Denso BHT-7500S Barcode Reader User Manual


 
132
3.5 Communications Protocols
The BHT supports both the BHT-protocol and the BHT-Ir protocol for file transmission.
3.5.1 BHT-protocol
[ 1 ] Overview
The BHT-protocol is the communications procedure used to transmit files between the
BHT and a host (or between the BHTs). It adopts the response method using ACK/NAK
codes.
The BHT-protocol is composed of a defined set of the control character sequences
including the following three phases:
Phase 1: Establishment of data link
The sending station confirms that the receiving station is ready to
receive data.
Phase 2: Data transmission
The sending station transmits data to the target receiving station.
Phase 3: Release of data link
The sending station confirms whether or not all of the transmitted
data has been correctly received by the receiving station. If yes, the
sending station terminates the data transmission and releases the
data link.
For details about the transmission control sequences and horizontal parity checking,
refer to Appendix B, B.1, "BHT-protocol."