Neousys Technology POC-400 Series, User Manual

Page: 71 / 99

POC-400 Series
71
4.1 COM1 Port Configuration
The system
’
s COM1 port supports RS-232 (full-duplex), RS-422 (full-duplex) and
RS-485 (half-duplex) mode. You can set the COM1 operating mode via BIOS
settings. Another option in BIOS called “
Slew Rate
” defines how sharp the
rising/falling edge is for the output signal of COM1. For long-distance RS-422/485
transmission, you m
ay set the “
Slew Rate
” option as “High” to improve signal quality.
For RS-422/485 communication, the
“
RS-422/485 Termination
”
option determines
whether to enable/disable internal termination of RS-422/485 transceiver according
to your wiring configuration (e.g. with or without external termination).
To set COM1 operating mode:
1. Press F2 when the system boots up to enter the BIOS setup utility.
2. Go to [Advanced]
→
[Peripheral Configuration] .
3. Set the [Set COM1 Mode as] option to the desired mode.
4. Once set, press F10 to save setting and exit.