PS-3710A/PS-3711A Series Hardware Manual
2-28
COM2
COM2 can be changed to either RS-232C, RS-422 or RS-485. (The factory setting is RS-232C.) To change
this setting, open the PS-A unit's rear cover and set slide switch on the circuit board to the desired position.
SEE
Switches (page 2-30)
• Be sure to confirm what settings will be used by the other device and set the slide
switches accordingly. Failure to do so can result in a unit malfunction or damage.
• Whenever changing the PS-A switches, be sure to first turn the PS-A's power
supply OFF. Failure to do so can cause a PS-A malfunction.
Pin Arrangement
Pin No.
RS-232C
Signal Name
Direction
Meaning
1
CD
Input
Carrier Detect
2
RD(RXD)
Input
Receive Data
3
SD(TXD)
Output
Send Data
4
ER(DTR)
Output
Data Terminal Ready
5
GND
-
Signal Ground (SG)
6
DR(DSR)
Input
Data Set Ready
7
RS(RTS)
Output
Request to Send
8
CS(CTS)
Input
Clear to Send
9
CI(RI)
Input
Called status display
FG
FG
-
Frame Ground
(Common with SG)
Pin No.
RS-422
Signal Name
Direction
Meaning
1
RDA
Input
Receive Data A (+)
2
RDB
Input
Receive Data B (-)
3
SDA
Output
Send Data A (+)
4
NC
-
No Connection
5
GND
-
Signal Ground (SG)
6
NC
-
No Connection
7
SDB
Output
Send Data B (-)
8
NC
-
No Connection
9
NC
-
No Connection
FG
FG
-
Frame Ground (Common with SG)
9
6
5
1
(PS-A side)
