Intermec Transaction Manager 9560, Руководство пользователя

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Data Communications and Operating Options
5-7
5
Point-to-Point accepts and then transmits all data to the host when either:
• the reader receives the EOM character.
• the timeout delay limit is reached.
Polling Mode D Protocol
Polling Mode D protocol is a proprietary Intermec block transfer protocol. It
works in a Point-to-Point environment and supports only one polled device on
the line. Polling Mode D protocol has these characteristics:
Half-duplex This protocol can send or receive data at one time.
Asynchronous
The data is sent one character at a time.
Solicited
The solicitation (POL) and handshake sequences (XON/XOFF) are
enabled and required.
Error checking
The data block includes the LRC for data integrity.
You can set the Terminal Port mode for either transparent or buffered
operation. The default is buffered. See “Displaying Data on a Terminal” later in
this chapter for descriptions of transparent and buffered operation.
If you are connecting the reader to a host computer, you may need to know the
details of Polling Mode D. However, if you are using an Intermec concentrator,
you do not need to understand Polling Mode D. These Intermec concentrators
use Polling Mode D protocol:
• 9160 with Rev. C software or higher
• 9160A and 9161B (Options 01 and 02)
• 9165 System Control Unit
Multi-Drop Protocol
You use Multi-Drop protocol in a data communications network where several
devices are connected to a common line. It is designed to work in an
RS-422/RS-485 environment with up to 32 devices on a single multi-drop
transmission line.
Multi-Drop protocol has the following characteristics:
Half-duplex
This protocol can send or receive data at one time.
Asynchronous
The data is sent one character at a time.
Solicited
The solicitation (POL) and handshake sequences (XON/XOFF) are
enabled and required.
The 9154A and the 9161B Option 02 Intermec controllers support Multi-Drop
protocol.