Z-World RabbitLink EG2100, Руководство пользователя

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User’s Manual 25
C.2 Serial Communication
C.2.1 Serial Programming Ports
The RabbitLink board has two 10-pin programming headers labeled J8 and J9. The
PROG IN
port
uses the Rabbit 2000’s serial port A for communication, and the PROG OUT port uses serial port B.
The Rabbit 2000 startup-mode pins (SMODE0, SMODE1) are presented to the
PROG IN
port so
that an externally connected device can force a start-up in an external bootstrap mode when the
PROG
connector on either the programming cable or the program download cable is used.
Refer to the Rabbit 2000 Microprocessor User’s Manual for more information related
to the bootstrap mode.
The PROG IN port is used with the DIAG connector on the programming cable to configure the
RabbitLink. The
PROG IN
port transmits information to and from a PC running a terminal emu-
lation program.
The RabbitLink network configuration can be reset through the
PROG IN
port.
The PROG OUT port is used (with the PROG connector on the program download cable con-
nected to the programming port of the target) to download or to debug a program through an Ether-
net-based network or even the Internet to a target Rabbit-based board. The
PROG OUT port
transmits information to and from a PC elsewhere on the Ethernet-based network running Dynamic
C Premier (version 7.02 or later) or the Rabbit Field Utility.
See Appendix D, “Programming Cable,” for more information.
C.2.2 Ethernet Port
The 10 Mbps twisted-pair Ethernet system allows segment lengths of approximately 100 m for
"voice grade" twisted-pair telephone wiring. The maximum segment length may be shorter or
longer than this, depending on the quality of the twisted-pair cabling in your system. While the
10Base-T system is designed to use voice-grade telephone cable that may already be installed,
higher quality Category 5 cables, connectors, and wire terminating devices provide the best possi-
ble signal carrying system for 100 Mbps Ethernet media systems.
The 10Base-T media system uses two pairs of wires, which are terminated in an eight-pin (RJ-45
style) connector. This means that four pins of the eight-pin MDI connector are used as shown in
Figure D-2. The transmit and receive data signals on each pair of a 10Base-T segment are polar-
ized, with one wire of each signal pair carrying the positive (+) signal, and the other carrying the
negative (-) signal.