5. Handshaking

Table 8. Handshaking

 

US-232D

Control Loop

 

 

 

 

Using DTR protocol

The two signal

The

impedance

 

conditions at pm No.

between pin No. 17

 

11 and pin No. 20 are

and pin No. 24 is as

 

as follows;

follows;

 

MARK-data entry is

LOW(MARK)-data

 

disabled

entry

is disabled

 

SPACE-data entry is

High(SPACE)-data

 

enabled

entry

is enabled

 

 

 

 

Using X-ON/X-OFF

Data transmitted from

Data

transmitted by

protocol

pin No. 2 is controller

the change of the

 

as follows;

impedance between

 

X - O N < l l > H - d a t a

pin No. 17 and pin

 

entry is enabled

No. 24 is controlled as

 

X - 0 F F < 1 3 > H - d a t a

follows;

 

entry is disabled

X - O N < l l > H - d a t a

 

 

entry

is enabled

 

 

X-OFF<13>H-data

 

 

entry

is disabled

 

 

 

 

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.

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