Exlar Tritex, Руководство по установке

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Tritex 1 Installation and Setup
123
09/27/12
PN: 27666 Exlar Corporation
Rev. M 952-500-6200M
Communication Converters
Model TT232485 RS232 to 485 Introduction
Model TT232485 is a feature-packed RS-422/485 9-pin converter. It converts
unbalanced, full or half-duplex RS-232 signals to balanced, full or half-duplex RS-422 or
RS-485 signals at baud rates up to 115.2 kbps. In addition the unit optically isolates and
surge suppresses the RS-422/485 lines. The driver uses automatic SD (send data) or
RTS (handshake) control, or can be configured as always enabled for use in RS-422
systems.
A dipswitch selects communication features on the TT232485. Two LEDs show data
traffic in either direction. Only one power supply is necessary, located on the RS-232
side. The isolated power and ground on the RS-422/485 side are generated internally.
Connections are made through a DB9 female connector on the RS-232 side and
terminal blocks on the RS-422/485 side. All terminal blocks, dip switches, and jumpers
are located inside the hood and are reachable through the access panel, which slides
closed to protect the connections.
Description
The RS-232 port has a DB9 female connector with pins 3 (TD), 2 (RD), and 5 (Signal Ground)
supported, pins 7 (RTS) and 8 (CTS) are tied together, and pins 6 (DSR), 1 (CD), and 4 (DTR),
are also tied together. The 485OT9L has two LEDs: a Transmit Data LED showing when data
goes from the RS-232 side to the RS-485 side, and a Receive Data LED showing data going
from the RS-485 side to the RS-232 side. These are very useful for determining if data is getting
through the converter. The RS-485 terminal blocks support Transmit Data (A) and (B), Receive
Data (A) and (B), and Signal Ground. A single supply voltage of 10 to 30 VDC on the RS-232
side powers the unit. An 8-position dipswitch allows the selection of baud rate, 2-wire or 4-wire
mode, echo on or off, and termination in or out.
RS-422/485 Driver Control
The TT232485 uses either RTS Control or Send Data Control to enable the RS-485 driver. This
option is user selectable by setting push-on jumpers located next to the terminal blocks. RTS
controls the driver using toggling Request to Send (pin 7) of the RS-232 side. Raising RTS
enables the driver and lowering RTS disables it. Automatic Send Data Control recognizes the
first bit of data from the RS-232 side, enables the transmitter and disables the receiver. After the
last bit of data is sent from the RS-232 side, the TT232485 waits one character length then
disables the transmitter and enables the receiver. The timeout can be selected with dipswitches
or by changing the value of R21 (see Table, Baud Rate Selection). The timeout is preset at the
factory for 9600 baud. Removing both sets of jumpers completely will constantly enable the RS-
485 driver. This makes the TT232485 behave like an RS-422 converter. For settings, see Table,
Standard Communications Settings.