Rs-232 Interface - Mindeo MD7919 User Manual

3-5 RS-232 interface

Host type:
Standard- The scanner is connected to a standard RS-232 interface.
OPOS/JPOS- The scanner is connected to a POS terminal which may be necessary to install the
OPOS/JPOS driver to be compatible with the manufacturer's scanner. The OPOS/JPOS driver is
provided by the scanner manufacturer; please contact the scanner manufacturer for the instruction.
Flow control:
None-The communication only uses TxD and RxD signals without any hardware or software
handshaking protocol.
RTS/CTS- If the scanner wants to send the barcode data to host computer, it will issue the RTS signal
first, wait for the CTS signal from the host computer, and then perform the normal data communication.
If there is no replied CTS signal from the host computer after the timeout duration, the scanner will
issue an error indication. By setting (Host idle: Low RTS) or (Host idle: High RTS), the scanner can be
set to match the Serial Host RTS line.
XON/XOFF- An XOFF character turns the scanner transmission off until the scanner receives an XON
character.
ACK/NAK- After transmitting data, the scanner expects either an ACK (acknowledge) or NAK (not
acknowledge) response from the host. When a NAK is received, the scanner transmits the same data
again and waits for either an ACK or NAK. After three unsuccessful attempts to send data when NAKs
are received, the 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 scanner when it waits for a
handshaking acknowledgment from the host.
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