Table of Contents
Advertisement
Serial Communication
The VSC 500/700/700D can be remotely controlled via a host
computer or other device (such as a control system) attached to
the rear panel RS-232/422 connector. The control device (host)
can use either Extron's Simple Instruction Set (SIS) commands or
the graphical control program for Windows.
The video scan converter uses a protocol with:
• 9600 baud
• 1 stop bit
• no parity
• no flow control
The rear panel RS-232/422 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
–
No connection
5
Gnd
Signal ground
6
–
No connection
7
–
No connection
8
–
No connection
9
–
No connection
RS-232 Programmer's Guide
Host-to-VSC 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 determines that a command is valid, it
executes the command and sends a response to the host device.
All responses from the VSC to the host end with a carriage
return and a line feed (CR/LF =
the response character string. A string is one or more
characters.
Video scan converter-initiated messages
When a local event such as a front panel selection or adjustment
takes place, the VSC responds by sending a message to the host.
No response is required from the host. The VSC-initiated
messages are listed here (underlined).
(C) Copyright 2002, Extron Electronics, VSC 500, Vx.xx
The VSC sends the copyright message when it first powers on.
Vx.xx is the firmware version number.
3-2
VSC 500/700/700D • Serial Communication
5
1
9
6
DB9 Pin Locations
Female
Pin RS-422 function
Description
1
–
No connection
2
Tx-
Transmit ground
3
Rx-
Receive ground
4
–
No connection
5
Gnd
Signal ground
6
–
No connection
7
Rx+
Receive data
8
Tx+
Transmit data
9
–
No connection
), which signals the end of
Error responses
When the VSC receives a valid SIS command, it executes the
command and sends a response to the host device. If the video
scan converter 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)
Using the command/response tables
The command/response table lists valid command ASCII codes,
the video scan converter's responses to the host, and a
description of the command's function or the results of
executing the command. Lower case characters are acceptable
in the command field unless otherwise indicated. The following
ASCII to HEX conversion table is for use with the
command/response table.
ASCII to HEX Conversion Table
Symbol definitions
=
Picture adjustment range
X10
See the note below.
=
Filter adjustment range (1 - 5)
X11
=
Adjustment range (0 - 127)
X14
=
Escape key
=
CR/LF (carriage return/line
feed) (hex 0D 0A)
The default value for horizontal and vertical size is 0512.
The default values for the horizontal and vertical shift are
2048 and 1024, respectively. The actual minimum and
maximum values will vary and are based on the incoming
scan rate.
VSC 500/700/700D • Serial Communication
•
=
Carriage return (hex 0D)
•
=
Space
=
Horizontal and vertical
X1
frequencies (listed to two
decimal places, e.g.
xx.xx)
=
On/off status where: 0 = off/
X2
disable, 1 = on/enable
3-3
Advertisement
Table of Contents
