Hardware Handshaking; Standard Rts/Cts - Symbol Cyclone M2000 Series Product Reference Manual

Cyclone

Hardware Handshaking

The host exchanges data with the scanner via a serial port, either with or without the
hardware handshaking lines, Request to Send (RTS), and Clear to Send (CTS).

Standard RTS/CTS

If Standard RTS/CTS handshaking is selected, scanned data is transmitted according to
the following sequence:
• The CTS line must initially be deasserted by the host. If the scanner detects that
CTS is asserted (indicating that the host may still be receiving a previous
transmission), the scanner waits up to 2 seconds for the host to deassert the CTS
line. If, after 2 seconds (default), the CTS line is still asserted, the scanner sounds
a transmit error and any scanned data is lost.
• When the CTS line is deasserted, the scanner asserts the RTS line and waits up
to 2 seconds for the host to assert CTS. When the host asserts CTS, the scanner
transmits the data. If, after 2 seconds (default), the CTS line is not asserted, the
scanner sounds a transmit error and discards the data.
• When data transmission is complete, the scanner deasserts RTS 10 msec after
sending the last character.
• The host responds by deasserting CTS. The scanner checks for a deasserted CTS
upon the next transmission of data.
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 the previous communications sequence fails, the scanner issues an error beep. In this
case, the data is lost and must be rescanned.
Note: The DTR signal is jumpered active.
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M2000 Series Product Reference Guide