4-21
LT 1804 Product Reference Guide: Programming the LT 1804
Communication Protocols
Hardware Handshaking
The data interface consists of an RS-232C port. See
. The port has been designed to operate either with or without
hardware handshaking lines, RTS, Request to Send, and CTS, Clear to Send.
If RTS/CTS handshaking has not been selected, scan data is transmitted as it
becomes available. If optional RTS/CTS handshaking has been selected, the
DTR signal is hardwired active, and the unit proceeds as follows:
•
Examine CTS. If CTS is not asserted by the host, RTS is asserted by the
scanner. If CTS is asserted by the host, the scanner waits up to 2 seconds
for CTS to be negated.
•
When the host asserts CTS in response to and within the programmable
response timeout period of the scanner's RTS, data is transmitted.
•
The scanner negates RTS after sending the last character.
•
The host should respond by negating CTS. The scanner does not wait for
this but checks before the next transmission, as above.
•
If the above communication attempt fails, the scanner issues an error beep
to alert the operator that the data was not successfully transmitted. In this
case, the data is lost and must be rescanned.
Summary of Contents for LT 1804
Page 82: ...5 27 LT 1804 Product Reference Guide Parameter Menus Baud Rate Continued 4800 1200 2400 9600 ...
Page 102: ...5 47 LT 1804 Product Reference Guide Parameter Menus Prefix Continued 0 1 2 NONE STX ...
Page 103: ...5 48 LT 1804 Product Reference Guide Parameter Menus Prefix Continued 5 3 4 6 7 ...
Page 107: ...5 52 LT 1804 Product Reference Guide Parameter Menus Suffix Continued 2 0 1 3 ...
Page 108: ...5 53 LT 1804 Product Reference Guide Parameter Menus Suffix Continued 5 4 6 7 ...
