Computer Hardware User Manual

VIPER Technical Manual Connectors, LEDs and jumpers

RS485/422 configuration – LK4, LK5, LK6 and LK7 on JP1

These jumpers are used to enable/disable the RS485 receive buffer and RS485/422

line termination. See

436HCOM5 – RS422/485 interface, page 437H65, for more details.

LK4 Description

(RS485 TX/RX) RS422 TX line

termination resistor (120Ω) connected.

(RS485 TX/RX) RS422 TX line

termination resistor (120Ω)

disconnected.

LK5 Description

RS422 RX line termination resistor

(120Ω) connected.

RS422 RX line termination resistor

(120Ω) disconnected.

LK6 & LK7 Description

RS422 full-duplex.

RS485 half-duplex.

Only fit LK4 and LK5 if the VIPER is at the end of the network.

Default setting: