System : Iep-7020E-011/012/013, Iep-7021E-011/012/013, Iep-7022E-011/012/013, Iep-7023E-011/012/013 - ASROCK iEP-7020E Series User Manual

2.2.2 System : iEP-7020E-011/012/013, iEP-7021E-011/012/013, iEP-
7022E-011/012/013, iEP-7023E-011/012/013
No. Description
User Define LED : User define LED indicator behaviors are based on the ASRI
1
API library you use.
Serial (COM4) Port* : The 9-pin RS232/422/485 serial connector allows you to
2
connect devices that have serial ports.
* This motherboard supports RS232/422/485 on COM4 port. Please refer to table below for the pin
definition. In addition, COM4 port (RS232/422/485) can be adjusted in BIOS setup utility > Ad-
vanced Screen > Super IO Configuration. You may refer to our user manual for details.
34
2
1
7
8
COM4 Port Pin Definition
Pin RS232
1 DCD, Data Carrier Detect
2 RXD, Receive Data
3 TXD, Transmit Data
4 DTR, Data Terminal Ready
5 GND
6 DSR, Data Set Ready
7 RTS, Request To Send
8 CTS, Clear To Send
9 N/A
3
4
6
5
RS422
TX-
TX+
RX+
RX-
GND
N/A
N/A
N/A
N/A
RS485
RTX-
RTX+
N/A
N/A
GND
N/A
N/A
N/A
N/A