Allen-Bradley 2755-HDG-4 User Manual page 83

Hardware Handshaking
When enabled, handshaking verifies the readiness of a receiving device
before transmitting data. You can enable or disable the hardware
handshaking lines.
This is how the scanner handshaking functions:
1. The scanner checks the Clear to Send (CTS) line. If CTS is active,
the scanner will wait for up to 2 seconds and check the line again. If
the line is still active, the scanner will provide an audible beep and
any scanned data will be lost.
2. If the CTS line is not active, the scanner will assert the Request to
Send (RTS) line and wait for two seconds for the host to assert the
CTS line. When the host asserts the CTS line, the scanner transmits
the data.
3. After the transmission is completed, the scanner negates the RTS.
4. The host device should then negate CTS. The scanner checks the
CTS line on the next transmission.
Communication Setup (Cable Configuration) 4-27
Publication 2755-6.2