Check Receive Errors; Hardware Handshaking - Symbol DS6707 Product Reference Manual

Check Receive Errors

Select whether or not the parity, framing, and overrun of received characters are checked. The parity value of
received characters is verified against the parity parameter selected above.
*
Check For Received Errors

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. If
Standard RTS/CTS handshaking is selected, scan data is transmitted according to the following sequence:
• The digital imager scanner reads the CTS line for activity. If CTS is asserted, the digital imager scanner
waits up to Host Serial Response Time-out for the host to de-assert the CTS line. If, after Host Serial
Response Time-out (default), the CTS line is still asserted, the digital imager scanner sounds a transmit
error, and any scanned data is lost.
• When the CTS line is de-asserted, the digital imager scanner asserts the RTS line and waits up to Host
Serial Response Time-out for the host to assert CTS. When the host asserts CTS, data is transmitted. If,
after Host Serial Response Time-out (default), the CTS line is not asserted, the digital imager scanner
sounds a transmit error, and discards the data.
• When data transmission is complete, the digital imager scanner de-asserts RTS 10 msec after sending
the last character.
The host should respond by negating CTS. The digital imager scanner checks for a de-asserted CTS
•
upon the next transmission of data.
During the transmission of data, the CTS line should be asserted. If CTS is deasserted for more than 50 ms
between characters, the transmission is aborted, the digital imager scanner sounds a transmission error, and
the data is discarded.
If the above communication sequence fails, the digital imager 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.
The DTR signal is jumpered to the active state.
NOTE
RS-232 Interface 8 - 11
Do Not Check For Received Errors