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770/GS/GJ-BA-defsi-0023

For data communication with a software handshake, “XON“ must be sent by a device

when it is turned on in order to enable another on-line device to exchange data.

Sequence:

Balance

Receiving device

-------- byte --------->

<---------<XOFF>---------

-------- byte --------->

(Once <XOFF> has been transmitted, a maximum

-------- byte --------->

of 14 bytes can still be received.)

: :

: Pause :

: :

<---------<XON>----------

-------- byte --------->

Transmitting device:

The importance of handshake control for data transmission becomes especially

apparent

- when the continuous automatic data output parameter is defined;

- when data output is controlled by application programs.

Once <XOFF> has been received, it prevents further transmission of characters. When

<XON> is received, it re-enables the transmitting device to send data. The transmitting

device is always enabled for sending data after it has been switched on.

If data transmission is interrupted by the control line (CTS) or the command <XOFF>

while a data block is being output from an application program (only for printing a

section of text with several lines of data), the readout will be blocked into the display at

the same time.

Data output will be blocked until the interface receives an enabling signal.

KERN 770-14 User Manual

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