Thingmagic M6e Bedienungsanleitung PDF herunterladen (Seite 42)

Serial Communication Protocol

A DIVISION OF TRIMBLE

42 Communication Protocol

Serial Communication Protocol

The serial communication between a computer (host) and the M6e is based on a

synchronized command-response/master-slave mechanism. Whenever the host sends a

message to the reader, it cannot send another message until after it receives a response.

The reader never initiates a communication session; only the host initiates a

communication session.

This protocol allows for each command to have its own timeout because some

commands require more time to execute than others. The host must manage retries, if

necessary. The host must keep track of the state of the intended reader if it reissues a

command.

Host-to-Reader Communication

Host-to-reader communication is packetized according to the following diagram. The

reader can only accept one command at a time, and commands are executed serially, so

the host waits for a reader-to-host response before issuing another host-to-reader

command packet.

Header Data Length Command

Data

CRC-16 Checksum

Hdr Len Cmd CRC Hi CRC LO

1 byte 1 byte 1 byte 0 to 250 bytes 2 bytes

1 2 ... 37 38 39 40 41 42 43 44 45 46 47 ... 99 100

Keine Kommentare

Thingmagic M6e Bedienungsanleitung Seite 42