Choosing A Communications Protocol - Intermec Janus 2010 User Manual

JANUS 2010 Hand-Held Computer User's Manual
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Communications Manager You can use Communications Manager to transmit
and receive data files, and to request COM port and protocol status. For help,
see "Running Communications Manager" later in this chapter.
JANUS PSK communications application You can create your own
communications application using the software libraries provided with the
JANUS Programmer's Software Kit. For help, see your JANUS PSK reference
manual.
File transfer application for BFT You can use the file transfer application to
transfer binary files. For help, see "Downloading Applications Across the
Network" later in this chapter.
Third-party communications application You can use a third-party
communications application that conforms to the requirements of the JANUS
reader.

Choosing a Communications Protocol

The reader can communicate in any of seven configurable protocols. The
protocols are introduced briefly here. For details about their characteristics and
parameters, see "Communications Protocol, Configure" in Chapter 12.
Multi-Drop Protocol Multi-Drop follows the same protocol sequences as Polling
Mode D with the extension of device addressing, which allows up to 32 devices
on one 4-wire RS-485 twisted pair line. Multi-Drop protocol is typically used in
CrossBar networks. Due to timeout parameters, the baud rate must be 2400 or
higher.
No Protocol No Protocol is for communications applications, such as Interlnk,
that directly access the COM port instead of using a protocol handler. When
you do not use a protocol, you can switch between direct COM port access and
using a protocol handler.
PC Standard Protocol PC Standard handles data transfer on a character-by-
character basis or by either filling a receive buffer or transmitting a buffer of
data. This protocol is designed to be compatible with the standard PC BIOS
functions. The one exception is that the PC Standard protocol can buffer data
that is received to avoid losing characters if a program has not checked for data
recently.
Point-to-Point Protocol Point-to-Point is an unsolicited protocol in which the
reader transmits data whenever it has something to transmit. The data is
followed by a CR LF as the EOM characters. The reader is always in a receiving
state and does not wait for select commands. This protocol does not perform
any error checking or acknowledgment handshaking.
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