Extron Electronics IN1502 User Guide - Manual (Page 30)

IN1502 • Serial Communication 3-2
Serial Communication
The IN1502 can be remotely controlled via a host computer or other device (such
as a control system) attached to the rear panel Remote connector. The control
device (host) uses Extron’s Simple Instruction Set (SIS) commands.
The scaler 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 Input #1 Contact closure
5 Gnd Signal ground
6 Input #2 Contact closure
7 – No connection
8 – No connection
9 Hardwired IR IR input
RS-232 Programmer’s Guide
Host-to-scaler 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 IN1502 determines
that a command is valid, it executes the command and sends a response to the
host device. All responses from the scaler 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.
Scaler-initiated messages
When a local event such as a front panel selection or adjustment takes place, the
IN1502 scaler responds by sending a message to the host. No response is
required from the host. The scaler-initiated messages are listed here
(underlined).
(C) Copyright 2005, Extron Electronics, IN1502, Vx.xx
The IN1502 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 IN1502 sends this response when an input is switched.
Error responses
When the scaler receives a valid SIS command, it executes the command and
sends a response to the host device. If the IN1502 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
E10 – Invalid command
E13 – Invalid value (the number is out of range/too large)
DB9 Pin Locations
Female
5 1
9 6