18
5. Handshaking
Table 8. Handshaking
The DTR signal is always set to SPACE while X-on/X-off
handshaking is selected.
X-on/X-off characters will not be transmitted from TXD
while DTR handshaking is selected (TXD signal is always set
to MARK).
Note
Operation is not guaranteed when using the current loop
mode at rates over 1,200 BPS.
RS-232D
Control Loop
Using DTR protocol
The two signal
conditions at pin No.11
and pin No.20 are as
follows;
MARK
data entry is
disabled
SPACE
data entry is
enabled
The impedance
between pin No. 17
and pin No. 24 is as
follows;
LOW(MARK)
data
entry is disabled
High(SPACE)
data
entry is enabled
Using X-ON/X-OFF
protocol
Data transmitted from
pin No.2 is controlled
as follows;
X-ON<11>
H
data
entry is enabled
X-OFF<13>
H
data
entry is disabled
Data transmitted by
the change of the
impedance between
pin No. 17 and pin No.
24 is controlled as
follows;
X-ON<11>
H
data
entry is enabled
X-OFF<13>
H
data
entry is disabled