Contec SPC-8520-LA - Setting the RS-422 A;RS-485 Receiver Disable Control Jumper

4. Jumper Setting
SPC-8520-LA, SPC-8521-LA
31
Setting the RS-422A/RS-485 receiver disable control jumper
When the RS-422A/RS-485 port is used, the RTS signal is used for driver enable control Connecting JP2
Pins 4 and 6 set to OFF disable the receiver at the same time, preventing the port from receiving output
data to an external device.
RS-422A Setting
RTS#
JP2: 7-8
TXD#
TX-
RTS-
TX+
RTS+
RX+
CTS+
RX-
CTS-
JP1: 7-8
JP1: 5-6
JP1: 3-4
JP1: 1-2
D
R
D
R
RXD#
RTS
CTS
SERIAL2
1
2
3
4
5
6
7
8
9
JP2: 5-6
JP2: 4-6
120Ω
120Ω
120Ω
120Ω
Figure 4.1. RS-422A Setting
RS-485 Setting
RTS#
JP2: 7-8
TXD#
JP1: 7-8
JP1: 5-6
D
R
RXD#
SERIAL2
1
2
3
4
5
6
7
8
9
JP2: 5-6
JP2: 4-6
120 Ω
120 Ω
DATA-
DATA+
Figure 4.2. RS-485 Setting