NTI NODEMUX SERIES UNIVERSAL KVM SWITCH
21
RS232 CONTROL
RS232 Connections and Configuration
Remote Connection
The RS232 Interface is designed to meet the RS232C standard and can be controlled from any terminal (CPU or other controller
with an RS232 communications port.). The pin-out for the DB-9 connector on the unit is as follows:
RS232 Connector (DB-9 FEMALE)
PIN
SIGNAL
FUNCTION
1 CD
Carrier
Detect
2
TXD
Transmit data (RXD at host)
3
RXD
Receive data (TXD at host)
4
DTR
Data terminal ready
5 GND Signal
ground
6
DSR
Data set ready
7
RTS
Request to send
8
CTS
Clear to send
9 -
No
connection
Note: Security must be disabled or user access granted on the port(s) to be selected by RS-232 control
.
On the DB-9 female connector, pins 1 (DCD), 4 (DTR), and 6 (DSR) are shorted and pins 7 (RTS) and 8 (CTS) are shorted.
Therefore, host handshaking is bypassed and TXD and RXD are the only active signals. A straight through DB-9 cable (not null
modem) will work for most CPUs. To daisy chain multiple units, a Matrix Y-1 cable is used (see page 24) for each NODEMUX in
the chain. The last unit will have no connection on its output port and should have DIP switch 1 ON (see table under "Unit
Address and Loop Back" on page 21).
Configuration
Baud Rate
In order for a terminal to communicate with the NODEMUX, the terminal and NODEMUX must each be configured for the same
baud rate.
Press <W> from the Administration Mode menu (page 11) to enter Switch Configuration mode. (Fig. 25)
Press <Tab> once to move the cursor bar to highlight "RS232 BAUD RATE". The default setting is 9600.
Press < > (up arrow) or < > (down arrow) to change the selected baud rate to 300,600,1200,2400,4800, or back to 9600.
Figure 21- Switch Configuration Mode screen
Be careful with
this field. If
changed to
SLAVE, OSD will
not work after
power cycling.
In the event the setting is changed
from "stand alone" to "slave", when
the switch is power cycled the OSD
menu will no longer work. To restore
the setting back to "stand alone",
factory default settings must be
restored via a terminal connected to
the RS232 control port. See the
RS232 Command "CF" on page 24 to
restore default settings.