RS-232C Options (Continued)
Hardware Handshaking
If RTS/CTS handshaking is selected, scan data is transmitted with the
following sequence: (Note that the DTR signal is hard wired active.)
The scanner reads the CTS line for activity. If CTS is asserted, the scanner
•
will wait up to two seconds for the host to negate the CTS line. If, after
one second the CTS line is still asserted, the scanner will sound a transmit
error and any scanned data will be lost.
When the CTS line is negated, the scanner asserts the RTS line and waits
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for two seconds for the host to assert CTS. When the host asserts CTS,
data is transmitted.
When data transmission is complete, the scanner will negate RTS after
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sending the last character.
The host should respond by negating CTS. The scanner will check for a
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negated CTS upon the next transmission of data.
During the transmission of data, the CTS line should be asserted.
If the above communications sequence should fail, the scanner will issue
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a transmit error. In this case, the data is lost and must be rescanned.
Programming
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