Serial-Port Pinout - Black Box 2 x 2 SCSI Matrix Switch SC121A User Manual

2 X 2 SCSI MATRIX SWITCH
Table 5-2. Jumper settings for external termination.
E6-Port A
E5-Port B
The standard factory default connects internal terminators to internal
5 volts.

5.5 Serial-Port Pinout

The SCSI Switch contains two RS-232 serial ports, using DB9 female connectors;
these allow external control of the switch. The connectors are compatible with
standard RS-232 modem cables. The serial ports can be configured to operate
separate communications ports or as daisychained ports.
Daisychained mode allows one computer or terminal to communicate with
multiple SCSI Switches.
Table 5-3. Rear-panel RS-232 connector pinout.
Signal
DCD
RXD
TXD
DTR
GND
DSR
RTS
CTS
RI
26
SC120A-R2
E22-Port 1
E21-Port 2
Description
Data Carrier Detect
Receive Data
Transmit Data
Data Terminal Ready
Signal Ground
Data Set Ready
Request to Send
Clear to Send
Ring Indicator
E19-Port A
E20-Port B
NOTE
DB9 Pin
1
2
3
4
5
6
7
8
9
SC121A
E17-Port 1
E18-Port 2
DB25 Pin
20
22
8
3
2
7
6
4
5