Software Handshaking - Motorola LS3408-FZ20005 Product Reference Manual

RS-232 Interface 6 - 13

Software Handshaking

This parameter offers control of the data transmission process in addition to, or instead of, that offered by hardware
handshaking. There are five options.
If software handshaking and hardware handshaking are both enabled, hardware handshaking takes precedence.
None
Select this option to transmit data immediately. No response is expected from host.
*
None
ACK/NAK
If you select this option, after transmitting data, the scanner expects either an ACK or NAK response from the host.
When it receives a NAK, the scanner transmits the same data again and waits for either an ACK or NAK. After
three unsuccessful attempts to send data after receiving NAKs, the scanner issues an error indication and discards
the data.
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
If you select this option, the scanner waits for an ENQ character from the host before transmitting data. If the
scanner does not receive an ENQ within the Host Serial Response Time-out, the scanner issues an error indication
and discards the data. The host must transmit an ENQ character at least every Host Serial Response Time-out to
prevent transmission errors.
ENQ