Extron Electronics VSC 900_900D User Guide - Manual (Page 32)

VSC 900/900D • Serial Communication 3-2
Serial Communication
The VSC 900/900D can be remotely controlled via a host computer or other
device (such as a control system) attached to the rear panel RS-232 connector.
The control device (host) can use either the Extron Simple Instruction Set (SIS)
commands or the graphical control program for Windows.
The scan converter uses a protocol of 9600 baud, 1 stop bit, no parity, and no
flow control.
The rear panel RS-232 9-pin D connector has the following pin assignments:
Pin RS-232 function Description
1 – No connection
2 Tx Transmit data
3 Rx Receive data
4 Tx 2 Transmit data
5 Gnd Signal ground
6 – No connection
7 – No connection
8 Rx 2 Receive data
9 – No connection
RS-232 Programmer’s Guide
Host-to-scan converter 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 VSC 900/900D
determines that a command is valid, it executes the command and sends a
response to the host device. All responses from the scan converter 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.
It is also possible to send several SIS commands back-to-back in sequence.
Video scan converter-initiated messages
When a local event such as a front panel selection or adjustment takes place, the
VSC 900/900D responds by sending a message to the host. No response is
required from the host. The scan converter-initiated messages are listed here
(underlined).
(C) Copyright 2003, Extron Electronics, VSC 900, Vx.xx
The VSC 900/900D sends the copyright message when it first powers on. Vx.xx
is the firmware version number.
C hn
X1
(where
X1
is the input number)
The VSC 900/900D sends this response when an input is switched.
Error responses
When the scan converter receives a valid SIS command, it executes the command
and sends a response to the host device. If the VSC 900/900D 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)
E09 – Invalid function number (the number is too large)
E10 – Invalid command
E13 – Invalid value (the number is out of range/too large).
DB9 Pin Locations
Female
5 1
9 6