User`s manual

DIGITAL-LOGIC AG MSLB-P5 Manual V0.3
PRELIMINARY 38
4.3.5 Serial Ports COM3-COM4 RS422
Select the RS422 Interface with:
J108: 1-2 Select COM3 = RS422
J109: 1-2 Select COM4 = RS422
J115: 2-3 Select COM3 = IRQ10 (1-2 = IRQ4 *)
J114: 2-3 Select COM4 = IRQ11 (1-2 = IRQ3 *)
*) if IRQ3/4 used, the driver must handle the shared IRQ3/4 with the COM1/2 !
On the RS422/485-port the signals of UART have the following functions:
Signal of UART Function of RS485
RxDx RO (Receive Line)
RTSx RE/ (Receiver enable) 0 = Enable, 1 = Disable
DTRx DE (Transceiver enable) 1=Enable, 0= Tristate
TxDx DI (Transmission line)
x stands for 3 or 4 depending of the COM3 or COM4 interface.
Typical Application