CHAPTER 3 – Jumper Setting

SPI-8450-LLVA 27

Setting the RS-422/RS-485 receiver disable control jumper

When the RS-422/RS-485 port is used, the RTS signal is used for driver enable control

Connecting JRS2 Pins 4 and 6 set to OFF disables the receiver at the same time, preventing the

port from receiving output data to an external device.

3.2.1 RS-422 Setting

RTS#
JRS2: 7-8
TXD#
TX-
RTS-
TX+
RTS+
RX+
CTS+
RX-
CTS-
JRS3: 7-8
JRS3: 5-6
JRS3: 3-4
JRS3: 1-2
D
R
D
R
RXD#
RTS
CTS
COM2
1
2
3
4
5
6
7
8
9
JRS2: 5-6
JRS2: 4-6
120Ω
120Ω
120Ω
120Ω

3.2.2 RS-422 Setting

RTS#
JRS2: 7-8
TXD#
JRS3:7-8
JRS3:5-6
D
R
RXD#
COM2
1
2
3
4
5
6
7
8
9
JRS2: 5-6
JRS2: 4-6
120 Ω
120 Ω
DATA-
DATA+