Rockwell Automation 2755 AdaptaScan Software - Manual (Page 118)

8–9
Publication 2755-838
Special Protocol
Specifies a custom ACK/NAK protocol to communicate with a host.
The ACK character is sent by the host to acknowledge the receipt of
a message. The Reader holds the last transmitted message until
receiving an ACK. The NAK character is sent by the host when a
message is not received, prompting the decoder to resend the
message.
Select To
Enable Use special ACK/NAK protocol.
ACK Enter the decimal equivalent value of an ASCII character from
0 - 255. See Appendix A.
NAK Enter the decimal equivalent value of an ASCII character from
0 - 255. See Appendix A.
Hex Conversion
When selected, messages sent to a host are converted to a
hexadecimal format. Use Hex conversion when sending
non-printable data in a printable format. This option is usually only
used when using APM protocol to configure a Reader (see Scanner
Protocol on page 8–6). The default is disabled.
Transmission Check
Specifies the type of transmission check bytes sent with each
message. Use transmission checks to verify that messages have been
correctly received by the Reader or host device. Appendix D
describes the transmission checks and provides an example.
Select To
None Perform no transmission check.
LRC Enable Longitudinal Redundancy Check characters.
Checksum LSB Enable 16 bit checksum where the least significant byte is
transmitted first.
Checksum MSB Enable 16 bit checksum where the most significant byte is
transmitted first.