Choosing A Protocol Handler - Intermec Janus 2050 User Manual

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Point-to-Point protocol Point-to-Point is an unsolicited protocol in which the
JANUS 2050 transmits data whenever it has something to transmit. The data is
followed by a CR LF as the EOM character. It is always in a receiving state and
does not wait for select commands. This protocol does not perform any error
checking or acknowledgment handshaking.
Point-to-Point protocol is typically used to connect the JANUS 2050 to a CRT
terminal or host computer. Since it is an unsolicited protocol, the transmit
command can be initiated from the JANUS 2050 or the host.
Polling Mode D protocol Polling Mode D requires the host to ask the JANUS
2050 for data it might have (polling) and to request to send data to the JANUS
2050 (selecting). PC-IRL uses this protocol.
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. Due to timeout parameters, the baud
rate must be 2400 or higher.
Multi-Drop protocol is typically used in CrossBar networks.
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 is capable of
buffering data that is received, which avoids losing characters if a program has
not checked for data recently.
RF protocol RF protocol is for use in radio frequency (RF) networks only. For
details, see the JANUS 900 MHz Radio Frequency Quick Reference Guide.
No protocol No protocol is for communications programs, such as
Interlnk/Intersvr, that directly access the COM port instead of using a protocol
handler, which allows you to switch between direct COM port access and
using a protocol handler.

Choosing a Protocol Handler

There are three protocol handlers:
PHIMEC The Intermec protocol handler. PHIMEC lets you communicate with
other Intermec devices such as concentrators.
PHPCSTD The PC Standard protocol handler. PHPCSTD provides low-level
communications abilities and protocol services at the DOS level for non-
communications software. This includes byte-by-byte transfer and status
information.
iconCommunicating With the JANUS 2050
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