Symbol MiniScan MS XX07 Series, Integration Manual

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MS XX07 Series Integration Guide
Hardware Handshaking
The data interface consists of an RS-232 port designed to operate either with or without the
hardware handshaking lines,
Request to Send ( RTS ) , and Clear to Send ( CTS ) .
If Standard RTS/CTS handshaking is not selected, scan data is transmitted as it becomes
available. Select Standard RTS/CTS handshaking to transmit scan data according to the
following sequence:
• The scanner reads the CTS line for activity. If CTS is asserted, the scanner waits
up to the Host Serial Response Time-out for the host to negate the CTS line. If,
after the Host Serial Response Time-out (default), the CTS line is still asserted, the
scanner sounds a transmit error and discards any scanned data.
• When the CTS line is negated, the scanner asserts the RTS line and waits up to
the Host Serial Response Time-out for the host to assert CTS. When the host
asserts CTS, the scanner transmits the data. If, after the Host Serial Response
Time-out (default), the CTS line is not asserted, the scanner sounds a transmit
error, and discards the data.
• When data transmission is complete, the scanner negates RTS 10 msec after
sending the last character.
• The host responds by negating CTS. The scanner checks for a negated CTS upon
the next transmission of data.
During data transmission, the CTS line should be asserted. If CTS is deasserted for more
than 50 ms between characters, the transmission is aborted, the scanner sounds a
transmission error, and the data is discarded.
If this communications sequence fails, the scanner issues an error indication. In this case,
the data is lost and must be rescanned.
If Hardware Handshaking and Software Handshaking are both enabled, Hardware
Handshaking takes precedence.
Note: The DTR signal is jumpered to the active state.