A&D AD-4405A - Page 70

Page 68 AD-4405A Weighing Indicator
Switching Between RS-422/RS-485
Switching between RS-422/RS-485 is made with the slide switch (SW1) on the
OP-03 board.
Connection
The polarity of signals A and B may vary with different computers.
It is not necessary to ground the SG terminal when using a computer without a signal
ground terminal.
RS-422 RS-485
17. RS-422/RS-485, Relay Output (OP-03)
RDA
RDB
SDA
SDB
SDA
SDB
RDA
RDB
TRM
SDA
SDB
RDA
RDB
TRM
SDA
SDB
RDA
RDB
TRM
SDA
SDB
RDA
RDB
TRM
SDA
SDB
RDA
RDB
TRM
A
B
Some computers have
terminators inside.
SDA
SDB
RDA
RDB
TRM
AD-4405A #32
A
ddress F06=32
AD-4405A #32
A
ddress F06=32
AD-4405A #2
A
ddress F06=2
AD-4405A #2
A
ddress F06=2
AD-4405A #1
A
ddress F06=1
AD-4405A #1
A
ddress F06=1
Host computer
Host computer
Connect a terminator to the
end connection.
Internal termination resister
is effective when the TRM
terminal is connected to the
RDB terminal.