-13-
* When SW-A No.4 is off, both on and off are acceptable for No.5.
Example: The driver control for the data of 31H, 9600bps, SW-A No.1-4 off/off/
off(1.35mS)/on is as the following figure.
* RTS and DTR for driver control should be selected by SW-A No.5.
SW-B
Meaning
OFF
ON
No.1 Echo reception of transmission data
With echo back
Without echo back
No.2 Select a line mode
RS-485 (half duplex)
RS-422(full duplex)
No.3 Terminal control between TR+ and TR-. TR signalWithout terminal
control
TR signalWith terminal
control(100 ohm)
No.4 Terminal control between R+ and R-.
R signal Without terminal
control
R signalWith terminal
control(100 ohm)
■ SW-B No.1 (Echo Back Setup)
When you communicate in the half duplex RS-485 mode, setting this switch to ON
prohibits the data, which is sent from the converter to the RS-485 line,from being echoed
back to the USB host.
Therefore, while the driver is active, the ON setting makes the receiver non-active. The
full duplex RS-422 mode does not echo back data even when this switch is in the OFF
setting.
■ SW-B No.2 (Line Mode)
Selects the RS-422/485 line specification which is connected to the converter.
・
OFF (Half Duplex) Setting
This setting makes the converter operate in the half duplex RS-485 mode.
Communicated data is sent and received through TR+ and TR- terminals.
・
ON (Full Duplex) Setting
This setting makes the converter operate in the full duplex RS-422 mode.
Communicated data is sent from TR+ and TR- terminals, and is received to R+ and R-
terminals.
■ SW-B No.3 (Terminal End Between TR+ and TR-)
Setting this switch to ON inserts the terminator 100 ohm between TR+ and TR- in a
direction of parallel.
■ SW-B No.4 (Terminal End Between R+ and R-)
Setting this switch to ON inserts the terminator 100 ohm between R+ and R- in a direction
of parallel.
Start
Bit
1
0
1
0
0
0
1
1
0
0
b0
(LSB)
b1
b6
b5
b4
Stop
Bit
b2
b3
b7
(MSB)
1
Mark
Space
Idle(Mark)
Data
Driver
Control
off
on
Control Signal
RTS/DTR
Active
Non-Active
Internal Timer( 1.35m S )
Driver Active Time