User Guide Owner's manual
PVS 204SA • Serial Communication
4-2
Serial Communication
PRELIMINARY
The PVS 204SA switcher can be remotely set up and controlled via a host 
computer or other device (such as a control system) attached to the rear panel 
RS-232/MLC/IR port. Alternatively, the switcher can be controlled by an optional 
MediaLink Controller (MLC) (connected to the same port) or by an RS-232 device 
acting through the MLC. The control device (host) can use either Extron’s Simple 
Instruction Set (SIS
™
) commands or the Global Congurator 
(GC2) program for Windows. For details on use and setup 
of a system that includes a MediaLink Controller, refer 
to the MediaLink Controller user’s manual.
Switcher protocol: 
•  9600 baud • 1 stop bit • no parity • no ow control
RS-232/MLC/IR connector pin assignments:
N
  Configuration can also be completed by 
connecting a 2.5 mm stereo mini cable 
(part # 70-335-01) to the 2.5 mm jack (port) 
on the front panel. This port has the same 
protocol as the RS-232 connector on the rear panel.
6 feet
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
Figure 4-1 — Pin out diagram for 2.5 mm mini cable TRS plug when 
connecting to the front panel Config port
N
  Firmware updates can be made only via the front panel Config port.
RS-232 Programmer’s Guide
Host-to-PVS communications
SIS commands consist of one or more characters per field. No special characters are 
required to begin or end a command sequence. When the PVS switcher determines 
that a command is valid, it executes the command and sends a response to the host 
device. All responses from the switcher to the host end with a carriage return and 
a line feed (CR/LF = ]), which signals the end of the response character string. A 
string is one or more characters.
PVS-initiated messages
When a local event such as a front panel selection or adjustment takes place, the 
PVS responds by sending a message to the host. No response is required from the 
host. The PVS-initiated messages are listed here (underlined).
© Copyright 2006, Extron Electronics, PVS 204SA, V1.xx Chn x
The PVS sends the copyright messages when it rst powers on. V1.xx is the 
firmware version number.
Chn X! ] (where X! is the input number) 
The PVS sends this response when an input is switched.
RS-232/MLC/IR
Tx
Rx IR
+12V
A
B
CED
(A) Tr ansmit (Tx)
(B) Receive (Rx)
(C)   IR in
(E) +12 VDC out
(D) Ground ( )










