Rockwell Automation 2755 Cordless Hand-Held Scanner - Manual (Page 55)

3–18 Configuring Your Scanner
Publication 2755-6.3
2. If the CTS line is not active, the base/charger unit will assert the
Request to Send (RTS) line and waits one second for the host to
assert the CTS line. When the host asserts the CTS line, the
base/charger unit transmits the data. During the transmission of
data, the CTS line should be asserted.
3. After the transmission is completed, the base/charger unit will
negate the RTS 10 msec after sending the last character.
4. The host device should then negate CTS. The base/charger unit
checks the CTS line on the next transmission.
If the sequence for scanning data fails, the base/charger unit issues a
transmit error, indicating that the data is lost and must be rescanned.
The default parameter is no Hardware Handshaking enabled.
Software Handshaking
Software handshaking controls the transmission of data. Use
software handshaking instead of (but not with) hardware
handshaking. There are four options:
•
None (Default)
•
ACK/NAK Only
•
ENQ Only
•
ACK/NAK with ENQ
ACK/NAK Only checks the result of a transmission. The
base/charger unit waits for one of the following responses from the
host:
•
<ACK>
•
<NAK>
ACK indicates a successful transmission. NAK indicates there is a
problem. Whenever the scanner receives a NAK, it retransmits the
data up to three times. If an ACK is still not received after three
attempts, the transmission is aborted and the scanner will provide
four short beeps.