Interface - Mindeo ES4600 User Manual

6-4 RS-232 interface
Flow control:
None - The communication only uses TXD and RXD signals without any hardware or software
handshaking protocol.
RTS/CTS – If the embedded scanner wants to send the barcode data to the host, it will assert the
RTS signal first, and then waits for the CTS signal from the host to perform normal data
communication. If CTS is not asserted in Response delay, the embedded scanner will issue an error
indication.
Two-direction flow control - The embedded scanner asserts the RTS signal when it is OK for the
host to transmit. The host asserts CTS when it is OK for the device to transmit.
XON/XOFF – An <XOFF> character turns the embedded scanner's transmission off unit the
embedded scanner receives an <XON> character.
ACK/NAK – After transmitting data, the embedded scanner expects either an <ACK> character
(acknowledge) or <NAK> character response from the host. When a <NAK> character is received,
the embedded scanner transmits the same data again and waits for either an <ACK> character or
<NAK> character. After three unsuccessful attempts to send data when <NAK> characters are
received the embedded scanner issues an error indication and discards the data.
Inter-character delay: This delay is inserted after each data character transmitted.
Response delay: This delay is used for serial communication of the embedded scanner when it waits
for a handshaking acknowledgment form the host.
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