Contec SPI-8150-LLVA - RS-232;422;485 Selector: JP8 & JP9

3. Jumper Setting
SPI-8150-LVA, SPI-8151-LVA
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3.5 RS-232/422/485 Selector: JP8 & JP9
RS-232
(Default)
JP9 JP8
2 4 6 8 10 2 4 6 8 10 12 14 16 18 20 22 24
1 3 5 7 9 1 3 5 7 9 11 13 15 17 19 21 23
RS-422
JP9 JP8
2 4 6 8 10 2 4 6 8 10 12 14 16 18 20 22 24
1 3 5 7 9 1 3 5 7 9 11 13 15 17 19 21 23
RS-485
JP9 JP8
2 4 6 8 10 2 4 6 8 10 12 14 16 18 20 22 24
1 3 5 7 9 1 3 5 7 9 11 13 15 17 19 21 23
1. For RS-485, TX+(pin 2) and RX+ (pin 3) must jumper together
inside the D type connector.
2. TX- (pin 1) and RX- (pin 4) is the same.
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 SPI-8150/1-LLVA 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)