/okidata/ml393c-plus/ml393c-plus_service-manual_729925048.webp)
Then the RS232-C interface signals (DSR, CTS, CD and RD) are converted to TTL levels by the line
receiver (Q2) and input to the Master MPU, Slave MPU and MMU. The Master MPU converts the serial
data to parallel data.
The interface signals (DTR, RTS, SSD and TD) output from the Master MPU and Interface LSI are
converted from TTL levels to RS232-C levels by the line driver (Q2) and sent to the serial interface
connector.
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Partner Exchange (BPX) for any updates to this material. (http://bpx.okidata.com)