W&T 58031, Руководство пользователя, Страница: 53 / 217

53
W&T
Interfaces and displays
Subject to error and alteration
5.2.4 RS422/485 mode
As opposed to RS232, an RS422 interface allows transmission
distances of up to 1000 meters. The RS485 mode allows you to
integrate corresponding 2- or 4-wire bus sytems into a TCP/IP
network with the help of the Com-Server.
1
Especially when using longer cable lengths in
industrial environments, potential differences need to
be taken into consideration. To prevent any resulting
transmission problems or hardware damage, recommended
use of the Com-Server Highspeed Isolated 58633, which has
three galvanically isolated serial ports. Alternately the
galvanic isolation can be achieved by means of an external
isolator (e.g. W&T RS422/485-Isolator Model 66201).
DIP switch setting
SW5
ON
ON
ON
Mode
RS422, RS485
4-wire bus master
RS485 4-wire
automatic control
RS485 2-wire
automatic control
SW1
OFF
OFF
ON
SW2
OFF
ON
ON
SW3
OFF
OFF
OFF
SW6
x
x
x
SW7
x
x
x
SW8
OFF
OFF
OFF
SW4
OFF
OFF
OFF
Pin assignment and function RS422/485, DB9
Pin
1
2
3
4
5
6
7
8
9
Direction
OUT
IN
OUT
IN
---
OUT
IN
OUT
IN
Signal
TxD A/-
RxD A/-
RTS A/-
CTS A/-
GND
TxD B/+
RxD B/+
RTS B/+
CTS B/+
Description
Transmit Data A
Receive Data A
Ready To Send A
Clear To Send A
Signal Ground
Transmit Data B
Receive Data B
Ready To Send B
Clear To Send B
Default function (1)
Data output
Data input
Handshake output
Handshake input
---
Data output
Data input
Handshake output
Handshake input
(1) with factory default setting