Chapter 6. Control Signal Sequence - Sharp ER-A440 Service Manual

CHAPTER 6. CONTROL SIGNAL SEQUENCE

1. Online transmission
1) Half duplex transmission
DCE DTE
SD
RD
RTS
CTS
DSR
DCD
DTR
< 500ms
CI
3) Line connection sequence flow
STARTED BY P.C
NO
NO
FULL DUPLEX ?
LINE ESTABLISHED
DATA
DATA
INITIAL
NO
CI SENSE ?
YES
CI ON ?
DTR ON
NO
DSR ON ?
YES
YES
RTS ON
2) Full duplex transmission
DCE DTE
SD
RD
RTS
CTS
DSR
DCD
< 100ms
DTR
* CI
*Note: In the direct connect mode, same as full duplex control, but
the CI signal is not controlled.
NO
YES
CI SENSE ?
Note : The CI signal can be changed over when
so set in the PGM mode, and effective
at ECR side.
– 11 –
DATA
DATA
< 500ms
ERROR : NO LINE
DTR OFF
NO
YES
TIME OUT ?
30sec
< 100ms