9
External Interfaces
• This PL unit’s serial port is not isolated.
When the host (PLC) unit is also not
isolated, and to reduce the risk of dam-
aging the RS-232C/RS-422/RS-485
circuit, be sure to connect pin #5 SG
(Signal Ground) terminal.
• Never connect NC to COM1.
• Connect FG to shell.
Serial Interface
(COM1, COM2, COM3, COM4)
COM1, COM2, COM3, COM4
COM1
*3 To change the communication method, set
the dip switch located on the circuit board in
the PL unit to the desired position.
For details, see [Internal Switches].
Interfit Bracket #4-40 UNC
Pin #
RS-232C
Signal Name
Meaning
1
CD
Carrier Detect
2
RD(RXD)
Receive Data
3
SD(TXD)
Send Data
4
ER(DTR)
Data Terminal Ready
5
SG
Signal Ground
6
DR(DSR)
Data Set Ready
7
RS(RTS)
Request to Send
8
CS(CTS)
Clear to Send
9
CI(RI)/+5V
Called status display/
+5V Output 0.5A
*1
*2
*1 Only COM1 and COM2 are available for
switching to +5 V. COM3 and COM4 are used
exclusively for CI (RI).
*2 Slide switch on the circuit board in the PL unit
switches between CI (RI) and +5 V. For
details, see [Internal Switches].
Shell FG
Frame Ground
(Common with SG)
Pin #
RS-422
*3
Signal Name
Meaning
1
RDA
Receive Data A(+)
2
RDB
Receive Data B(-)
3
SDA
Send Data A(+)
4
ERA
Data Terminal Ready
A(+)
5
SG
Signal Ground
6
CSB
Clear to Send B(-)
7
SDB
Send Data B(-)
8
CSA
Clear to Send A(+)
9
ERB
Data Terminal Ready
B(-)
Shell FG
Frame Ground
(Common with SG)
Pin #
RS-485
*3
Signal Name
Meaning
1
DATA +
Send/Receive Data
(+)
2
DATA -
Send/Receive Data
(-)
3
NC
No Connection
4
NC
No Connection
5
SG
Signal Ground
6
NC
No Connection
7
NC
No Connection
8
NC
No Connection
9
NC
No Connection
Shell FG
Frame Ground
(Common with SG)
