Extron Electronics MLA-VC10 - Manual (Page 42)

MLA-VC10 • Configuration and Operation
Configuration and Operation, cont’d
3-14
RS-232 control
The RS-232 protocol for the MLA-VC10 is 9600 baud, 1 stop bit,
no parity, and no flow control.
The control device (host) can use Extron Simple Instruction Set
(SIS) commands.
The MLA has a 5-pole captive screw connector for
connecting to the MLC and power. The connector
has the following pin assignments:
A = Transmit, B = Receive, C = Not Used,
= Ground, + = +12 VDC input
Host-to-MLA communications
SIS commands consist of one or more characters per field. No
special characters are required to begin or end a command
sequence. When a command is valid, the MLA executes
that command and sends a response to the host device. All
responses from the interface 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.
MLA-initiated messages
When the MLA is powered up, it sends the following message
(underlined here) to the host:
(C) Copyright 2002, Extron Electronics, MLA-VC10
]
No response is required from the host. The MLA may also send
a message of Volxxx, where xxx represents the setting for the
percentage of maximum volume.
Error response
When the MLA receives a valid SIS command, it executes the
command and sends a response to the host device. If the MLA is
unable to execute the command because the command contains
invalid parameters, it returns the following error response to the
host:
E13 − Invalid value (the number is out of range/too large)
A B C