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Communicating With the JANUS 2050
6-5
6
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.
Содержание Janus 2050
Страница 1: ...P N 065716 001 User s Manual JANUS 2050 Vehicle MountComputer 4MB ...
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Страница 21: ......
Страница 22: ...Getting Started 1 ...
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Страница 40: ...Operating the JANUS 2050 2 ...
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Страница 64: ...Using the JANUS 2050 Software 3 ...
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Страница 96: ...Configuring the JANUS 2050 4 ...
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Страница 112: ...Using PC Cards 5 ...
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Страница 132: ...Communicating With the JANUS 2050 6 ...
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Страница 164: ...Working With IRL 7 ...
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Страница 184: ...code 39 nugget helcond Troubleshooting 8 ...
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Страница 210: ...Command Reference 9 ...
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Страница 220: ...Configuration Commands 10 ...
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Страница 316: ...Advanced Operations 11 ...
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Страница 324: ...Configuration and Full ASCII Charts A ...
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Страница 354: ...Specifications B ...
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Страница 366: ...Software Utility Reference C ...
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Страница 406: ...Index I ...
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