Chapter 2 Hardware Setup
23
COM1/
2:
RS-232/422/485
with
Ring/0V/5V/12V
RS-232
RS-485
PIN
SIGNAL
DESCRIPTION
PIN
SIGNAL
DESCRIPTION
1
DCD
Data
Carrier
Detect
1
485
TXD-
Transmit
Data,
Negative
2
RXD
Receive
Data
2
485
TXD+
Transmit
Data,
Positive
3
TXD
Transmit
Data
3
NC
No
Connection
4
DTR
Data
Terminal
Ready
4
NC
No
Connection
5
GND
Signal
Ground
5
GND
Signal
Ground
6
DSR
Data
Set
Ready
6
NC
No
Connection
7
RTS
Request
To
Send
7
NC
No
Connection
8
CTS
Clear
To
Send
8
NC
No
Connection
9
VCC_CO
M1
Voltage
select
setting
by
J1
9
NC
No
Connection
RS-422
PIN
SIGNAL
DESCRIPTION
1
422
TXD-
Transmit
Data,
Negative
2
422
TXD+
Transmit
Data,
Positive
3
422
RXD+
Receive
Data,
Positive
4
422
RXD-
Receive
Data,
Negative
5
GND
Signal
Ground
6
NC
No
Connection
7
NC
No
Connection
8
NC
No
Connection
9
NC
No
Connection