Symbol Technologies LS 400XI Software Handshaking (Contd)

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Parameter Menus
Software Handshaking (Cont’d)
The scanner waits up to the programmable Host Serial Response Time-out to receive an ACK
or NAK. If the scanner does not get a response in this time, it issues an error indication and
discards the data. There are no retries when a time-out occurs.
ACK/NAK
ENQ
When this option is selected, the scanner waits for an ENQ character from the host before
transmitting data. If an ENQ is not received within 2 seconds, the scanner issues an error
indication and discards the data. The host must transmit an ENQ character at least every 2
seconds to prevent transmission errors.
ENQ
ACK/NAK with ENQ
This combines the two previous options.
ACK/NAK with ENQ
XON/XOFF
An XOFF character turns the scanner transmission off until the scanner receives an XON
character. There are two situations for XON/XOFF:
tXOFF is received before the scanner has data to send. When the scanner has data to
send, it then waits for an XON character before transmission. The scanner waits up
to 2 seconds to receive the XON. If the XON is not received within this time, the
scanner issues an error indication and discards the data.