Serial Communication
The MediaLink 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
MediaLink Controllers User’s Manual.
12V
Switcher protocol:
•9600 baud
•1 stop bit
•no parity
•no flow control
A B C |
Transmit (Tx) 
Receive (Rx)
Sleeve(s)
Ground (
) +12 V, 0.4 A power output
PRELIMINARY
RS-232 Programmer’s Guide
Host-to-MLS 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 MLS 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.
MLS-initiated messages
When a local event such as a front panel selection or adjustment takes place, the MLS responds by sending a message to the host. No response is required from the host. The
Boot V1.00, (c) 2003, ? to Enter
(c)Copyright 2004, Extron Electronics, MLS406MA, Vx.xx ]
The MLS sends the boot and copyright messages when it first powers on. Vx.xx is the firmware version number. The MLS 406MA is used in this example.
Chn X! ] (where X! is the input number)
The MLS sends this response when an input is switched.
Error responses
When the MLS receives a valid SIS command, it executes the command and sends a response to the host device. If the MLS is unable to execute the command because the command is invalid or it contains invalid parameters, it returns an error response to the host.
The error response codes and their descriptions are as follows:
E01 – Invalid input channel number (the number is too large)
E10 – Invalid command
E13 – Invalid value (the number is out of range/too large)
E14 – Invalid for this configuration
E23 – Checksum error (for file uploads)