Installation User guide
Installation, cont’d
MLC 226 IP Series • Installation
2-4
PRELIMINARY
The front panel 2.5 mm mini stereo connector Confi g port serves the same 
RS-232 function as this rear panel port but is independent from it.
N
 Both confi guration ports require 38400 baud communication. This is a higher 
speed than many other Extron products use. The Global Confi gurator (GC) 
software automatically sets the connection for the appropriate speed. If using 
HyperTerminal or a similar application, make sure the PC or control system 
connected to these ports is set for 38400 baud.
Digital input/output: pin 1 and the ground pin together act as a digital input/
output port (depending on confi guration). This allows for an additional way 
to trigger events or functions (such as triggering relays, issuing commands, or 
sending an e-mail) that have been confi gured using GC.
Digital input: when this port is confi gured as a digital input, it is set to 
measure two states: high and low. The threshold voltages are as follows: a 
voltage below 2.0 VDC is measured as logic low, and a voltage above 2.8 VDC 
is measured as logic high. There is also an internal, +5 VDC, selectable, pull-
up resistor for this circuit.
Digital output — When this port is confi gured as a digital output, it offers 
two output states: on and off. When the port is set to an “on” state, (the 
circuit is closed), the I/O pin is connected to ground. Each I/O port is capable 
of accepting 250 mA, maximum. When the port is set to the “off” state (the 
circuit is open), the output pin is fl oating.
If the application calls for TTL compatibility, the circuit can be set up to 
provide a 2k ohm pull-up resistor to +5 VDC.
b
 Front panel Confi g (host control) port — This 2.5 mm mini stereo jack serves 
the same RS-232 function as the rear panel Host Control port, but it is easier 
to access than the rear port after the MLC has been installed and cabled. The 
optional 9-pin D to 2.5 mm stereo mini TRS RS-232 cable (part #70-335-01, 
shown below) can be used for this connection. This port has the same 
protocol as the rear panel port mentioned above but does not offer digital 
input.
RS-232 protocol:
• 38400 baud
• 1 stop bit
• no parity
• 8 data bits
• no fl ow control
N
 Both confi guration ports require 38400 baud communication. This is a higher 
speed than many other Extron products use. Global Confi gurator software 
may automatically set the connection for the appropriate speed. If using 
HyperTerminal or a similar application, make sure the PC or control system 
connected to these ports is set for 38400 baud.
N
  Extron recommends confi guring and controlling the MLC via the LAN 
connector. Ethernet connections are faster and more reliable.
6 feet
(1.8 m)
Part #70-335-01
5
1
9
6
Sleeve (Gnd)
Ring
Tip
9-pin D Connection TRS Plug
Pin 2 Computer's RX line Tip
Pin 3 Computer's TX line Ring
Pin 5 Computer's signal ground Sleeve
6 feet
(1.8 m)
Part #70-335-01
5
1
9
6
Sleeve (Gnd)
Ring
Tip
9-pin D Connection TRS Plug
Pin 2 Computer's RX line Tip
Pin 3 Computer's TX line Ring
Pin 5 Computer's signal ground Sleeve










