Model 4P-MAS-30
Page 6
INSTALLATION
Master and Switched Ports
Connection to the Switched A-D ports is made
using 25 pin D Subminiature connectors on the
rear of the unit. The following leads are supported
for Asynchronous communications:
Pin Designation
2
Transmit Data
3
Receive Data
4
Request to Send
5
Clear to Send
6
Data Set Ready
7
Signal Ground
8
Data Carrier Detect
20
Data Terminal Ready
The four switched ports A-D are wired DCE (output data on pin 3,RD). The Master port is wired for as
DTE. To directly connect a terminal device to the Master Port, a Null cable is required. Refer to Figure 3.
RTS / DTR Selection
Jumpers JP1 through JP4 allows selection of RTS or
DTR as the control lead used in the Code/Lead
Control mode. To access these jumpers, disconnect
the power source and remove the top cover of the 4P-
MAS by loosening the two screws on the underside of
the unit. The jumpers are located behind the B and D
Port Connectors. See Figure 4.
Typical
Port A-D
RTS
Mon.
Switch
Control
Code
Mon.
Electronic
4 Way
Switch
2 TD
3 RD
4 RTS
5 CTS
6 DSR
8 DCD
DTR
20
7 SG
2 TD
3 RD
4 RTS
5 CTS
6 DSR
8 DCD
DTR
20
7 SG
Master
Port
Figure 2
System Diagram
2
3
4
5
6
7
8
20
Null Connection to Terminal
Control Leads Required vary from device to
device. Consult your operations manual for
details on your specific needs.
2
3
4
5
6
7
8
20
4P-MAS
Master Port
Figure 3
Null Modem Connection
D
C
B
A
C
B
D
MASTER
A
B
C
D
POWER
A
Port Select
PORT
RTS
DTR
Figure 4
Component Location
