Motorola LS2208-SR20001R Specifications download pdf (Page 97)

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RS-232 Interface

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 scanner reads the CTS line for activity. If CTS is asserted, the scanner waits

up to Host Serial Response Time-out for the host to negate the CTS line. If, after

Host Serial Response Time-out (default), the CTS line is still asserted, the scanner

sounds a transmit error, and any scanned data is lost

• When the CTS line is negated, the 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 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 should respond by negating CTS. The scanner checks for a negated 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 scanner sounds a

transmission error, and the data is discarded.

If the above 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.

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Motorola LS2208-SR20001R Specifications Page 97