Rockwell Automation 2755 Enhanced Decoder Series B - Manual (Page 167)

12–5 Configuration: Host Communications
Publication 2755-833
You must define ACK and NAK characters to enable ACK/NAK
protocol with the host. ACK/NAK protocol only applies to bar
code data sent to the host. It is typically used with the
transmission check to provide error detection. You can also use
ACK/NAK protocol to provide flow control.
Start Scan Character
Field Type Options
Edit ASCII
0 through 255
255 = None
This parameter is used with the stop scan character and only applies
when the Decode Mode is set to Host.
Defines the character that tells the scanner(s) to start scanning. There
is a field for both Scanner A and, if present, Scanner B. The default
is None, which means a start scan character is not defined.
①
Stop Scan Character
Field Type Options
Edit ASCII
0 through 255
255 = None
This parameter is used with the start scan character and only applies
when the Decode Mode is set to Host.
Defines the character that tells the scanner(s) to stop scanning. There
is a field for both Scanner A and, if present, Scanner B. The default
is None, which means a stop scan character is not defined.
①
① If any of the characters below are used as single character commands (ACK/NAK or Start/
Characters), then the escape sequence (ESC=!) must be used with all two character comm
start with that character.
A B C D H I M N O P R S T
If the single character commands do not use these uppercase characters, you do not have to
start command sequence. For example, if N is used as the NAK command, then it would b
impossible to send the NR command without preceding it with the ESC=! start command s
If n is used instead, then no start command sequence would be necessary to send an NR co
Therefore, we recommend using only lowercase letters for single character command
Refer to Chapter 15 for additional information.