UNIMAX Houseware KVM Switch - Manual (Page 34)

NTI UNIMUX MULTI-USER KVM SWITCH
29
NTI
SWITCH
CPU
RS232
First Unit
NTI
SWITCH
RS232
NTI
SWITCH
RS232
Second Unit Last Unit
RS232
Serial Port Matrix-Y-1 Matrix-Y-1 Matrix-Y-1
RS232 CONTROL
RS232 enables the UNIMUX to be remotely controlled via RS232. To control the UNIMUX via RS232 the user has three options:
• write a program that runs on a PC using the Command Protocol (page 31)
• use the Matrix Switcher's Control Program (page 32) provided on the CD
• use the SerTest or RMTEST programs (pages 32 and 34) provided on the CD
Remote Connection
The RS232 Interface is designed to meet the RS232C standard and can be controlled from any host CPU or other controller with
an RS232 communications port. The pin-out for the DB9 connector on the unit is as follows:
RS232 Connector (DB9 FEMALE)
PIN SIGNAL FUNCTION
1 None no connection
2 TXD Transmit Data (RXD at host)
3 RXD Receive Data (TXD at host)
4 DSR Data Set Ready
5 GND Signal Ground
6 DTR Data Terminal Ready
7 CTS Clear to Send
8 RTS Request to Send
9 none no connection
NOTE: Security must be disabled or user access granted on the port(s) to be selected by RS-232 control.
On the DB9 female connector, pins 1 (DCD), 4 (DTR), and 6 (DSR) are shorted and pins 7 (RTS) and 8 (CTS) are shorted.
Therefore, CPU 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, connect a Matrix-Y-1 cable (sold separately) between the CPU
and the first switch, and between each switch (as shown in Figure 34).
Baud Rate
The baud rate can be changed by selecting MENU on the front panel keypad. Then select 1 for SET BAUD RATE and select the
desired baud rate of 9600, 4800, 2400, or 1200. A data protocol of 8 data bits, no parity, and 1 stop bit is used for
communications.
Unit Address and Daisy chaining
To allow multiple units to be controlled from a single host port, the RS232 control interface is designed to allow "daisy chaining" up
to 15 units using an NTI Matrix-Y-1 cable. By setting the appropriate unit address with the keypad, each unit can be given a
unique address (1-15). Then the unit will only respond to commands on the bus if its address is embedded in the command.
To set the unit address;
1. select MENU on the front panel keypad,
2. select 2 for SET UNIT ADDRESS,
3. type the address number (1-15),
4. press <ENTER> on the front panel keypad.
Figure 34- RS232 connection with Matrix-Y-1 cable