Contec SIS-8601-LVA - Page 32

3 Jumper Setting
SIS-8601-LVA
25
Transmit date control in half-duplex mode
In half-duplex mode, the transmission buffer must be controlled to prevent transmit data
from causing a collision. The SIS-8601-LVA uses the RTS signal and bit 1 in the modem
control register to control transmit data.
Modem control register
(Setting I/O address +4H) bit 1: 0 … RTS High (Disables transmission)
1 … RTS low (Enables transmission)
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 JP9 Pins 4 and 6 disables the receiver at the same time, preventing the port from
receiving output data to an external device.
3.3.1 RS-422 Setting
RTS#
JP9: 7-8
TXD
TX-
RTS-
TX+
RTS+
RX+
CTS+
RX-
CTS-
JP10: 7-8
JP10: 5-6
JP10: 3-4
JP10: 1-2
D
R
D
R
RXD
RTS#
CTS#
COM2
1
2
3
4
5
6
7
8
9
JP9: 5-6
JP9: 4-6
120Ω
120Ω
120Ω
120Ω