Motorola DS6707-DP20411ZZR Reference Guide - Page 141

RS-232 Interface 8 - 11 Check Receive Errors Select whether or not to check the parity, framing, and overrun of received characters. The parity value of received characters is verified against the parity parameter selected above. *Check For Received Errors Do Not 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). Disable Standard RTS/CTS handshaking to transmit scan data as it becomes available. Select Standard RTS/CTS handshaking to transmit scan data 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 discards any scanned data. • 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, the scanner transmits data. 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 completes, 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 data transmission, the CTS line should be asserted. If CTS is deasserted for more than 50 ms between characters, the scanner aborts transmission, sounds a transmission error, and discards the data. If this 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. NOTE The DTR signal is jumpered to the active state.