If you enable ACK/NAK handshaking (the default), all
packeted messages must have a CMD_ACK or CMD_NAK response, unless
the command description states otherwise. Zebra recommends leaving
this handshaking enabled to provide feedback to the host. Raw decode
data and WAKEUP do not use ACK/NAK handshaking since they are not
packeted data.
Following is an example of a problem which can occur if you disable
ACK/NAK handshaking:
The host sends a PARAM_SEND message to the scanner to change
the baud rate from 9600 to 19200.
The scanner cannot interpret the message.
The scanner does not implement the change the host requested.
The host assumes that the parameter change occurred and acts
accordingly.
Communication is lost because the change did not occur on both
sides.
If you enable ACK/NAK handshaking, the following occurs:
The host sends a PARAM_SEND message.
The scanner cannot interpret the message.
The scanner CMD_NAKs the message.
The host resends the message.
The scanner receives the message successfully, responds with
CMD_ACK, and implements parameter changes.
