Contec SBC Series - I;O Addresses and Commands; RS-422;485 Terminating Resistance: JP3

4. Jumper Settings
28
PC-686BX(NLX)-LV, PC-686BX(NLX)-LVV
I/O Addresses and Commands
The table below lists the I/O addresses used by COM2.
Table 4.3. I/O Addresses
I/O Address DLAB Read/Write
W Transmitter hold register THR
R Receiver buffer register RBR
1 W Divisor latch register (LSB) DLL
1 W Divisor latch register (MSB) DLM
0 W Interrupt enable register IER
02FAH X R Interrupt ID register IIR
02FBH X W Line control register LCR
02FCH X W Modem control register MCR
02FDH X R Line status register LSR
02FEH X R Modem status register MSR
02FFH X R/W Scratch register SCR
0
02F8H
02F9H
Register
RS-422/485 Terminating Resistance: JP3
Table 4.4. JP3: RS-422/485 Terminating Resistance
JP3 Terminating resistor
---
CTS for RS-422
RTS for RS-422
RXD for RS-422/485
TXD for RS-422/485
Function
No terminating resistor
(default)
Use terminating resistor
Use terminating resistor
Use terminating resistor
Use terminating resistor
2
1 7
8
2
1 7
8
2
1 7
8
2
1 7
8
2
1 7
8